1Template::Alloy(3) User Contributed Perl Documentation Template::Alloy(3)
2
6 Template::Alloy - TT2/3, HT, HTE, Tmpl, and Velocity Engine
7
9 Template::Toolkit style usage
10 my $t = Template::Alloy->new(
11 INCLUDE_PATH => ['/path/to/templates'],
12 );
13 my $swap = {
15 key1 => 'val1',
16 key2 => 'val2',
17 code => sub { 42 },
18 hash => {a => 'b'},
19 };
20 # print to STDOUT
22 $t->process('my/template.tt', $swap)
23 || die $t->error;
24 # process into a variable
26 my $out = '';
27 $t->process('my/template.tt', $swap, \$out);
28 ### Alloy uses the same syntax and configuration as Template::Toolkit
30 HTML::Template::Expr style usage
32 my $t = Template::Alloy->new(
33 filename => 'my/template.ht',
34 path => ['/path/to/templates'],
35 );
36 my $swap = {
38 key1 => 'val1',
39 key2 => 'val2',
40 code => sub { 42 },
41 hash => {a => 'b'},
42 };
43 $t->param($swap);
45 # print to STDOUT (errors die)
47 $t->output(print_to => \*STDOUT);
48 # process into a variable
50 my $out = $t->output;
51 ### Alloy can also use the same syntax and configuration as HTML::Template
53 Text::Tmpl style usage
55 my $t = Template::Alloy->new;
56 my $swap = {
58 key1 => 'val1',
59 key2 => 'val2',
60 code => sub { 42 },
61 hash => {a => 'b'},
62 };
63 $t->set_delimiters('#[', ']#');
65 $t->set_strip(0);
66 $t->set_values($swap);
67 $t->set_dir('/path/to/templates');
68 my $out = $t->parse_file('my/template.tmpl');
70 my $str = "Foo #[echo $key1]# Bar";
72 my $out = $t->parse_string($str);
73 ### Alloy uses the same syntax and configuration as Text::Tmpl
76 Velocity (VTL) style usage
78 my $t = Template::Alloy->new;
79 my $swap = {
81 key1 => 'val1',
82 key2 => 'val2',
83 code => sub { 42 },
84 hash => {a => 'b'},
85 };
86 my $out = $t->merge('my/template.vtl', $swap);
88 my $str = "#set($foo 1 + 3) ($foo) ($bar) ($!baz)";
90 my $out = $t->merge(\$str, $swap);
91
93 "An alloy is a homogeneous mixture of two or more elements"
94 (http://en.wikipedia.org/wiki/Alloy).
95 Template::Alloy represents the mixing of features and capabilities from
97 all of the major mini-language based template systems (support for non-
98 mini-language based systems will happen eventually). With
99 Template::Alloy you can use your favorite template interface and syntax
100 and get features from each of the other major template systems. And
101 Template::Alloy is fast - whether your using mod_perl, cgi, or running
102 from the commandline. There is even Template::Alloy::XS for getting a
103 little more speed when that is necessary.
104 Template::Alloy happened by accident (accidentally on purpose). The
106 Template::Alloy (Alloy hereafter) was originally a part of the CGI::Ex
107 suite that performed simple variable interpolation. It used TT2 style
108 variables in TT2 style tags "[% foo.bar %]". That was all the original
109 Template::Alloy did. This was fine and dandy for a couple of years.
110 In winter of 2005-2006 Alloy was revamped to add a few features. One
111 thing led to another and soon Alloy provided for most of the features
112 of TT2 as well as some from TT3. Template::Alloy now provides a full-
113 featured implementation of the Template::Toolkit language.
114 After a move to a new company that was using HTML::Template::Expr and
116 Text::Tmpl templates, support was investigated and interfaces for
117 HTML::Template, HTML::Template::Expr, Text::Tmpl, and Velocity (VTL)
118 were added. All of the various engines offer the same features - just
119 using different syntaxes and interfaces.
120 Template::Toolkit brought the most to the table. HTML::Template
122 brought the LOOP directive. HTML::Template::Expr brough more vmethods
123 and using vmethods as top level functions. Text::Tmpl brought the
124 COMMENT directive and encouraged speed matching (Text::Tmpl is almost
125 entirely C based and is very fast). The Velocity engine brought
126 AUTO_EVAL and SHOW_UNDEFINED_INTERP.
127 Most of the standard Template::Toolkit documentation covering
129 directives, variables, configuration, plugins, filters, syntax, and
130 vmethods should apply to Alloy just fine (This pod tries to explain
131 everything - but there is too much). See Template::Alloy::TT for a
132 listing of the differences between Alloy and TT.
133 Most of the standard HTML::Template and HTML::Template::Expr
135 documentation covering methods, variables, expressions, and syntax will
136 apply to Alloy just fine as well.
137 Most of the standard Text::Tmpl documentation applies, as does the
139 documentation covering Velocity (VTL).
140 So should you use Template::Alloy ? Well, try it out. It may give you
142 no visible improvement. Or it could.
143
145 Template::Alloy uses a recursive regex based grammar (early versions
146 during the CGI::Ex::Template phase did not). This allows for the
147 embedding of opening and closing tags inside other tags (as in [% a =
148 "[% 1 + 2 %]" ; a|eval %]). The individual methods such as parse_expr
149 and play_expr may be used by external applications to add TT style
150 variable parsing to other applications.
151 The regex parser returns an AST (abstract syntax tree) of the text,
153 directives, variables, and expressions. All of the different template
154 syntaxes compile to the same AST format. The AST is composed only of
155 scalars and arrayrefs and is suitable for sending to JavaScript via
156 JSON or sharing with other languages. The parse_tree method is used
157 for returning this AST.
158 Once at the AST stage, there are two modes of operation. Alloy can
160 either operate directly on the AST using the Play role, or it can
161 compile the AST to perl code via the Compile role, and then execute the
162 code. To use the perl code route, you must set the COMPILE_PERL flag
163 to 1. If you are running in a cached-in-memory environment such as
164 mod_perl, this is the fastest option. If you are running in a non-
165 cached-in-memory environment, then using the Play role to run the AST
166 is generally faster. The AST method is also more secure as cached AST
167 won't ever eval any "perl" (assuming PERL blocks are disabled - which
168 is the default).
169
171 Template::Alloy has split out its functionality into discrete roles.
172 In Template::Toolkit, this functionality is split into separate
173 classes. The roles in Template::Alloy simply add on more methods to
174 the main class. When Perl 6 arrives, these roles will be translated
175 into true Roles.
176 The following is a list of roles used by Template::Alloy.
178 Template::Alloy::Compile - Compile-to-perl role
180 Template::Alloy::HTE - HTML::Template::Expr role
181 Template::Alloy::Operator - Operator role
182 Template::Alloy::Parse - Parse-to-AST role
183 Template::Alloy::Play - Play-AST role
184 Template::Alloy::Stream - Stream output role
185 Template::Alloy::Tmpl - Text::Tmpl role
186 Template::Alloy::TT - Template::Toolkit role
187 Template::Alloy::Velocity - Velocity role
188 Template::Alloy::VMethod - Virtual methods role
189 Template::Alloy automatically loads the roles when they are needed or
191 requested - but not sooner (with the exception of the Operator role and
192 the VMethod role which are always needed and always loaded). This is
193 good for a CGI environment. In mod_perl you may want to preload a role
194 to make the most of shared memory. You may do this by passing either
195 the role name or a method supplied by that role.
196 # import roles necessary for running TT
198 use Template::Alloy qw(Parse Play Compile TT);
199 # import roles based on methods
201 use Template::Alloy qw(parse_tree play_tree compile_tree process);
202 Note: importing roles by method names does not import them into that
204 namespace - it is autoloading the role and methods into the
205 Template::Alloy namespace. To help make this more clear you may use
206 the following syntax as well.
207 # import roles necessary for running TT
209 use Template::Alloy load => qw(Parse Play Compile TT);
210 # import roles based on methods
212 use Template::Alloy load => qw(process parse_tree play_tree compile_tree);
213 # import roles based on methods
215 use Template::Alloy
216 Parse => 1,
217 Play => 1,
218 Compile => 1,
219 TT => 1;
220 Even with all roles loaded Template::Alloy is still relatively small.
222 You can load all of the roles by pass "all" to the use statement.
223 use Template::Alloy 'all';
225 # or
227 use Template::Alloy load => 'all';
228 # or
230 use Template::Alloy all => 1;
231 As a final option, Template::Alloy also includes the ability to stand-
233 in for other template modules. It is able to do this because it
234 supports the majority of the interface of the other template systems.
235 You can do this in the following way:
236 use Template::Alloy qw(Text::Tmpl HTML::Template);
238 # or
240 use Template::Alloy load => qw(Text::Tmpl HTML::Template);
241 # or
243 use Template::Alloy
244 'Text::Tmpl' => 1,
245 'HTML::Template' => 1;
246 Note that the use statement will die if any of the passed module names
248 are already loaded and not subclasses of Template::Alloy. This will
249 avoid thinking that you are using Template::Alloy when you really
250 aren't. Using the 'all' option won't automatically do this - you must
251 mention the "stood-in" modules by name.
252 The following modules may be "stood-in" for:
254 Template
256 Text::Tmpl
257 HTML::Template
258 HTML::Template::Expr
259 This feature is intended to make using Template::Alloy with existing
261 code easier. Most cases should work just fine. Almost all syntax will
262 just work (except Alloy may make some things work that were previously
263 broken). However Template::Alloy doesn't support 100% of the interface
264 of any of the template systems. If you are using "features-on-the-
265 edge" then you may need to re-write portions of your code that interact
266 with the template system.
267
269 The following section lists most of the publicly available methods.
270 Some less commonly used public methods are listed later in this
271 document.
272 "new"
274 my $obj = Template::Alloy->new({
275 INCLUDE_PATH => ['/my/path/to/content', '/my/path/to/content2'],
276 });
277 Arguments may be passed as a hash or as a hashref. Returns a
279 Template::Alloy object.
280 There are currently no errors during Template::Alloy object
282 creation. If you are using the HTML::Template interface, this is
283 different behavior. The document is not parsed until the output or
284 process methods are called.
285 "process"
287 This is the TT interface for starting processing. Any errors that
288 result in the template processing being stopped will be stored and
289 available via the ->error method.
290 my $t = Template::Alloy->new;
292 $t->process($in, $swap, $out)
293 || die $t->error;
294 Process takes three arguments.
296 The $in argument can be any one of:
298 String containing the filename of the template to be processed. The filename should
300 be relative to INCLUDE_PATH. (See INCLUDE_PATH, ABSOLUTE, and RELATIVE configuration items).
301 In memory caching and file side caching are available for this type.
302 A reference to a scalar containing the contents of the template to be processed.
304 A coderef that will be called to return the contents of the template.
306 An open filehandle that will return the contents of the template when read.
308 The $swap argument should be hashref containing key value pairs
310 that will be available to variables swapped into the template.
311 Values can be hashrefs, hashrefs of hashrefs and so on, arrayrefs,
312 arrayrefs of arrayrefs and so on, coderefs, objects, and simple
313 scalar values such as numbers and strings. See the section on
314 variables.
315 The $out argument can be any one of:
317 undef - meaning to print the completed template to STDOUT.
319 String containing a filename. The completed template will be placed in the file.
321 A reference to a string. The contents will be appended to the scalar reference.
323 A coderef. The coderef will be called with the contents as a single argument.
325 An object that can run the method "print". The contents will be passed as
327 a single argument to print.
328 An arrayref. The contents will be pushed onto the array.
330 An open filehandle. The contents will be printed to the open handle.
332 Additionally - the $out argument can be configured using the OUTPUT
334 configuration item.
335 The process method defaults to using the "cet" syntax which will
337 parse TT3 and most TT2 documents. To parse HT or HTE documents,
338 you must pass the SYNTAX configuration item to the "new" method.
339 All calls to process would then default to HTE syntax.
340 my $obj = Template::Alloy->new(SYNTAX => 'hte');
342 "process_simple"
344 Similar to the process method but with the following restrictions:
345 The $in parameter is limited to a filename or a reference a string
347 containing the contents.
348 The $out parameter may only be a reference to a scalar string that
350 output will be appended to.
351 Additionally, the following configuration variables will be
353 ignored: VARIABLES, PRE_DEFINE, BLOCKS, PRE_PROCESS, PROCESS,
354 POST_PROCESS, AUTO_RESET, OUTPUT.
355 "error"
357 Should something go wrong during a "process" command, the error
358 that occurred can be retrieved via the error method.
359 $obj->process('somefile.html', {a => 'b'}, \$string_ref)
361 || die $obj->error;
362 "output"
364 HTML::Template way to process a template. The output method
365 requires that a filename, filehandle, scalarref, or arrayref
366 argument was passed to the new method. All of the HT calling
367 conventions for new are supported. The key difference is that
368 Alloy will not actually process the template until the output
369 method is called.
370 my $obj = Template::Alloy->new(filename => 'myfile.html');
372 $obj->param(\%swap);
373 print $obj->output;
374 See the HTML::Template documentation for more information.
376 The output method defaults to using the "hte" syntax which will
378 parse HTE and HT documents. To parse TT3 or TT2 documents, you
379 must pass the SYNTAX configuration item to the "new" method. All
380 calls to process would then default to TT3 syntax.
381 my $obj = Template::Alloy->new(SYNTAX => 'tt3');
383 Any errors that occur during the output method will die with the
385 error as the die value.
386 "param"
388 HTML::Template way to get or set variable values that will be used
389 by the output method.
390 my $val = $obj->param('key'); # get one value
392 $obj->param(key => $val); # set one value
394 $obj->param(key => $val, key2 => $val2); # set multiple
396 $obj->param({key => $val, key2 => $val2}); # set multiple
398 See the HTML::Template documentation for more information.
400 Note: Alloy does not support the die_on_bad_params configuration.
402 This is because Alloy does not resolve variable names until the
403 output method is called.
404 "define_vmethod"
406 This method is available for defining extra Virtual methods or
407 filters. This method is similar to
408 Template::Stash::define_vmethod.
409 Template::Alloy->define_vmethod(
411 'text',
412 reverse => sub { my $item = shift; return scalar reverse $item },
413 );
414 "register_function"
416 This is the HTML::Template way of defining text vmethods. It is
417 the same as calling define_vmethod with "text" as the first
418 argument.
419 Template::Alloy->register_function(
421 reverse => sub { my $item = shift; return scalar reverse $item },
422 );
423 "define_directive"
425 This method can be used for adding new directives or overridding
426 existing ones.
427 Template::Alloy->define_directive(
429 MYDIR => {
430 parse_sub => sub {}, # parse additional items in the tag
431 play_sub => sub {
432 my ($self, $ref, $node, $out_ref) = @_;
433 $$out_ref .= "I always say the same thing!";
434 return;
435 },
436 is_block => 1, # is this block like
437 is_postop => 0, # not a post operative directive
438 no_interp => 1, # no interpolation in this block
439 continues => undef, # it doesn't "continue" any other directives
440 },
441 );
442 Now with a template like:
444 my $str = "([% MYDIR %]This is something[% END %])";
446 Template::Alloy->new->process(\$str);
447 You will get:
449 (I always say the same thing!)
451 We'll add more details in later revisions of this document.
453 "define_syntax"
455 This method can be used for adding other syntaxes to or overridding
456 existing ones in the list of choices available in Alloy. The
457 syntax can be chosen by the SYNTAX configuration item.
458 Template::Alloy->define_syntax(
460 my_uber_syntax => sub {
461 my $self = shift;
462 local $self->{'V2PIPE'} = 0;
463 local $self->{'V2EQUALS'} = 0;
464 local $self->{'PRE_CHOMP'} = 0;
465 local $self->{'POST_CHOMP'} = 0;
466 local $self->{'NO_INCLUDES'} = 0;
467 return $self->parse_tree_tt3(@_);
468 },
469 );
470 The subroutine that is used must return an opcode tree (AST) that
472 can be played by the execute_tree method.
473 "define_operator"
475 This method allows for adding new operators or overriding existing
476 ones.
477 Template::Alloy->define_operator({
479 type => 'right', # can be one of prefix, postfix, right, left, none, ternary, assign
480 precedence => 84, # relative precedence for resolving multiple operators without parens
481 symbols => ['foo', 'FOO'], # any mix of chars can be used for the operators
482 play_sub => sub {
483 my ($one, $two) = @_;
484 return "You've been foo'ed ($one, $two)";
485 },
486 });
487 You can then use it in a template as in the following:
489 my $str = "[% 'ralph' foo 1 + 2 * 3 %]";
491 Template::Alloy->new->process(\$str);
492 You will get:
494 You've been foo'ed (ralph, 7)
496 Future revisions of this document will include more samples. This
498 is an experimental feature and the api will probably change.
499 "dump_parse_tree"
501 This method allows for returning a Data::Dumper dump of a parsed
502 template. It is mainly used for testing.
503 "dump_parse_expr"
505 This method allows for returning a Data::Dumper dump of a parsed
506 variable. It is mainly used for testing.
507 "import"
509 All of the arguments that can be passed to "use" that are listed
510 above in the section dealing with ROLES, can be used with the
511 import method.
512 # import by role
514 Template::Alloy->import(qw(Compile Play Parse TT));
515 # import by method
517 Template::Alloy->import(qw(compile_tree play_tree parse_tree process));
518 # import by "stand-in" class
520 Template::Alloy->import('Text::Tmpl', 'HTML::Template::Expr');
521 As mentioned in the ROLE section - arguments passed to import are
523 not imported into current namespace. Roles and methods are only
524 imported into the Template::Alloy namespace.
525
527 This section discusses how to use variables and expressions in the TT
528 mini-language.
529 A variable is the most simple construct to insert into the TT mini
531 language. A variable name will look for the matching value inside
532 Template::Alloys internal stash of variables which is essentially a
533 hash reference. This stash is initially populated by either passing a
534 hashref as the second argument to the process method, or by setting the
535 "VARIABLES" or "PRE_DEFINE" configuration variables.
536 If you are using the HT and HTE syntaxes, the VAR, IF, UNLESS, LOOP,
538 and INCLUDE directives will accept a NAME attribute which may only be a
539 single level (non-chained) HTML::Template variable name, or they may
540 accept an EXPR attribute which may be any valid TT3 variable or
541 expression.
542 The following are some sample ways to access variables.
544 ### some sample variables
546 my %vars = (
547 one => '1.0',
548 foo => 'bar',
549 vname => 'one',
550 some_code => sub { "You passed me (".join(', ', @_).")" },
551 some_data => {
552 a => 'A',
553 bar => 3234,
554 c => [3, 1, 4, 1, 5, 9],
555 vname => 'one',
556 },
557 my_list => [20 .. 50],
558 cet => Template::Alloy->new,
559 );
560 ### pass the variables into the Alloy process
562 $cet->process($template_name, \%vars)
563 || die $cet->error;
564 ### pass the variables during object creation (will be available to every process call)
566 my $cet = Template::Alloy->new(VARIABLES => \%vars);
567 GETTING VARIABLES
569 Once you have variables defined, they can be used directly in the
570 template by using their name in the stash. Or by using the GET
571 directive.
572 [% foo %]
574 [% one %]
575 [% GET foo %]
576 Would print when processed:
578 bar
580 1.0
581 bar
582 To access members of a hashref or an arrayref, you can chain together
584 the names using a ".".
585 [% some_data.a %]
587 [% my_list.0] [% my_list.1 %] [% my_list.-1 %]
588 [% some_data.c.2 %]
589 Would print:
591 A
593 20 21 50
594 4
595 If the value of a variable is a code reference, it will be called. You
597 can add a set of parenthesis and arguments to pass arguments.
598 Arguments are variables and can be as complex as necessary.
599 [% some_code %]
601 [% some_code() %]
602 [% some_code(foo) %]
603 [% some_code(one, 2, 3) %]
604 Would print:
606 You passed me ().
608 You passed me ().
609 You passed me (bar).
610 You passed me (1.0, 2, 3).
611 If the value of a variable is an object, methods can be called using
613 the "." operator.
614 [% cet %]
616 [% cet.dump_parse_expr('1 + 2').replace('\s+', ' ') %]
618 Would print something like:
620 Template::Alloy=HASH(0x814dc28)
622 $VAR1 = [ [ undef, '+', '1', '2' ], 0 ];
624 Each type of data (string, array and hash) have virtual methods
626 associated with them. Virtual methods allow for access to functions
627 that are commonly used on those types of data. For the full list of
628 built in virtual methods, please see the section titled VIRTUAL METHODS
629 [% foo.length %]
631 [% my_list.size %]
632 [% some_data.c.join(" | ") %]
633 Would print:
635 3
637 31
638 3 | 1 | 4 | 5 | 9
639 It is also possible to "interpolate" variable names using a "$". This
641 allows for storing the name of a variable inside another variable. If
642 a variable name is a little more complex it can be embedded inside of
643 "${" and "}".
644 [% $vname %]
646 [% ${vname} %]
647 [% ${some_data.vname} %]
648 [% some_data.$foo %]
649 [% some_data.${foo} %]
650 Would print:
652 1.0
654 1.0
655 1.0
656 3234
657 3234
658 In Alloy it is also possible to embed any expression (non-directive) in
660 "${" and "}" and it is possible to use non-integers for array access.
661 (This is not available in TT2)
662 [% ['a'..'z'].${ 2.3 } %]
664 [% {ab => 'AB'}.${ 'a' ~ 'b' } %]
665 [% color = qw/Red Blue/; FOR [1..4] ; color.${ loop.index % color.size } ; END %]
666 Would print:
668 c
670 AB
671 RedBlueRedBlue
672 SETTING VARIABLES.
674 To define variables during processing, you can use the = operator. In
675 most cases this is the same as using the SET directive.
676 [% a = 234 %][% a %]
678 [% SET b = "Hello" %][% b %]
679 Would print:
681 234
683 Hello
684 It is also possible to create arrayrefs and hashrefs.
686 [% a = [1, 2, 3] %]
688 [% b = {key1 => 'val1', 'key2' => 'val2'} %]
689 [% a.1 %]
691 [% b.key1 %] [% b.key2 %]
692 Would print:
694 2
696 val1 val2
697 It is possible to set multiple values in the same SET directive.
699 [% SET a = 'A'
701 b = 'B'
702 c = 'C' %]
703 [% a %] [% b %] [% c %]
704 Would print:
706 A B C
708 It is also possible to unset variables, or to set members of nested
710 data structures.
711 [% a = 1 %]
713 [% SET a %]
714 [% b.0.c = 37 %]
716 ([% a %])
718 [% b.0.c %]
719 Would print
721 ()
723 37
724
726 The following are the types of literals (numbers and strings) and
727 constructors (hash and array constructs) allowed in Alloy. They can be
728 used as arguments to functions, in place of variables in directives,
729 and in place of variables in expressions. In Alloy it is also possible
730 to call virtual methods on literal values.
731 Integers and Numbers.
733 [% 23423 %] Prints an integer.
734 [% 3.14159 %] Prints a number.
735 [% pi = 3.14159 %] Sets the value of the variable.
736 [% 3.13159.length %] Prints 7 (the string length of the number)
737 Scientific notation is supported.
739 [% 314159e-5 + 0 %] Prints 3.14159.
741 [% .0000001.fmt('%.1e') %] Prints 1.0e-07
743 Hexidecimal input is also supported.
745 [% 0xff + 0 %] Prints 255
747 [% 48875.fmt('%x') %] Prints beeb
749 Single quoted strings.
751 Returns the string. No variable interpolation happens.
752 [% 'foobar' %] Prints "foobar".
754 [% '$foo\n' %] Prints "$foo\\n". # the \\n is a literal "\" and an "n"
755 [% 'That\'s nice' %] Prints "That's nice".
756 [% str = 'A string' %] Sets the value of str.
757 [% 'A string'.split %] Splits the string on ' ' and returns the list.
758 Note: virtual methods can only be used on literal strings in Alloy,
760 not in TT.
761 You may also embed the current tags in strings (Alloy only).
763 [% '[% 1 + 2 %]' | eval %] Prints "3"
765 Double quoted strings.
767 Returns the string. Variable interpolation happens.
768 [% "foobar" %] Prints "foobar".
770 [% "$foo" %] Prints "bar" (assuming the value of foo is bar).
771 [% "${foo}" %] Prints "bar" (assuming the value of foo is bar).
772 [% "foobar\n" %] Prints "foobar\n". # the \n is a newline.
773 [% str = "Hello" %] Sets the value of str.
774 [% "foo".replace('foo','bar') %] Prints "bar".
775 Note: virtual methods can only be used on literal strings in Alloy,
777 not in TT.
778 You may also embed the current tags in strings (Alloy only).
780 [% "[% 1 + 2 %]" | eval %] Prints "3"
782 Array Constructs.
784 [% [1, 2, 3] %] Prints something like ARRAY(0x8309e90).
785 [% array1 = [1 .. 3] %] Sets the value of array1.
786 [% array2 = [foo, 'a', []] %] Sets the value of array2.
787 [% [4, 5, 6].size %] Prints 3.
788 [% [7, 8, 9].reverse.0 %] Prints 9.
789 Note: virtual methods can only be used on array contructs in Alloy,
791 not in TT.
792 Quoted Array Constructs.
794 [% qw/1 2 3/ %] Prints something like ARRAY(0x8309e90).
795 [% array1 = qw{Foo Bar Baz} %] Sets the value of array1.
796 [% qw[4 5 6].size %] Prints 3.
797 [% qw(Red Blue).reverse.0 %] Prints Blue.
798 Note: this works in Alloy and is planned for TT3.
800 Hash Constructs.
802 [% {foo => 'bar'} %] Prints something like HASH(0x8305880)
803 [% hash = {foo => 'bar', c => {}} %] Sets the value of hash.
804 [% {a => 'A', b => 'B'}.size %] Prints 2.
805 [% {'a' => 'A', 'b' => 'B'}.size %] Prints 2.
806 [% name = "Tom" %]
807 [% {Tom => 'You are Tom',
808 Kay => 'You are Kay'}.$name %] Prints You are Tom
809 Note: virtual methods can only be used on hash contructs in Alloy,
811 not in TT.
812 Regex Constructs.
814 [% /foo/ %] Prints (?-xism:foo)
815 [% a = /(foo)/i %][% "FOO".match(a).0 %] Prints FOO
816 Note: this works in Alloy and is planned for TT3.
818
820 Virtual methods (vmethods) are a TT feature that allow for operating on
821 the swapped template variables.
822 This document shows some samples of using vmethods. For a full listing
824 of available virtual methods, see Template::Alloy::VMethod.
825
827 Expressions are one or more variables or literals joined together with
828 operators. An expression can be used anywhere a variable can be used
829 with the exception of the variable name in the SET directive, and the
830 filename of PROCESS, INCLUDE, WRAPPER, and INSERT.
831 For a full listing of operators, see Template::Alloy::Operator.
833 The following section shows some samples of expressions. For a full
835 list of available operators, please see the section titled OPERATORS.
836 [% 1 + 2 %] Prints 3
838 [% 1 + 2 * 3 %] Prints 7
839 [% (1 + 2) * 3 %] Prints 9
840 [% x = 2 %] # assignments don't return anything
842 [% (x = 2) %] Prints 2 # unless they are in parens
843 [% y = 3 %]
844 [% x * (y - 1) %] Prints 4
845
847 This section contains the alphabetical list of DIRECTIVES available in
848 Alloy. DIRECTIVES are the "functions" and control structures that work
849 in the various mini-languages. For further discussion and examples
850 beyond what is listed below, please refer to the TT directives
851 documentation or to the appropriate documentation for the particular
852 directive.
853 The examples given in this section are done using the Template::Toolkit
855 syntax, but can be done in any of the various syntaxes. See
856 Template::Alloy::TT, Template::Alloy::HTE, Template::Alloy::Tmpl, and
857 Template::Alloy::Velocity.
858 [% IF 1 %]One[% END %]
860 [% FOREACH a = [1 .. 3] %]
861 a = [% a %]
862 [% END %]
863 [% SET a = 1 %][% SET a = 2 %][% GET a %]
865 In TT multiple directives can be inside the same set of '[%' and '%]'
867 tags as long as they are separated by space or semi-colons (;) (The
868 Alloy version of Tmpl allows multiple also - but none of the other
869 syntaxes do). Any block directive that can also be used as a post-
870 operative directive (such as IF, WHILE, FOREACH, UNLESS, FILTER, and
871 WRAPPER) must be separated from preceding directives with a semi-colon
872 if it is being used as a block directive. It is more safe to always
873 use a semi-colon. Note: separating by space is only available in Alloy
874 but is a planned TT3 feature.
875 [% SET a = 1 ; SET a = 2 ; GET a %]
877 [% SET a = 1
878 SET a = 2
879 GET a
880 %]
881 [% GET 1
883 IF 0 # is a post-operative
884 GET 2 %] # prints 2
885 [% GET 1;
887 IF 0 # it is block based
888 GET 2
889 END
890 %] # prints 1
891 The following is the list of directives.
893 "BLOCK"
895 Saves a block of text under a name for later use in PROCESS,
896 INCLUDE, and WRAPPER directives. Blocks may be placed anywhere
897 within the template being processed including after where they are
898 used.
899 [% BLOCK foo %]Some text[% END %]
901 [% PROCESS foo %]
902 Would print
904 Some text
906 [% INCLUDE foo %]
908 [% BLOCK foo %]Some text[% END %]
909 Would print
911 Some text
913 Anonymous BLOCKS can be used for capturing.
915 [% a = BLOCK %]Some text[% END %][% a %]
917 Would print
919 Some text
921 Anonymous BLOCKS can be used with macros.
923 "BREAK"
925 Alias for LAST. Used for exiting FOREACH and WHILE loops.
926 "CALL"
928 Calls the variable (and any underlying coderefs) as in the GET
929 method, but always returns an empty string.
930 "CASE"
932 Used with the SWITCH directive. See the "SWITCH" directive.
933 "CATCH"
935 Used with the TRY directive. See the "TRY" directive.
936 "CLEAR"
938 Clears any of the content currently generated in the innermost
939 block or template. This can be useful when used in conjunction
940 with the TRY statement to clear generated content if an error
941 occurs later.
942 "COMMENT"
944 Will comment out any text found between open and close tags. Note,
945 that the intermediate items are still parsed and END tags must
946 align - but the parsed content will be discarded.
947 [% COMMENT %]
949 This text won't be shown.
950 [% IF 1 %]And this won't either.[% END %]
951 [% END %]
952 "CONFIG"
954 Allow for changing the value of some compile time and runtime
955 configuration options.
956 [% CONFIG
958 ANYCASE => 1
959 PRE_CHOMP => '-'
960 %]
961 The following compile time configuration options may be set:
963 ANYCASE
965 AUTO_EVAL
966 CACHE_STR_REFS
967 ENCODING
968 INTERPOLATE
969 POST_CHOMP
970 PRE_CHOMP
971 SEMICOLONS
972 SHOW_UNDEFINED_INTERP
973 SYNTAX
974 V1DOLLAR
975 V2EQUALS
976 V2PIPE
977 The following runtime configuration options may be set:
979 ADD_LOCAL_PATH
981 CALL_CONTEXT
982 DUMP
983 VMETHOD_FUNCTIONS
984 If non-named parameters as passed, they will show the current
986 configuration:
987 [% CONFIG ANYCASE, PRE_CHOMP %]
989 CONFIG ANYCASE = undef
991 CONFIG PRE_CHOMP = undef
992 "DEBUG"
994 Used to reset the DEBUG_FORMAT configuration variable, or to turn
995 DEBUG statements on or off. This only has effect if the DEBUG_DIRS
996 or DEBUG_ALL flags were passed to the DEBUG configuration variable.
997 [% DEBUG format '($file) (line $line) ($text)' %]
999 [% DEBUG on %]
1000 [% DEBUG off %]
1001 "DEFAULT"
1003 Similar to SET, but only sets the value if a previous value was not
1004 defined or was zero length.
1005 [% DEFAULT foo = 'bar' %][% foo %] => 'bar'
1007 [% foo = 'baz' %][% DEFAULT foo = 'bar' %][% foo %] => 'baz'
1009 "DUMP"
1011 DUMP inserts a Data::Dumper printout of the variable or expression.
1012 If no argument is passed it will dump the entire contents of the
1013 current variable stash (with private keys removed).
1014 The output also includes the current file and line number that the
1016 DUMP directive was called from.
1017 See the DUMP configuration item for ways to customize and control
1019 the output available to the DUMP directive.
1020 [% DUMP %] # dumps everything
1022 [% DUMP 1 + 2 %]
1024 "ELSE"
1026 Used with the IF directive. See the "IF" directive.
1027 "ELSIF"
1029 Used with the IF directive. See the "IF" directive.
1030 "END"
1032 Used to end a block directive.
1033 "EVAL"
1035 Same as the EVALUATE directive.
1036 "EVALUATE"
1038 Introduced by the Velocity templating language. Parses and
1039 processes the contents of the passed item. This is similar to the
1040 eval filter, but Velocity needs a directive. Named arguments may
1041 be used for reconfiguring the parser. Any of the items that can be
1042 passed to the CONFIG directive may be passed here.
1043 [% EVALUATE "[% 1 + 3 %]" %]
1045 [% foo = "bar" %]
1047 [% EVALUATE "<TMPL_VAR foo>" SYNTAX => 'ht' %]
1048 "FILTER"
1050 Used to apply different treatments to blocks of text. It may
1051 operate as a BLOCK directive or as a post operative directive.
1052 Alloy supports all of the filters in Template::Filters. The lines
1053 between scalar virtual methods and filters is blurred (or non-
1054 existent) in Alloy. Anything that is a scalar virtual method may
1055 be used as a FILTER.
1056 TODO - enumerate the at least 7 ways to pass and use filters.
1058 '|' Alias for the FILTER directive. Note that | is similar to the '.'
1060 in Template::Alloy. Therefore a pipe cannot be used directly after
1061 a variable name in some situations (the pipe will act only on that
1062 variable). This is the behavior employed by TT3. To get the TT2
1063 behavior for a PIPE, use the V2PIPE configuration item.
1064 "FINAL"
1066 Used with the TRY directive. See the "TRY" directive.
1067 "FOR"
1069 Alias for FOREACH
1070 "FOREACH"
1072 Allows for iterating over the contents of any arrayref. If the
1073 variable is not an arrayref, it is automatically promoted to one.
1074 [% FOREACH i IN [1 .. 3] %]
1076 The variable i = [% i %]
1077 [%~ END %]
1078 [% a = [1 .. 3] %]
1080 [% FOREACH j IN a %]
1081 The variable j = [% j %]
1082 [%~ END %]
1083 Would print:
1085 The variable i = 1
1087 The variable i = 2
1088 The variable i = 3
1089 The variable j = 1
1091 The variable j = 2
1092 The variable j = 3
1093 You can also use the "=" instead of "IN" or "in".
1095 [% FOREACH i = [1 .. 3] %]
1097 The variable i = [% i %]
1098 [%~ END %]
1099 Same as before.
1101 Setting into a variable is optional.
1103 [% a = [1 .. 3] %]
1105 [% FOREACH a %] Hi [% END %]
1106 Would print:
1108 hi hi hi
1110 If the item being iterated is a hashref and the FOREACH does not
1112 set into a variable, then values of the hashref are copied into the
1113 variable stash.
1114 [% FOREACH [{a => 1}, {a => 2}] %]
1116 Key a = [% a %]
1117 [%~ END %]
1118 Would print:
1120 Key a = 1
1122 Key a = 2
1123 The FOREACH process uses the Template::Alloy::Iterator class to
1125 handle iterations (It is compatible with Template::Iterator).
1126 During the FOREACH loop an object blessed into the iterator class
1127 is stored in the variable "loop".
1128 The loop variable provides the following information during a
1130 FOREACH:
1131 index - the current index
1133 max - the max index of the list
1134 size - the number of items in the list
1135 count - index + 1
1136 number - index + 1
1137 first - true if on the first item
1138 last - true if on the last item
1139 next - return the next item in the list
1140 prev - return the previous item in the list
1141 The following:
1143 [% FOREACH [1 .. 3] %] [% loop.count %]/[% loop.size %] [% END %]
1145 Would print:
1147 1/3 2/3 3/3
1149 The iterator is also available using a plugin. This allows for
1151 access to multiple "loop" variables in a nested FOREACH directive.
1152 [%~ USE outer_loop = Iterator(["a", "b"]) %]
1154 [%~ FOREACH i = outer_loop %]
1155 [%~ FOREACH j = ["X", "Y"] %]
1156 [% outer_loop.count %]-[% loop.count %] = ([% i %] and [% j %])
1157 [%~ END %]
1158 [%~ END %]
1159 Would print:
1161 1-1 = (a and X)
1163 1-2 = (a and Y)
1164 2-1 = (b and X)
1165 2-2 = (b and Y)
1166 FOREACH may also be used as a post operative directive.
1168 [% "$i" FOREACH i = [1 .. 5] %] => 12345
1170 "GET"
1172 Return the value of a variable or expression.
1173 [% GET a %]
1175 The GET keyword may be omitted.
1177 [% a %]
1179 [% 7 + 2 - 3 %] => 6
1181 See the section on VARIABLES.
1183 "IF (IF / ELSIF / ELSE)"
1185 Allows for conditional testing. Expects an expression as its only
1186 argument. If the expression is true, the contents of its block are
1187 processed. If false, the processor looks for an ELSIF block. If
1188 an ELSIF's expression is true then it is processed. Finally it
1189 looks for an ELSE block which is processed if none of the IF or
1190 ELSIF's expressions were true.
1191 [% IF a == b %]A equaled B[% END %]
1193 [% IF a == b -%]
1195 A equaled B
1196 [%- ELSIF a == c -%]
1197 A equaled C
1198 [%- ELSE -%]
1199 Couldn't determine that A equaled anything.
1200 [%- END %]
1201 IF may also be used as a post operative directive.
1203 [% 'A equaled B' IF a == b %]
1205 Note: If you are using HTML::Template style documents, the TMPL_IF
1207 tag parses using the limited HTML::Template parsing rules.
1208 However, you may use EXPR="" to embed a TT3 style expression.
1209 "INCLUDE"
1211 Parse the contents of a file or block and insert them. Variables
1212 defined or modifications made to existing variables are discarded
1213 after a template is included.
1214 [% INCLUDE path/to/template.html %]
1216 [% INCLUDE "path/to/template.html" %]
1218 [% file = "path/to/template.html" %]
1220 [% INCLUDE $file %]
1221 [% BLOCK foo %]This is foo[% END %]
1223 [% INCLUDE foo %]
1224 Arguments may also be passed to the template:
1226 [% INCLUDE "path/to/template.html" a = "An arg" b = "Another arg" %]
1228 Filenames must be relative to INCLUDE_PATH unless the ABSOLUTE or
1230 RELATIVE configuration items are set.
1231 Multiple filenames can be passed by separating them with a plus, a
1233 space, or commas (TT2 doesn't support the comma). Any supplied
1234 arguments will be used on all templates.
1235 [% INCLUDE "path/to/template.html",
1237 "path/to/template2.html" a = "An arg" b = "Another arg" %]
1238 On Perl 5.6 on some platforms there may be some issues with the
1240 variable localization. There is no problem on 5.8 and greater.
1241 "INSERT"
1243 Insert the contents of a file without template parsing.
1244 Filenames must be relative to INCLUDE_PATH unless the ABSOLUTE or
1246 RELATIVE configuration items are set.
1247 Multiple filenames can be passed by separating them with a plus, a
1249 space, or commas (TT2 doesn't support the comma).
1250 [% INSERT "path/to/template.html",
1252 "path/to/template2.html" %]
1253 "LAST"
1255 Used to exit out of a WHILE or FOREACH loop.
1256 "LOOP"
1258 This directive operates similar to the HTML::Template loop
1259 directive. The LOOP directive expects a single variable name.
1260 This variable name should point to an arrayref of hashrefs. The
1261 keys of each hashref will be added to the variable stash when it is
1262 iterated.
1263 [% var a = [{b => 1}, {b => 2}, {b => 3}] %]
1265 [% LOOP a %] ([% b %]) [% END %]
1267 Would print:
1269 (1) (2) (3)
1271 If Alloy is in HT mode and GLOBAL_VARS is false, the contents of
1273 the hashref will be the only items available during the loop
1274 iteration.
1275 If LOOP_CONTEXT_VARS is true, and $QR_PRIVATE is false (default
1277 when called through the output method), then the variables
1278 __first__, __last__,
1279 __inner__, __odd__, and __counter__ will be set. See the
1280 HTML::Template loop_context_vars configuration item for more
1281 information.
1282 "MACRO"
1284 Takes a directive and turns it into a variable that can take
1285 arguments.
1286 [% MACRO foo(i, j) BLOCK %]You passed me [% i %] and [% j %].[% END %]
1288 [%~ foo("a", "b") %]
1290 [% foo(1, 2) %]
1291 Would print:
1293 You passed me a and b.
1295 You passed me 1 and 2.
1296 Another example:
1298 [% MACRO bar(max) FOREACH i = [1 .. max] %]([% i %])[% END %]
1300 [%~ bar(4) %]
1302 Would print:
1304 (1)(2)(3)(4)
1306 Starting with version 1.012 of Template::Alloy there is also a
1308 macro operator.
1309 [% foo = ->(i,j){ "You passed me $i and $j" } %]
1311 [% bar = ->(max){ FOREACH i = [1 .. max]; i ; END } %]
1313 See the Template::Alloy::Operator documentation for more examples.
1315 "META"
1317 Used to define variables that will be available via either the
1318 template or component namespace.
1319 Once defined, they cannot be overwritten.
1321 [% template.foobar %]
1323 [%~ META foobar = 'baz' %]
1324 [%~ META foobar = 'bing' %]
1325 Would print:
1327 baz
1329 "NEXT"
1331 Used to go to the next iteration of a WHILE or FOREACH loop.
1332 "PERL"
1334 Only available if the EVAL_PERL configuration item is true (default
1335 is false).
1336 Allow eval'ing the block of text as perl. The block will be parsed
1338 and then eval'ed.
1339 [% a = "BimBam" %]
1341 [%~ PERL %]
1342 my $a = "[% a %]";
1343 print "The variable \$a was \"$a\"";
1344 $stash->set('b', "FooBar");
1345 [% END %]
1346 [% b %]
1347 Would print:
1349 The variable $a was "BimBam"
1351 FooBar
1352 During execution, anything printed to STDOUT will be inserted into
1354 the template. Also, the $stash and $context variables are set and
1355 are references to objects that mimic the interface provided by
1356 Template::Context and Template::Stash. These are provided for
1357 compatibility only. $self contains the current Template::Alloy
1358 object.
1359 "PROCESS"
1361 Parse the contents of a file or block and insert them. Unlike
1362 INCLUDE, no variable localization happens so variables defined or
1363 modifications made to existing variables remain after the template
1364 is processed.
1365 [% PROCESS path/to/template.html %]
1367 [% PROCESS "path/to/template.html" %]
1369 [% file = "path/to/template.html" %]
1371 [% PROCESS $file %]
1372 [% BLOCK foo %]This is foo[% END %]
1374 [% PROCESS foo %]
1375 Arguments may also be passed to the template:
1377 [% PROCESS "path/to/template.html" a = "An arg" b = "Another arg" %]
1379 Filenames must be relative to INCLUDE_PATH unless the ABSOLUTE or
1381 RELATIVE configuration items are set.
1382 Multiple filenames can be passed by separating them with a plus, a
1384 space, or commas (TT2 doesn't support the comma). Any supplied
1385 arguments will be used on all templates.
1386 [% PROCESS "path/to/template.html",
1388 "path/to/template2.html" a = "An arg" b = "Another arg" %]
1389 "RAWPERL"
1391 Only available if the EVAL_PERL configuration item is true (default
1392 is false). Similar to the PERL directive, but you will need to
1393 append to the $output variable rather than just calling PRINT.
1394 "RETURN"
1396 Used to exit the innermost block or template and continue
1397 processing in the surrounding block or template.
1398 There are two changes from TT2 behavior. First, In Alloy, a RETURN
1400 during a MACRO call will only exit the MACRO. Second, the RETURN
1401 directive takes an optional variable name or expression, if passed,
1402 the MACRO will return this value instead of the normal text from
1403 the MACRO. The process_simple method will also return this value.
1404 You can also use the item, list, and hash return vmethods.
1406 [% RETURN %] # just exits
1408 [% RETURN "foo" %] # return value is foo
1409 [% "foo".return %] # same thing
1410 "SET"
1412 Used to set variables.
1413 [% SET a = 1 %][% a %] => "1"
1415 [% a = 1 %][% a %] => "1"
1416 [% b = 1 %][% SET a = b %][% a %] => "1"
1417 [% a = 1 %][% SET a %][% a %] => ""
1418 [% SET a = [1, 2, 3] %][% a.1 %] => "2"
1419 [% SET a = {b => 'c'} %][% a.b %] => "c"
1420 "STOP"
1422 Used to exit the entire process method (out of all blocks and
1423 templates). No content will be processed beyond this point.
1424 "SWITCH"
1426 Allow for SWITCH and CASE functionality.
1427 [% a = "hi" %]
1429 [% b = "bar" %]
1430 [% SWITCH a %]
1431 [% CASE "foo" %]a was foo
1432 [% CASE b %]a was bar
1433 [% CASE ["hi", "hello"] %]You said hi or hello
1434 [% CASE DEFAULT %]I don't know what you said
1435 [% END %]
1436 Would print:
1438 You said hi or hello
1440 "TAGS"
1442 Change the type of enclosing braces used to delineate template
1443 tags. This remains in effect until the end of the enclosing block
1444 or template or until the next TAGS directive. Either a named set
1445 of tags must be supplied, or two tags themselves must be supplied.
1446 [% TAGS html %]
1448 [% TAGS <!-- --> %]
1450 The named tags are (duplicated from TT):
1452 asp => ['<%', '%>' ], # ASP
1454 default => ['\[%', '%\]' ], # default
1455 html => ['<!--', '-->' ], # HTML comments
1456 mason => ['<%', '>' ], # HTML::Mason
1457 metatext => ['%%', '%%' ], # Text::MetaText
1458 php => ['<\?', '\?>' ], # PHP
1459 star => ['\[\*', '\*\]' ], # TT alternate
1460 template => ['\[%', '%\]' ], # Normal Template Toolkit
1461 template1 => ['[\[%]%', '%[%\]]'], # allow TT1 style
1462 tt2 => ['\[%', '%\]' ], # TT2
1463 If custom tags are supplied, by default they are escaped using
1465 quotemeta. You may also pass explicitly quoted strings, or regular
1466 expressions as arguments as well (if your regex begins with a ', ",
1467 or / you must quote it.
1468 [% TAGS [<] [>] %] matches "[<] tag [>]"
1470 [% TAGS '[<]' '[>]' %] matches "[<] tag [>]"
1472 [% TAGS "[<]" "[>]" %] matches "[<] tag [>]"
1474 [% TAGS /[<]/ /[>]/ %] matches "< tag >"
1476 [% TAGS ** ** %] matches "** tag **"
1478 [% TAGS /**/ /**/ %] Throws an exception.
1480 You should be sure that the start tag does not include grouping
1482 parens or INTERPOLATE will not function properly.
1483 "THROW"
1485 Allows for throwing an exception. If the exception is not caught
1486 via the TRY DIRECTIVE, the template will abort processing of the
1487 directive.
1488 [% THROW mytypes.sometime 'Something happened' arg1 => val1 %]
1490 See the TRY directive for examples of usage.
1492 "TRY"
1494 The TRY block directive will catch exceptions that are thrown while
1495 processing its block (It cannot catch parse errors unless they are
1496 in included files or evaltt'ed strings. The TRY block will then
1497 look for a CATCH block that will be processed. While it is being
1498 processed, the "error" variable will be set with the thrown
1499 exception as the value. After the TRY block - the FINAL block will
1500 be ran whether or not an error was thrown (unless a CATCH block
1501 throws an error).
1502 Note: Parse errors cannot be caught unless they are in an eval
1504 FILTER, or are in a separate template being INCLUDEd or PROCESSed.
1505 [% TRY %]
1507 Nothing bad happened.
1508 [% CATCH %]
1509 Caught the error.
1510 [% FINAL %]
1511 This section runs no matter what happens.
1512 [% END %]
1513 Would print:
1515 Nothing bad happened.
1517 This section runs no matter what happens.
1518 Another example:
1520 [% TRY %]
1522 [% THROW "Something happened" %]
1523 [% CATCH %]
1524 Error: [% error %]
1525 Error.type: [% error.type %]
1526 Error.info: [% error.info %]
1527 [% FINAL %]
1528 This section runs no matter what happens.
1529 [% END %]
1530 Would print:
1532 Error: undef error - Something happened
1534 Error.type: undef
1535 Error.info: Something happened
1536 This section runs no matter what happens.
1537 You can give the error a type and more information including named
1539 arguments. This information replaces the "info" property of the
1540 exception.
1541 [% TRY %]
1543 [% THROW foo.bar "Something happened" "grrrr" foo => 'bar' %]
1544 [% CATCH %]
1545 Error: [% error %]
1546 Error.type: [% error.type %]
1547 Error.info: [% error.info %]
1548 Error.info.0: [% error.info.0 %]
1549 Error.info.1: [% error.info.1 %]
1550 Error.info.args.0: [% error.info.args.0 %]
1551 Error.info.foo: [% error.info.foo %]
1552 [% END %]
1553 Would print something like:
1555 Error: foo.bar error - HASH(0x82a395c)
1557 Error.type: foo.bar
1558 Error.info: HASH(0x82a395c)
1559 Error.info.0: Something happened
1560 Error.info.1: grrrr
1561 Error.info.args.0: Something happened
1562 Error.info.foo: bar
1563 You can also give the CATCH block a type to catch. And you can
1565 nest TRY blocks. If types are specified, Alloy will try and find
1566 the closest matching type. Also, an error object can be re-thrown
1567 using $error as the argument to THROW.
1568 [% TRY %]
1570 [% TRY %]
1571 [% THROW foo.bar "Something happened" %]
1572 [% CATCH bar %]
1573 Caught bar.
1574 [% CATCH DEFAULT %]
1575 Caught default - but rethrew.
1576 [% THROW $error %]
1577 [% END %]
1578 [% CATCH foo %]
1579 Caught foo.
1580 [% CATCH foo.bar %]
1581 Caught foo.bar.
1582 [% CATCH %]
1583 Caught anything else.
1584 [% END %]
1585 Would print:
1587 Caught default - but rethrew.
1589 Caught foo.bar.
1591 "UNLESS"
1593 Same as IF but condition is negated.
1594 [% UNLESS 0 %]hi[% END %] => hi
1596 Can also be a post operative directive.
1598 "USE"
1600 Allows for loading a Template::Toolkit style plugin.
1601 [% USE iter = Iterator(['foo', 'bar']) %]
1603 [%~ iter.get_first %]
1604 [% iter.size %]
1605 Would print:
1607 foo
1609 2
1610 Note that it is possible to send arguments to the new object
1612 constructor. It is also possible to omit the variable name being
1613 assigned. In that case the name of the plugin becomes the
1614 variable.
1615 [% USE Iterator(['foo', 'bar', 'baz']) %]
1617 [%~ Iterator.get_first %]
1618 [% Iterator.size %]
1619 Would print:
1621 foo
1623 3
1624 Plugins that are loaded are looked up for in the namespace listed
1626 in the PLUGIN_BASE directive which defaults to Template::Plugin.
1627 So in the previous example, if Template::Toolkit was installed, the
1628 iter object would loaded by the class Template::Plugin::Iterator.
1629 In Alloy, an effective way to disable plugins is to set the
1630 PLUGIN_BASE to a non-existent base such as "_" (In TT it will still
1631 fall back to look in Template::Plugin).
1632 Note: The iterator plugin will fall back and use
1634 Template::Alloy::Iterator if Template::Toolkit is not installed.
1635 No other plugins come installed with Template::Alloy.
1636 The names of the Plugin being loaded from PLUGIN_BASE are case
1638 insensitive. However, using case insensitive names is bad as it
1639 requires scanning the @INC directories for any module matching the
1640 PLUGIN_BASE and caching the result (OK - not that bad).
1641 If the plugin is not found and the LOAD_PERL directive is set, then
1643 Alloy will try and load a module by that name (note: this type of
1644 lookup is case sensitive and will not scan the @INC dirs for a
1645 matching file).
1646 # The LOAD_PERL directive should be set to 1
1648 [% USE ta = Template::Alloy %]
1649 [%~ ta.dump_parse_expr('2 * 3') %]
1650 Would print:
1652 [[undef, '*', 2, 3], 0];
1654 See the PLUGIN_BASE, and PLUGINS configuration items.
1656 See the documentation for Template::Manual::Plugins.
1658 "VIEW"
1660 Implement a TT style view. For more information, please see the
1661 Template::View documentation. This DIRECTIVE will correctly parse
1662 the arguments and then pass them along to a newly created
1663 Template::View object. It will fail if Template::View can not be
1664 found.
1665 "WHILE"
1667 Will process a block of code while a condition is true.
1668 [% WHILE i < 3 %]
1670 [%~ i = i + 1 %]
1671 i = [% i %]
1672 [%~ END %]
1673 Would print:
1675 i = 1
1677 i = 2
1678 i = 3
1679 You could also do:
1681 [% i = 4 %]
1683 [% WHILE (i = i - 1) %]
1684 i = [% i %]
1685 [%~ END %]
1686 Would print:
1688 i = 3
1690 i = 2
1691 i = 1
1692 Note that (f = f - 1) is a valid expression that returns the value
1694 of the assignment. The parenthesis are not optional.
1695 WHILE has a built in limit of 1000 iterations. This is controlled
1697 by the global variable $WHILE_MAX in Template::Alloy.
1698 WHILE may also be used as a post operative directive.
1700 [% "$i" WHILE (i = i + 1) < 7 %] => 123456
1702 "WRAPPER"
1704 Block directive. Processes contents of its block and then passes
1705 them in the [% content %] variable to the block or filename listed
1706 in the WRAPPER tag.
1707 [% WRAPPER foo b = 23 %]
1709 My content to be processed ([% b %]).[% a = 2 %]
1710 [% END %]
1711 [% BLOCK foo %]
1713 A header ([% a %]).
1714 [% content %]
1715 A footer ([% a %]).
1716 [% END %]
1717 This would print.
1719 A header (2).
1721 My content to be processed (23).
1722 A footer (2).
1723 The WRAPPER directive may also be used as a post operative
1725 directive.
1726 [% BLOCK baz %]([% content %])[% END -%]
1728 [% "foobar" WRAPPER baz %]
1729 Would print
1731 (foobar)');
1733 Multiple filenames can be passed by separating them with a plus, a
1735 space, or commas (TT2 doesn't support the comma). Any supplied
1736 arguments will be used on all templates. Wrappers are processed in
1737 reverse order, so that the first wrapper listed will surround each
1738 subsequent wrapper listed. Variables from inner wrappers are
1739 available to the next wrapper that surrounds it.
1740 [% WRAPPER "path/to/outer.html",
1742 "path/to/inner.html" a = "An arg" b = "Another arg" %]
1743
1745 HTML::Template templates use directives that look similar to the
1746 following:
1747 <TMPL_VAR NAME="foo">
1749 <TMPL_IF NAME="bar">
1751 BAR
1752 </TMPL_IF>
1753 The normal set of HTML::Template directives are TMPL_VAR, TMPL_IF,
1755 TMPL_ELSE, TMPL_UNLESS, TMPL_INCLUDE, and TMPL_LOOP. These tags should
1756 have either a NAME attribute, an EXPR attribute, or a bare variable
1757 name that is used to specify the value to be operated. If a NAME is
1758 specified, it may only be a single level value (as opposed to a TT
1759 chained variable). In the case of the TMPL_INCLUDE directive, the NAME
1760 is the file to be included.
1761 In Alloy, the EXPR attribute can be used with any of these types to
1763 specify TT compatible variable or expression that will be used for the
1764 value.
1765 <TMPL_VAR NAME="foo"> Prints the value contained in foo
1767 <TMPL_VAR foo> Prints the value contained in foo
1768 <TMPL_VAR EXPR="foo"> Prints the value contained in foo
1769 <TMPL_VAR NAME="foo.bar.baz"> Prints the value contained in {'foo.bar.baz'}
1771 <TMPL_VAR EXPR="foo.bar.baz"> Prints the value contained in {foo}->{bar}->{baz}
1772 <TMPL_IF foo> Prints FOO if foo is true
1774 FOO
1775 </TMPL_IF
1776 <TMPL_UNLESS foo> Prints FOO unless foo is true
1778 FOO
1779 </TMPL_UNLESS
1780 <TMPL_INCLUDE NAME="foo.ht"> Includes the template in "foo.ht"
1782 <TMPL_LOOP foo> Iterates on the arrayref foo
1784 <TMPL_VAR name>
1785 </TMPL_LOOP>
1786 Template::Alloy makes all of the other TT3 directives available in
1788 addition to the normal set of HTML::Template directives. For example,
1789 the following is valid in Alloy.
1790 <TMPL_MACRO bar(n) BLOCK>You said <TMPL_VAR n></TMPL_MACRO>
1792 <TMPL_GET bar("hello")>
1793 The TMPL_VAR tag may also include an optional ESCAPE attribute. This
1795 specifies how the value of the tag should be escaped prior to
1796 substituting into the template.
1797 Escape value | Type of escape
1799 ---------------------------------
1800 HTML, 1 | HTML encoding
1801 URL | URL encoding
1802 JS | basic javascript encoding (\n, \r, and \")
1803 NONE, 0 | No encoding (default).
1804 The TMPL_VAR tag may also include an optional DEFAULT attribute that
1806 contains a string that will be used if the variable returns false.
1807 <TMPL_VAR foo DEFAULT="Foo was false">
1809
1811 Chomping refers to the handling of whitespace immediately before and
1812 immediately after template tags. By default, nothing happens to this
1813 whitespace. Modifiers can be placed just inside the opening and just
1814 before the closing tags to control this behavior.
1815 Additionally, the PRE_CHOMP and POST_CHOMP configuration variables can
1817 be set and will globally control all chomping behavior for tags that do
1818 not have their own chomp modifier. PRE_CHOMP and POST_CHOMP can be set
1819 to any of the following values:
1820 none: 0 + Template::Constants::CHOMP_NONE
1822 one: 1 - Template::Constants::CHOMP_ONE
1823 collapse: 2 = Template::Constants::CHOMP_COLLAPSE
1824 greedy: 3 ~ Template::Constants::CHOMP_GREEDY
1825 CHOMP_NONE
1827 Don't do any chomping. The "+" sign is used to indicate
1828 CHOMP_NONE.
1829 Hello.
1831 [%+ "Hi." +%]
1833 Howdy.
1835 Would print:
1837 Hello.
1839 Hi.
1841 Howdy.
1843 CHOMP_ONE (formerly known as CHOMP_ALL)
1845 Delete any whitespace up to the adjacent newline. The "-" is used
1846 to indicate CHOMP_ONE.
1847 Hello.
1849 [%- "Hi." -%]
1851 Howdy.
1853 Would print:
1855 Hello.
1857 Hi.
1858 Howdy.
1859 CHOMP_COLLAPSE
1861 Collapse adjacent whitespace to a single space. The "=" is used to
1862 indicate CHOMP_COLLAPSE.
1863 Hello.
1865 [%= "Hi." =%]
1867 Howdy.
1869 Would print:
1871 Hello. Hi. Howdy.
1873 CHOMP_GREEDY
1875 Remove all adjacent whitespace. The "~" is used to indicate
1876 CHOMP_GREEDY.
1877 Hello.
1879 [%~ "Hi." ~%]
1881 Howdy.
1883 Would print:
1885 Hello.Hi.Howdy.
1887
1889 The following configuration variables are supported (in alphabetical
1890 order). Note: for further discussion you can refer to the TT config
1891 documentation.
1892 Items may be passed in upper or lower case. If lower case names are
1894 passed they will be resolved to uppercase during the "new" method.
1895 All of the variables in this section can be passed to the "new"
1897 constructor.
1898 my $obj = Template::Alloy->new(
1900 VARIABLES => \%hash_of_variables,
1901 AUTO_RESET => 0,
1902 TRIM => 1,
1903 POST_CHOMP => "=",
1904 PRE_CHOMP => "-",
1905 );
1906 ABSOLUTE
1908 Boolean. Default false. Are absolute paths allowed for included
1909 files.
1910 ADD_LOCAL_PATH
1912 If true, allows calls include_filename to temporarily add the
1913 directory of the current template being processed to the
1914 INCLUDE_PATHS arrayref. This allows templates to refer to files in
1915 the local template directory without specifying the local directory
1916 as part of the filename. Default is 0. If set to a negative
1917 value, the current directory will be added to the end of the
1918 current INCLUDE_PATHS.
1919 This property may also be set in the template using the CONFIG
1921 directive.
1922 [% CONFIG ADD_LOCAL_PATH => 1 %]
1924 ANYCASE
1926 Allow directive matching to be case insensitive.
1927 [% get 23 %] prints 23 with ANYCASE => 1
1929 AUTO_RESET
1931 Boolean. Default 1. Clear blocks that were set during the process
1932 method.
1933 AUTO_EVAL
1935 Boolean. Default 0 (default 1 in Velocity syntax). If set to
1936 true, double quoted strings will automatically be passed to the
1937 eval filter.
1938 BLOCKS
1940 Only available via when using the process interface.
1941 A hashref of blocks that can be used by the process method.
1943 BLOCKS => {
1945 block_1 => sub { ... }, # coderef that returns a block
1946 block_2 => 'A String', # simple string
1947 },
1948 Note that a Template::Document cannot be supplied as a value (TT
1950 supports this). However, it is possible to supply a value that is
1951 equal to the hashref returned by the load_template method.
1952 CACHE_SIZE
1954 Number of compiled templates to keep in memory. Default undef.
1955 Undefined means to allow all templates to cache. A value of 0 will
1956 force no caching. The cache mechanism will clear templates that
1957 have not been used recently.
1958 CACHE_STR_REFS
1960 Default 1. If set, any string refs will have an MD5 sum taken that
1961 will then be used for caching the document - both in memory and on
1962 the file system (if configured). This will give a significant
1963 speed boost. Note that this affects strings passed to the EVALUATE
1964 directive or eval filters as well. It may be set using the CONFIG
1965 directive.
1966 CALL_CONTEXT (Not in TT)
1968 Can be one of 'item', 'list', or 'smart'. The default type is
1969 'smart'. The CALL_CONTEXT configuration specifies in what Perl
1970 context coderefs and methods used in the processed templates will
1971 be called. TT historically has avoided the distinction of item
1972 (scalar) vs list context. To avoid worrying about this, TT
1973 introduced 'smart' context. The "@()" and "$()" context specifiers
1974 make it easier to use CALL_CONTEXT in some situations.
1975 The following table shows the relationship between the various
1977 contexts:
1978 return values smart context list context item context
1980 ------------- ------------- ------------ ------------
1981 A 'foo' 'foo' ['foo'] 'foo'
1982 B undef undef [undef] undef
1983 C (no return value) undef [] undef
1984 D (7) 7 [7] 7
1985 E (7,8,9) [7,8,9] [7,8,9] 9
1986 F @a = (7) 7 [7] 1
1987 G @a = (7,8,9) [7,8,9] [7,8,9] 3
1988 H ({b=>"c"}) {b=>"c"} [{b=>"c"}] {b=>"c"}
1989 I ([1]) [1] [[1]] [1]
1990 J ([1],[2]) [[1],[2]] [[1],[2]] [2]
1991 K [7,8,9] [7,8,9] [[7,8,9]] [7,8,9]
1992 L (undef, "foo") die "foo" [undef, "foo"] "foo"
1993 M wantarray?1:0 1 1 0
1994 Cases F, H, I and M are common sticking points of the smart context
1996 in TT2. Note that list context always returns an arrayref from a
1997 method or function call. Smart context can give confusing results
1998 sometimes, especially the I and J cases. Case L for smart match is
1999 very surprising.
2000 The list and item context provide another feature for method calls.
2002 In smart context, TT will look for a hash key in the object by the
2003 same name as the method, if a method by that name doesn't exist.
2004 In item and list context Alloy will die if a method by that name
2005 cannot be found.
2006 The CALL_CONTEXT configuration item can be passed to new or it may
2008 also be set during runtime using the CONFIG directive. The
2009 following method call would be in list context:
2010 [% CONFIG CALL_CONTEXT => 'list';
2012 results = my_obj.get_results;
2013 CONFIG CALL_CONTEXT => 'smart'
2014 %]
2015 Note that we needed to restore CALL_CONTEXT to the default 'smart'
2017 value. Template::Alloy has added the "@()" (list) and the "$()"
2018 (item) context specifiers. The previous example could be written
2019 as:
2020 [% results = @( my_obj.get_results ) %]
2022 To call that same method in item (scalar) context you would do the
2024 following:
2025 [% results = $( my_obj.get_results ) %]
2027 The "@()" and "$()" operators are based on the Perl 6 counterpart.
2029 COMPILE_DIR
2031 Base directory to store compiled templates. Default undef.
2032 Compiled templates will only be stored if one of COMPILE_DIR and
2033 COMPILE_EXT is set.
2034 If set, the AST of parsed documents will be cached. If
2036 COMPILE_PERL is set, the compiled perl code will also be stored.
2037 COMPILE_EXT
2039 Extension to add to stored compiled template filenames. Default
2040 undef.
2041 If set, the AST of parsed documents will be cached. If
2043 COMPILE_PERL is set, the compiled perl code will also be stored.
2044 COMPILE_PERL
2046 Default false.
2047 If set to 1 or 2, will translate the normal AST into a perl 5 code
2049 document. This document can then be executed directly, cached in
2050 memory, or cached on the file system depending upon the
2051 configuration items set.
2052 If set to 1, a perl code document will always be generated.
2054 If set to 2, a perl code document will only be generated if an AST
2056 has already been cached for the document. This should give a speed
2057 benefit and avoid extra compilation unless the document has been
2058 used more than once.
2059 If Alloy is running in a cached environment such as mod_perl, then
2061 using compile_perl can offer some speed benefit and makes Alloy
2062 faster than Text::Tmpl and as fast as HTML::Template::Compiled (but
2063 Alloy has more features).
2064 If you are not running in a cached environment, such as from
2066 commandline, or from CGI, it is generally faster to only run from
2067 the AST (with COMPILE_PERL => 0).
2068 CONSTANTS
2070 Hashref. Used to define variables that will be "folded" into the
2071 compiled template. Variables defined here cannot be overridden.
2072 CONSTANTS => {my_constant => 42},
2074 A template containing:
2076 [% constants.my_constant %]
2078 Will have the value 42 compiled in.
2080 Constants defined in this way can be chained as in [%
2082 constant.foo.bar.baz %].
2083 CONSTANT_NAMESPACE
2085 Allow for setting the top level of values passed in CONSTANTS.
2086 Default value is 'constants'.
2087 DEBUG
2089 Takes a list of constants |'ed together which enables different
2090 debugging modes. Alternately the lowercase names may be used
2091 (multiple values joined by a ",").
2092 The only supported TT values are:
2094 DEBUG_UNDEF (2) - debug when an undefined value is used.
2095 DEBUG_DIRS (8) - debug when a directive is used.
2096 DEBUG_ALL (2047) - turn on all debugging.
2097 Either of the following would turn on undef and directive debugging:
2099 DEBUG => 'undef, dirs', # preferred
2101 DEBUG => 2 | 8,
2102 DEBUG => DEBUG_UNDEF | DEBUG_DIRS, # constants from Template::Constants
2103 DEBUG_FORMAT
2105 Change the format of messages inserted when DEBUG has DEBUG_DIRS
2106 set on. This essentially the same thing as setting the format
2107 using the DEBUG directive.
2108 DEFAULT
2110 The name of a default template file to use if the passed one is not
2111 found.
2112 DELIMITER
2114 String to use to split INCLUDE_PATH with. Default is :. It is
2115 more straight forward to just send INCLUDE_PATH an arrayref of
2116 paths.
2117 DUMP
2119 Configures the behavior of the DUMP tag. May be set to 0, a
2120 hashref, or another true value. Default is true.
2121 If set to 0, all DUMP directives will do nothing. This is useful
2123 if you would like to turn off the DUMP directives under some
2124 environments.
2125 IF set to a true value (or undefined) then DUMP directives will
2127 operate.
2128 If set to a hashref, the values of the hash can be used to
2130 configure the operation of the DUMP directives. The following are
2131 the values that can be set in this hash.
2132 EntireStash
2134 Default 1. If set to 0, then the DUMP directive will not print
2135 the entire contents of the stash when a DUMP directive is
2136 called without arguments.
2137 handler
2139 Defaults to an internal coderef. If set to a coderef, the DUMP
2140 directive will pass the arguments to be dumped and expects a
2141 string with the dumped data. This gives complete control over
2142 the dump process.
2143 Note 1: The default handler makes sure that values matching the
2145 private variable regex are not included. If you install your
2146 own handler, you will need to take care of these variables if
2147 you intend for them to not be shown.
2148 Note 2: If you would like the name of the variable to be
2150 dumped, include the string '$VAR1' and the DUMP directive will
2151 interpolate the value. For example, to dump all output as YAML
2152 - you could do the following:
2153 DUMP => {
2155 handler => sub {
2156 require YAML;
2157 return "\$VAR1 =\n".YAML::Dump(shift);
2158 },
2159 }
2160 header
2162 Default 1. Controls whether a header is printed for each DUMP
2163 directive. The header contains the file and line number the
2164 DUMP directive was called from. If set to 0 the headers are
2165 disabled.
2166 html
2168 Defaults to 1 if $ENV{'REQUEST_METHOD'} is set - 0 otherwise.
2169 If set to 1, then the output of the DUMP directive is passed to
2170 the html filter and encased in "pre" tags. If set to 0 no html
2171 encoding takes place.
2172 Sortkeys, Useqq, Ident, Pad, etc
2174 Any of the Data::Dumper configuration items may be passed.
2175 ENCODING
2177 Default undef. If set, and if Perl version is greater than or
2178 equal to 5.7.3 (when Encode.pm was first included), then
2179 Encode::decode will be called everytime a template file is
2180 processed and will be passed the value of ENCODING and text from
2181 the template.
2182 This item can also be set using [% CONFIG ENCODING => encoding %]
2184 before calling INCLUDE or PROCESS directives to change encodings on
2185 the fly.
2186 END_TAG
2188 Set a string to use as the closing delimiter for TT. Default is
2189 "%]".
2190 ERROR
2192 Used as a fall back when the processing of a template fails. May
2193 either be a single filename that will be used in all cases, or may
2194 be a hashref of options where the keynames represent error types
2195 that will be handled by the filename in their value. A key named
2196 default will be used if no other matching keyname can be found.
2197 The selection process is similar to that of the TRY/CATCH/THROW
2198 directives (see those directives for more information).
2199 my $t = Template::Alloy->new({
2201 ERROR => 'general/catch_all_errors.html',
2202 });
2203 my $t = Template::Alloy->new({
2205 ERROR => {
2206 default => 'general/catch_all_errors.html',
2207 foo => 'catch_all_general_foo_errors.html',
2208 'foo.bar' => 'catch_foo_bar_errors.html',
2209 },
2210 });
2211 Note that the ERROR handler will only be used for errors during the
2213 processing of the main document. It will not catch errors that
2214 occur in templates found in the PRE_PROCESS, POST_PROCESS, and
2215 WRAPPER configuration items.
2216 ERRORS
2218 Same as the ERROR configuration item. Both may be used
2219 interchangably.
2220 EVAL_PERL
2222 Boolean. Default false. If set to a true value, PERL and RAWPERL
2223 blocks will be allowed to run. This is a potential security hole,
2224 as arbitrary perl can be included in the template. If
2225 Template::Toolkit is installed, a true EVAL_PERL value also allows
2226 the perl and evalperl filters to be used.
2227 FILTERS
2229 Allow for passing in TT style filters.
2230 my $filters = {
2232 filter1 => sub { my $str = shift; $s =~ s/./1/gs; $s },
2233 filter2 => [sub { my $str = shift; $s =~ s/./2/gs; $s }, 0],
2234 filter3 => [sub { my ($context, @args) = @_; return sub { my $s = shift; $s =~ s/./3/gs; $s } }, 1],
2235 };
2236 my $str = q{
2238 [% a = "Hello" %]
2239 1 ([% a | filter1 %])
2240 2 ([% a | filter2 %])
2241 3 ([% a | filter3 %])
2242 };
2243 my $obj = Template::Alloy->new(FILTERS => $filters);
2245 $obj->process(\$str) || die $obj->error;
2246 Would print:
2248 1 (11111)
2250 2 (22222)
2251 3 (33333)
2252 Filters passed in as an arrayref should contain a coderef and a
2254 value indicating if they are dynamic or static (true meaning
2255 dynamic). The dynamic filters are passed the pseudo context object
2256 and any arguments and should return a coderef that will be called
2257 as the filter. The filter coderef is then passed the string.
2258 GLOBAL_CACHE
2260 Default 0. If true, documents will be cached in
2261 $Template::Alloy::GLOBAL_CACHE. It may also be passed a hashref,
2262 in which case the documents will be cached in the passed hashref.
2263 The TT, Tmpl, and velocity will automatically cache documents in
2265 the object. The HTML::Template interface uses a new object each
2266 time. Setting the HTML::Template's CACHE configuration is the same
2267 as setting GLOBAL_CACHE.
2268 INCLUDE_PATH
2270 A string or an arrayref or coderef that returns an arrayref that
2271 contains directories to look for files included by processed
2272 templates. Defaults to "." (the current directory).
2273 INCLUDE_PATHS
2275 Non-TT item. Same as INCLUDE_PATH but only takes an arrayref. If
2276 not specified then INCLUDE_PATH is turned into an arrayref and
2277 stored in INCLUDE_PATHS. Overrides INCLUDE_PATH.
2278 INTERPOLATE
2280 Boolean. Specifies whether variables in text portions of the
2281 template will be interpolated. For example, the $variable and
2282 ${var.value} would be substituted with the appropriate values from
2283 the variable cache (if INTERPOLATE is on).
2284 [% IF 1 %]The variable $variable had a value ${var.value}[% END %]
2286 LOAD_PERL
2288 Indicates if the USE directive can fall back and try and load a
2289 perl module if the indicated module was not found in the
2290 PLUGIN_BASE path. See the USE directive. This configuration has
2291 no bearing on the COMPILE_PERL directive used to indicate using
2292 compiled perl documents.
2293 MAX_EVAL_RECURSE (Alloy only)
2295 Will use $Template::Alloy::MAX_EVAL_RECURSE if not present.
2296 Default is 50. Prevents runaway on the following:
2297 [% f = "[% f|eval %]" %][% f|eval %]
2299 MAX_MACRO_RECURSE (Alloy only)
2301 Will use $Template::Alloy::MAX_MACRO_RECURSE if not present.
2302 Default is 50. Prevents runaway on the following:
2303 [% MACRO f BLOCK %][% f %][% END %][% f %]
2305 NAMESPACE
2307 No Template::Namespace::Constants support. Hashref of hashrefs
2308 representing constants that will be folded into the template at
2309 compile time.
2310 Template::Alloy->new(NAMESPACE => {constants => {
2312 foo => 'bar',
2313 }});
2314 Is the same as
2316 Template::Alloy->new(CONSTANTS => {
2318 foo => 'bar',
2319 });
2320 Any number of hashes can be added to the NAMESPACE hash.
2322 NEGATIVE_STAT_TTL (Not in TT)
2324 Defaults to STAT_TTL which defaults to $STAT_TTL which defaults to
2325 1.
2326 Similar to STAT_TTL - but represents the time-to-live seconds until
2328 a document that was not found is checked again against the system
2329 for modifications. Setting this number higher will allow for fewer
2330 file system accesses. Setting it to a negative number will allow
2331 for the file system to be checked every hit.
2332 NO_INCLUDES
2334 Default false. If true, calls to INCLUDE, PROCESS, WRAPPER and
2335 INSERT will fail. This option is also available when using the
2336 process method.
2337 OUTPUT
2339 Alternate way of passing in the output location for processed
2340 templates. If process is not passed an output argument, it will
2341 look for this value.
2342 See the process method for a listing of possible values.
2344 OUTPUT_PATH
2346 Base path for files written out via the process method or via the
2347 redirect and file filters. See the redirect virtual method and the
2348 process method for more information.
2349 PLUGINS
2351 A hashref of mappings of plugin modules.
2352 PLUGINS => {
2354 Iterator => 'Template::Plugin::Iterator',
2355 DBI => 'MyDBI',
2356 },
2357 See the USE directive for more information.
2359 PLUGIN_BASE
2361 Default value is Template::Plugin. The base module namespace that
2362 template plugins will be looked for. See the USE directive for
2363 more information. May be either a single namespace, or an arrayref
2364 of namespaces.
2365 POST_CHOMP
2367 Set the type of chomping at the ending of a tag. See the section
2368 on chomping for more information.
2369 POST_PROCESS
2371 Only available via when using the process interface.
2372 A list of templates to be processed and appended to the content
2374 after the main template. During this processing the "template"
2375 namespace will contain the name of the main file being processed.
2376 This is useful for adding a global footer to all templates.
2378 PRE_CHOMP
2380 Set the type of chomping at the beginning of a tag. See the
2381 section on chomping for more information.
2382 PRE_DEFINE
2384 Same as the VARIABLES configuration item.
2385 PRE_PROCESS
2387 Only available via when using the process interface.
2388 A list of templates to be processed before and pre-pended to the
2390 content before the main template. During this processing the
2391 "template" namespace will contain the name of the main file being
2392 processed.
2393 This is useful for adding a global header to all templates.
2395 PROCESS
2397 Only available via when using the process interface.
2398 Specify a file to use as the template rather than the one passed in
2400 to the ->process method.
2401 RECURSION
2403 Boolean. Default false. Indicates that INCLUDED or PROCESSED
2404 files can refer to each other in a circular manner. Be careful
2405 about recursion.
2406 RELATIVE
2408 Boolean. Default false. If true, allows filenames to be specified
2409 that are relative to the currently running process.
2410 SEMICOLONS
2412 Boolean. Default fast. If true, then the syntax will require that
2413 semi-colons separate multiple directives in the same tag. This is
2414 useful for keeping the syntax a little more clean as well as
2415 trouble shooting some errors.
2416 SHOW_UNDEFINED_INTERP (Not in TT)
2418 Default false (default true in Velocity). If INTERPOLATE is true,
2419 interpolated dollar variables that return undef will be removed.
2420 With SHOW_UNDEFINED_INTERP set, undef values will leave the
2421 variable there.
2422 [% CONFIG INTERPOLATE => 1 %]
2424 [% SET foo = 1 %][% SET bar %]
2425 ($foo)($bar) ($!foo)($!bar)
2426 Would print:
2428 (1)() (1)()
2430 But the following:
2432 [% CONFIG INTERPOLATE => 1, SHOW_UNDEFINED_INTERP => 1 %]
2434 [% SET foo = 1 %][% SET bar %]
2435 ($foo)($bar) ($!foo)($!bar)
2436 Would print:
2438 (1)($bar) (1)()
2440 Note that you can use an exclamation point directly after the the
2442 dollar to make the variable silent. This is similar to how
2443 Velocity works.
2444 START_TAG
2446 Set a string or regular expression to use as the opening delimiter
2447 for TT. Default is "[%". You should be sure that the tag does not
2448 include grouping parens or INTERPOLATE will not function properly.
2449 STASH
2451 Template::Alloy manages its own stash of variables. You can pass a
2452 Template::Stash or Template::Stash::XS object, but Template::Alloy
2453 will copy all of values out of the object into its own stash.
2454 Template::Alloy won't use any of the methods of the passed STASH
2455 object. The STASH option is only available when using the process
2456 method.
2457 STAT_TTL
2459 Defaults to $STAT_TTL which defaults to 1. Represents time-to-live
2460 seconds until a cached in memory document is compared to the file
2461 system for modifications. Setting this number higher will allow
2462 for fewer file system accesses. Setting it to a negative number
2463 will allow for the file system to be checked every hit.
2464 STREAM
2466 Defaults to false. If set to true, generated template content will
2467 be printed to the currently selected filehandle (default is STDOUT)
2468 as soon as it is ready - there will be no buffering of the output.
2469 The Stream role uses the Play role's directives
2471 (non-compiled_perl).
2472 All directives and configuration work, except for the following
2474 exceptions:
2475 CLEAR directive
2477 Because the output is not buffered - the CLEAR directive would
2478 have no effect. The CLEAR directive will throw an error when
2479 STREAM is on.
2480 TRIM configuration
2482 Because the output is not buffered - trim operations cannot be
2483 played on the output buffers.
2484 WRAPPER configuration/directive
2486 The WRAPPER configuration and directive items effectively turn
2487 off STREAM since the WRAPPERS are generated in reverse order
2488 and because the content is inserted into the middle of the
2489 WRAPPERS. WRAPPERS will still work, they just won't stream.
2490 VARIOUS errors
2492 Because the template is streaming, items that cause errors my
2493 result in partially printed pages - since the error would occur
2494 part way through the print.
2495 All output is printed directly to the currently selected filehandle
2497 (defaults to STDOUT) via the CORE::print function. Any output
2498 parameter passed to process or process_simple will be ignored.
2499 If you would like the output to go to another handle, you will need
2501 to select that handle, process the template, and re-select STDOUT.
2502 SYNTAX (not in TT)
2504 Defaults to "cet". Indicates the syntax that will be used for
2505 parsing included templates or eval'ed strings. You can use the
2506 CONFIG directive to change the SYNTAX on the fly (it will not
2507 affect the syntax of the document currently being parsed).
2508 The syntax may be passed in upper or lower case.
2510 The available choices are:
2512 alloy - Template::Alloy style - the same as TT3
2514 tt3 - Template::Toolkit ver3 - same as Alloy
2515 tt2 - Template::Toolkit ver2 - almost the same as TT3
2516 tt1 - Template::Toolkit ver1 - almost the same as TT2
2517 ht - HTML::Template - same as HTML::Template::Expr without EXPR
2518 hte - HTML::Template::Expr
2519 Passing in a different syntax allows for the process method to use
2521 a non-TT syntax and for the output method to use a non-HT syntax.
2522 The following is a sample of HTML::Template interface usage parsing
2524 a Template::Toolkit style document.
2525 my $obj = Template::Alloy->new(filename => 'my/template.tt'
2527 syntax => 'cet');
2528 $obj->param(\%swap);
2529 print $obj->output;
2530 The following is a sample of Template::Toolkit interface usage
2532 parsing a HTML::Template::Expr style document.
2533 my $obj = Template::Alloy->new(SYNTAX => 'hte');
2535 $obj->process('my/template.ht', \%swap);
2536 You can use the define_syntax method to add another custom syntax
2538 to the list of available options.
2539 TAG_STYLE
2541 Allow for setting the type of tag delimiters to use for parsing the
2542 TT. See the TAGS directive for a listing of the available types.
2543 TRIM
2545 Remove leading and trailing whitespace from blocks and templates.
2546 This operation is performed after all enclosed template tags have
2547 been executed.
2548 UNDEFINED_ANY
2550 This is not a TT configuration option. This option expects to be a
2551 code ref that will be called if a variable is undefined during a
2552 call to play_expr. It is passed the variable identity array as a
2553 single argument. This is most similar to the "undefined" method of
2554 Template::Stash. It allows for the "auto-defining" of a variable
2555 for use in the template. It is suggested that UNDEFINED_GET be
2556 used instead as UNDEFINED_ANY is a little to general in defining
2557 variables.
2558 You can also sub class the module and override the undefined_any
2560 method.
2561 UNDEFINED_GET
2563 This is not a TT configuration option. This option expects to be a
2564 code ref that will be called if a variable is undefined during a
2565 call to GET. It is passed the variable identity array as a single
2566 argument. This is more useful than UNDEFINED_ANY in that it is
2567 only called during a GET directive rather than in embedded
2568 expressions (such as [% a || b || c %]).
2569 You can also sub class the module and override the undefined_get
2571 method.
2572 V1DOLLAR
2574 This allows for some compatibility with TT1 templates. The only
2575 real behavior change is that [% $foo %] becomes the same as [% foo
2576 %]. The following is a basic table of changes invoked by using
2577 V1DOLLAR.
2578 With V1DOLLAR Equivalent Without V1DOLLAR (Normal default)
2580 "[% foo %]" "[% foo %]"
2581 "[% $foo %]" "[% foo %]"
2582 "[% ${foo} %]" "[% ${foo} %]"
2583 "[% foo.$bar %]" "[% foo.bar %]"
2584 "[% ${foo.bar} %]" "[% ${foo.bar} %]"
2585 "[% ${foo.$bar} %]" "[% ${foo.bar} %]"
2586 "Text: $foo" "Text: $foo"
2587 "Text: ${foo}" "Text: ${foo}"
2588 "Text: ${$foo}" "Text: ${foo}"
2589 V2EQUALS
2591 Default 1 in TT syntaxes, defaults to 0 in HTML::Template syntaxes.
2592 If set to 1 then "==" is an alias for "eq" and "!= is an alias for
2594 "ne".
2595 [% CONFIG V2EQUALS => 1 %][% ('7' == '7.0') || 0 %]
2597 [% CONFIG V2EQUALS => 0 %][% ('7' == '7.0') || 0 %]
2598 Prints
2600 0
2602 1
2603 V2PIPE
2605 Restores the behavior of the pipe operator to be compatible with
2606 TT2.
2607 With V2PIPE = 1
2609 [%- BLOCK a %]b is [% b %]
2611 [% END %]
2612 [%- PROCESS a b => 237 | repeat(2) %]
2613 # output of block "a" with b set to 237 is passed to the repeat(2) filter
2615 b is 237
2617 b is 237
2618 With V2PIPE = 0 (default)
2620 [%- BLOCK a %]b is [% b %]
2622 [% END %]
2623 [% PROCESS a b => 237 | repeat(2) %]
2624 # b set to 237 repeated twice, and b passed to block "a"
2626 b is 237237
2628 VARIABLES
2630 A hashref of variables to initialize the template stash with.
2631 These variables are available for use in any of the executed
2632 templates. See the section on VARIABLES for the types of
2633 information that can be passed in.
2634 VMETHOD_FUNCTIONS
2636 Defaults to 1. All scalar virtual methods are available as top
2637 level functions as well. This is not true of TT2. In
2638 Template::Alloy the following are equivalent:
2639 [% "abc".length %]
2641 [% length("abc") %]
2642 You may set VMETHOD_FUNCTIONS to 0 to disable this behavior.
2644 WRAPPER
2646 Only available via when using the process interface.
2647 Operates similar to the WRAPPER directive. The option can be given
2649 a single filename, or an arrayref of filenames that will be used to
2650 wrap the processed content. If an arrayref is passed the filenames
2651 are processed in reverse order, so that the first filename
2652 specified will end up being on the outside (surrounding all other
2653 wrappers).
2654 my $t = Template::Alloy->new(
2656 WRAPPER => ['my/wrappers/outer.html', 'my/wrappers/inner.html'],
2657 );
2658 Content generated by the PRE_PROCESS and POST_PROCESS will come
2660 before and after (respectively) the content generated by the
2661 WRAPPER configuration item.
2662 See the WRAPPER direcive for more examples of how wrappers are
2664 construted.
2665
2667 The following HTML::Template and HTML::Template::Expr configuration
2668 variables are supported (in HTML::Template documentation order). Note:
2669 for further discussion you can refer to the HT documentation. Many of
2670 the variables mentioned in the TT CONFIGURATION section apply here as
2671 well. Unless noted, these items only apply when using the output
2672 method.
2673 Items may be passed in upper or lower case. All passed items are
2675 resolved to upper case.
2676 These variables should be passed to the "new" constructor.
2678 my $obj = Template::Alloy->new(
2680 type => 'filename',
2681 source => 'my/template.ht',
2682 die_on_bad_params => 1,
2683 loop_context_vars => 1,
2684 global_vars => 1
2685 post_chomp => "=",
2686 pre_chomp => "-",
2687 );
2688 TYPE
2690 Can be one of filename, filehandle, arrayref, or scalarref.
2691 Indicates what type of input is in the "source" configuration item.
2692 SOURCE
2694 Stores where to read the input file. The type is specified in the
2695 "type" configuration item.
2696 FILENAME
2698 Indicates a filename to read the template from. Same as putting
2699 the filename in the "source" item and setting "type" to "filename".
2700 Must be set to enable caching.
2702 FILEHANDLE
2704 Should contain an open filehandle to read the template from. Same
2705 as putting the filehandle in the "source" item and setting "type"
2706 to "filehandle".
2707 Will not be cached.
2709 ARRAYREF
2711 Should contain an arrayref whose values are the lines of the
2712 template. Same as putting the arrayref in the "source" item and
2713 setting "type" to "arrayref".
2714 Will not be cached.
2716 SCALARREF
2718 Should contain an reference to a scalar that contains the template.
2719 Same as putting the scalar ref in the "source" item and setting
2720 "type" to "scalarref".
2721 Will not be cached.
2723 CACHE
2725 If set to one, then Alloy will use a global, in-memory document
2726 cache to store compiled templates in between calls. This is
2727 generally only useful in a mod_perl environment. The document is
2728 checked for a different modification time at each request.
2729 BLIND_CACHE
2731 Same as with cache enabled, but will not check if the document has
2732 been modified.
2733 FILE_CACHE
2735 If set to 1, will cache the compiled document on the file system.
2736 If true, file_cache_dir must be set.
2737 FILE_CACHE_DIR
2739 The directory where to store cached documents when file_cache is
2740 true. This is similar to the TT compile_dir option.
2741 DOUBLE_FILE_CACHE
2743 Uses a combination of file_cache and cache.
2744 PATH
2746 Same as INCLUDE_PATH when using the process method.
2747 ASSOCIATE
2749 May be a single CGI object or an arrayref of objects. The params
2750 from these objects will be added to the params during the output
2751 call.
2752 CASE_SENSITIVE
2754 Allow passed variables set through the param method, or the
2755 associate configuration to be used case sensitively. Default is
2756 off. It is highly suggested that this be set to 1.
2757 LOOP_CONTEXT_VARS
2759 Default false. When true, calls to the loop directive will create
2760 the following variables that give information about the current
2761 iteration of the loop:
2762 __first__ - True on first iteration only
2764 __last__ - True on last iteration only
2765 __inner__ - True on any iteration that isn't first or last
2766 __odd__ - True on odd iterations
2767 __counter__ - The iteration count
2768 These variables are also available to LOOPs run under TT syntax if
2770 loop_context_vars is set and if QR_PRIVATE is set to 0.
2771 GLOBAL_VARS.
2773 Default true in HTE mode. Default false in HT. Allows top level
2774 variables to be used in LOOPs. When false, only variables defined
2775 in the current LOOP iteration hashref will be available.
2776 DEFAULT_ESCAPE
2778 Controls the type of escape used on named variables in TMPL_VAR
2779 directives. Can be one of HTML, URL, or JS. The values of
2780 TMPL_VAR directives will be encoded with this type unless they
2781 specify their own type via an ESCAPE attribute.
2782 NO_TT
2784 Default false in 'hte' syntax. Default true in 'ht' syntax. If
2785 true, no extended TT directives will be allowed.
2786 The output method uses 'hte' syntax by default.
2788
2790 The following list of methods are other interesting methods of Alloy
2791 that may be re-implemented by subclasses of Alloy.
2792 "exception"
2794 Creates an exception object blessed into the package listed in
2795 Template::Alloy::Exception.
2796 "execute_tree"
2798 Executes a parsed tree (returned from parse_tree)
2799 "play_expr"
2801 Play the parsed expression. Turns a variable identity array into
2802 the parsed variable. This method is also responsible for playing
2803 operators and running virtual methods and filters. The variable
2804 identity array may also contain literal values, or operator
2805 identity arrays.
2806 "include_filename"
2808 Takes a file path, and resolves it into the full filename using
2809 paths from INCLUDE_PATH or INCLUDE_PATHS.
2810 "_insert"
2812 Resolves the file passed, and then returns its contents.
2813 "list_filters"
2815 Dynamically loads the filters list from Template::Filters when a
2816 filter is used that is not natively implemented in Alloy.
2817 "load_template"
2819 Given a filename or a string reference will return a "document"
2820 hashref hash that contains the parsed tree.
2821 my $doc = $self->load_template($file); # errors die
2823 This method handles the in-memory caching of the document.
2825 "load_tree"
2827 Given the "document" hashref, will either load the parsed AST from
2828 file (if configured to do so), or will load the content, parse the
2829 content using the Parse role, and will return the tree. File based
2830 caching of the parsed AST happens here.
2831 "load_perl"
2833 Only used if COMPILE_PERL is true (default is false).
2834 Given the "document" hashref, will either load the compiled perl
2836 from file (if configured to do so), or will load the AST using
2837 "load_tree", will compile a new perl code document using the
2838 Compile role, and will return the perl code. File based caching of
2839 the compiled perl happens here.
2840 "parse_tree"
2842 Parses the passed string ref with the appopriate template syntax.
2843 See Template::Alloy::Parse for more details.
2845 "parse_expr"
2847 Parses the passed string ref for a variable or expression.
2848 See Template::Alloy::Parse for more details.
2850 "parse_args"
2852 See Template::Alloy::Parse for more details.
2853 "set_variable"
2855 Used to set a variable. Expects a variable identity array and the
2856 value to set. It will autovifiy as necessary.
2857 "throw"
2859 Creates an exception object from the arguments and dies.
2860 "undefined_any"
2862 Called during play_expr if a value is returned that is undefined.
2863 This could be used to magically create variables on the fly. This
2864 is similar to Template::Stash::undefined. It is suggested that
2865 undefined_get be used instead. Default behavior returns undef.
2866 You may also pass a coderef via the UNDEFINED_ANY configuration
2867 variable. Also, you can try using the DEBUG => 'undef',
2868 configuration option which will throw an error on undefined
2869 variables.
2870 "undefined_get"
2872 Called when a variable is undefined during a GET directive. This
2873 is useful to see if a value that is about to get inserted into the
2874 text is undefined. undefined_any is a little too general for most
2875 cases. Also, you may pass a coderef via the UNDEFINED_GET
2876 configuration variable.
2877
2879 The following is a brief list of other methods used by Alloy.
2880 Generally, these shouldn't be overwritten by subclasses.
2881 "context"
2883 Used to create a "pseudo" context object that allows for
2884 portability of TT plugins, filters, and perl blocks that need a
2885 context object. Uses the Template::Alloy::Context class.
2886 "debug_node"
2888 Used to get debug info on a directive if DEBUG_DIRS is set.
2889 "get_line_number_by_index"
2891 Used to turn string index position into line number
2892 "interpolate_node"
2894 Used for parsing text nodes for dollar variables when interpolate
2895 is on.
2896 "play_operator"
2898 Provided by the Operator role. Allows for playing an operator AST.
2899 See Template::Alloy::Operator for more details.
2901 "apply_precedence"
2903 Provided by the Parse role. Allows for parsed operator array to be
2904 translated to a tree based upon operator precedence.
2905 "_process"
2907 Called by process and the PROCESS, INCLUDE and other directives.
2908 "slurp"
2910 Reads contents of passed filename - throws file exception on error.
2911 "split_paths"
2913 Used to split INCLUDE_PATH or other directives if an arrayref is
2914 not passed.
2915 "_vars"
2917 Return a reference to the current stash of variables. This is
2918 currently only used by the pseudo context object and may disappear
2919 at some point.
2920
2922 Thanks to Andy Wardley for creating Template::Toolkit.
2923 Thanks to Sam Tregar for creating HTML::Template.
2925 Thanks to David Lowe for creating Text::Tmpl.
2927 Thanks to the Apache Velocity guys.
2929 Thanks to Ben Grimm for a patch to allow passing a parsed document to
2931 the ->process method.
2932 Thanks to David Warring for finding a parse error in HTE syntax.
2934 Thanks to Carl Franks for adding the base ENCODING support.
2936
2938 Paul Seamons <paul at seamons dot com>
2939
2941 This module may be distributed under the same terms as Perl itself.
2942
2944 Hey! The above document had some coding errors, which are explained
2945 below:
2946 Around line 834:
2948 You forgot a '=back' before '=head1'
2949 Around line 1942:
2951 You forgot a '=back' before '=head1'
2952perl v5.12.0 2008-09-17 Template::Alloy(3)