1Template::Alloy::TT(3)User Contributed Perl DocumentationTemplate::Alloy::TT(3)
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6 Template::Alloy::TT - Template::Toolkit role
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9 The Template::Alloy::TT role provides the syntax and the interface for
10 Template::Toolkit version 1, 2, and 3. It also brings many of the fea‐
11 tures from the various templating systems.
12 And it is fast.
14 See the Template::Alloy documentation for configuration and other
16 parameters.
17
19 Alloy uses the same base template syntax and configuration items as
20 TT2, but the internals of Alloy were written from scratch. Addition‐
21 ally much of the planned TT3 syntax is supported as well as most of
22 that of HTML::Template::Expr. The following is a list of some of the
23 ways that the configuration and syntax of Alloy are different from that
24 of TT2. Note: items that are planned to work in TT3 are marked with
25 (TT3).
26 · Numerical hash keys work
28 [% a = {1 => 2} %]
30 · Quoted hash key interpolation is fine
32 [% a = {"$foo" => 1} %]
34 · Multiple ranges in same constructor
36 [% a = [1..10, 21..30] %]
38 · Constructor types can call virtual methods. (TT3)
40 [% a = [1..10].reverse %]
42 [% "$foo".length %]
44 [% 123.length %] # = 3
46 [% 123.4.length %] # = 5
48 [% -123.4.length %] # = -5 ("." binds more tightly than "-")
50 [% (a ~ b).length %]
52 [% "hi".repeat(3) %] # = hihihi
54 [% {a => b}.size %] # = 1
56 · The "${" and "}" variable interpolators can contain expressions,
58 not just variables.
59 [% [0..10].${ 1 + 2 } %] # = 4
61 [% {ab => 'AB'}.${ 'a' ~ 'b' } %] # = AB
63 [% color = qw/Red Blue/; FOR [1..4] ; color.${ loop.index % color.size } ; END %]
65 # = RedBlueRedBlue
66 · You can use regular expression quoting.
68 [% "foo".match( /(F\w+)/i ).0 %] # = foo
70 · Tags can be nested.
72 [% f = "[% (1 + 2) %]" %][% f⎪eval %] # = 3
74 · Arrays can be accessed with non-integer numbers.
76 [% [0..10].${ 2.3 } %] # = 3
78 · Reserved names are less reserved. (TT3)
80 [% GET GET %] # gets the variable named "GET"
82 [% GET $GET %] # gets the variable who's name is stored in "GET"
84 · Filters and SCALAR_OPS are interchangeable. (TT3)
86 [% a ⎪ length %]
88 [% b . lower %]
90 · Pipe "⎪" can be used anywhere dot "." can be and means to call the
92 virtual method. (TT3)
93 [% a = {size => "foo"} %][% a.size %] # = foo
95 [% a = {size => "foo"} %][% a⎪size %] # = 1 (size of hash)
97 · Pipe "⎪" and "." can be mixed. (TT3)
99 [% "aa" ⎪ repeat(2) . length %] # = 4
101 · Added V2PIPE configuration item
103 Restores the behavior of the pipe operator to be compatible with
105 TT2.
106 With V2PIPE = 1
108 [% PROCESS a ⎪ repeat(2) %] # = value of block or file a repeated twice
110 With V2PIPE = 0 (default)
112 [% PROCESS a ⎪ repeat(2) %] # = process block or file named a ~ a
114 · Added V2EQUALS configuration item
116 Allows for turning off TT2 "==" behavior. Defaults to 1 in TT syn‐
118 taxes and to 0 in HT syntaxes.
119 [% CONFIG V2EQUALS => 1 %][% ('7' == '7.0') ⎪⎪ 0 %]
121 [% CONFIG V2EQUALS => 0 %][% ('7' == '7.0') ⎪⎪ 0 %]
122 Prints
124 0
126 1
127 · Added AUTO_EVAL configuration item.
129 Default false. If true, will automatically call eval filter on
131 double quoted strings.
132 · Added SHOW_UNDEFINED_INTERP configuration item.
134 Default false. If true, will leave in place interpolated values
136 that weren't defined. You can then use the Velocity notation $!foo
137 to not show these values.
138 · Added Virtual Object Namespaces. (TT3)
140 The Text, List, and Hash types give direct access to virtual meth‐
142 ods.
143 [% a = "foobar" %][% Text.length(a) %] # = 6
145 [% a = [1 .. 10] %][% List.size(a) %] # = 10
147 [% a = {a=>"A", b=>"B"} ; Hash.size(a) %] = 2
149 [% foo = {a => 1, b => 2}
151 ⎪ Hash.keys
152 ⎪ List.join(", ") %] # = a, b
153 · Added "fmt" scalar, list, and hash virtual methods.
155 [% list.fmt("%s", ", ") %]
157 [% hash.fmt("%s => %s", "\n") %]
159 · Added missing HTML::Template::Expr vmethods
161 The following vmethods were added - they correspond to the perl
163 functions of the same name.
164 abs
166 atan2
167 cos
168 exp
169 hex
170 lc
171 log
172 oct
173 sin
174 sprintf
175 sqrt
176 srand
177 uc
178 · Allow all Scalar vmethods to behave as top level functions.
180 [% sprintf("%d %d", 7, 8) %] # = "7 8"
182 The following are equivalent in Alloy:
184 [% "abc".length %]
186 [% length("abc") %]
187 This feature may be disabling by setting the VMETHOD_FUNCTIONS con‐
189 figuration item to 0.
190 This is similar to how HTML::Template::Expr operates, but now you
192 can use this functionality in TT templates as well.
193 · Whitespace is less meaningful. (TT3)
195 [% 2-1 %] # = 1 (fails in TT2)
197 · Added pow operator.
199 [% 2 ** 3 %] [% 2 pow 3 %] # = 8 8
201 · Added string comparison operators (gt ge lt le cmp)
203 [% IF "a" lt "b" %]a is less[% END %]
205 · Added numeric comparison operator (<=>)
207 This can be used to make up for the fact that TT2 made == the same
209 as eq (which will hopefully change - use eq when you mean eq).
210 [% IF ! (a <=> b) %]a == b[% END %]
212 [% IF (a <=> b) %]a != b[% END %]
214 · Added self modifiers (+=, -=, *=, /=, %=, **=, ~=). (TT3)
216 [% a = 2; a *= 3 ; a %] # = 6
218 [% a = 2; (a *= 3) ; a %] # = 66
219 · Added pre and post increment and decrement (++ --). (TT3)
221 [% ++a ; ++a %] # = 12
223 [% a-- ; a-- %] # = 0-1
224 · Added qw// contructor. (TT3)
226 [% a = qw(a b c); a.1 %] # = b
228 [% qw/a b c/.2 %] # = c
230 · Added regex contructor. (TT3)
232 [% "FOO".match(/(foo)/i).0 %] # = FOO
234 [% a = /(foo)/i; "FOO".match(a).0 %] # = FOO
236 · Allow for scientific notation. (TT3)
238 [% a = 1.2e-20 %]
240 [% 123.fmt('%.3e') %] # = 1.230e+02
242 · Allow for hexidecimal input. (TT3)
244 [% a = 0xff0000 %][% a %] # = 16711680
246 [% a = 0xff2 / 0xd; a.fmt('%x') %] # = 13a
248 · FOREACH variables can be nested.
250 [% FOREACH f.b = [1..10] ; f.b ; END %]
252 Note that nested variables are subject to scoping issues. f.b will
254 not be reset to its value before the FOREACH.
255 · Post operative directives can be nested. (TT3)
257 Andy Wardley calls this side-by-side effect notation.
259 [% one IF two IF three %]
261 same as
263 [% IF three %][% IF two %][% one %][% END %][% END %]
265 [% a = [[1..3], [5..7]] %][% i FOREACH i = j FOREACH j = a %] # = 123567
267 · Semi-colons on directives in the same tag are optional. (TT3)
269 [% SET a = 1
271 GET a
272 %]
273 [% FOREACH i = [1 .. 10]
275 i
276 END %]
277 Note: a semi-colon is still required in front of any block direc‐
279 tive that can be used as a post-operative directive.
280 [% 1 IF 0
282 2 %] # prints 2
283 [% 1; IF 0
285 2
286 END %] # prints 1
287 Note2: This behavior can be disabled by setting the SEMICOLONS con‐
289 figuration item to a true value. If SEMICOLONS is true, then a
290 SEMICOLON must be set after any directive that isn't followed by a
291 post-operative directive.
292 · CATCH blocks can be empty.
294 TT2 requires them to contain something.
296 · Added a DUMP directive.
298 Used for Data::Dumpering the passed variable or expression.
300 [% DUMP a.a %]
302 · Added CONFIG directive.
304 [% CONFIG
306 ANYCASE => 1
307 PRE_CHOMP => '-'
308 %]
309 · Configuration options can use lowercase names instead of the all
311 uppercase names that TT2 uses.
312 my $t = Template::Alloy->new({
314 anycase => 1,
315 interpolate => 1,
316 });
317 · Added LOOP directive (works the same as LOOP in HTML::Template.
319 [%- var = [{key => 'a'}, {key => 'b'}] %]
321 [%- LOOP var %]
322 ([% key %])
323 [%- END %]
324 Prints
326 (a)
328 (b)
329 · Alloy can parse HTML::Template and HTML::Template::Expr documents
331 as well as TT2 and TT3 documents.
332 · Added SYNTAX configuration. The SYNTAX configuration can be used
334 to change what template syntax will be used for parsing included
335 templates or eval'ed strings.
336 [% CONFIG SYNTAX => 'hte' %]
338 [% var = '<TMPL_VAR EXPR="sprintf('%s', 'hello world')">' %]
339 [% var ⎪ eval %]
340 · Alloy does not generate Perl code.
342 It generates an "opcode" tree. The opcode tree is an arrayref of
344 scalars and array refs nested as deeply as possible. This "simple"
345 structure could be shared TT implementations in other languages via
346 JSON or YAML.
347 · Alloy uses storable for its compiled templates.
349 If EVAL_PERL is off, Alloy will not eval_string on ANY piece of
351 information.
352 · There is eval_filter and MACRO recursion protection
354 You can control the nested nature of eval_filter and MACRO recur‐
356 sion using the MAX_EVAL_RECURSE and MAX_MACRO_RECURSE configuration
357 items.
358 · There is no context.
360 Alloy provides a context object that mimics the Template::Context
362 interface for use by some TT filters, eval perl blocks, views, and
363 plugins.
364 · There is no provider.
366 Alloy uses the load_template method to get and cache templates.
368 · There is no parser/grammar.
370 Alloy has its own built-in recursive regex based parser and grammar
372 system.
373 Alloy can actually be substituted in place of the native Tem‐
375 plate::Parser and Template::Grammar in TT by using the Tem‐
376 plate::Parser::Alloy module. This module uses the output of
377 parse_tree to generate a TT style compiled perl document.
378 · The DEBUG directive is more limited.
380 It only understands DEBUG_DIRS (8) and DEBUG_UNDEF (2).
382 · Alloy has better line information
384 When debug dirs is on, directives on different lines separated by
386 colons show the line they are on rather than a general line range.
387 Parse errors actually know what line and character they occured at.
389
391 LOAD_TEMPLATES
392 Template::Alloy has its own mechanism for loading and storing com‐
393 piled templates. TT would use a Template::Provider that would
394 return a Template::Document. The closest thing in Template::Alloy
395 is the load_template method. There is no immediate plan to support
396 the TT behavior.
397 LOAD_PLUGINS
399 Template::Alloy uses its own mechanism for loading plugins. TT
400 would use a Template::Plugins object to load plugins requested via
401 the USE directive. The functionality for doing this in Tem‐
402 plate::Alloy is contained in the list_plugins method and the
403 play_USE method. There is no immediate plan to support the TT
404 behavior.
405 Full support is offered for the PLUGINS and LOAD_PERL configuration
407 items.
408 Also note that Template::Alloy only natively supports the Iterator
410 plugin. Any of the other plugins requested will need to provided
411 by installing Template::Toolkit or the appropriate plugin module.
412 LOAD_FILTERS
414 Template::Alloy uses its own mechanism for loading filters. TT
415 would use the Template::Filters object to load filters requested
416 via the FILTER directive. The functionality for doing this in Tem‐
417 plate::Alloy is contained in the list_filters method and the
418 play_expr method.
419 Full support is offered for the FILTERS configuration item.
421 TOLERANT
423 This option is used by the LOAD_TEMPLATES and LOAD_PLUGINS options
424 and is not applicable in Template::Alloy.
425 SERVICE
427 Template::Alloy has no concept of service (theoretically the Tem‐
428 plate::Alloy is the "service").
429 CONTEXT
431 Template::Alloy provides its own pseudo context object to plugins,
432 filters, and perl blocks. The Template::Alloy model doesn't really
433 allow for a separate context. Template::Alloy IS the context.
434 PARSER
436 Template::Alloy has its own built in parser. The closest similar‐
437 ity is the parse_tree method. The output of parse_tree is an
438 optree that is later run by execute_tree. Alloy provides a backend
439 to the Template::Parser::Alloy module which can be used to replace
440 the default parser when using the standard Template::Toolkit
441 library.
442 GRAMMAR
444 Template::Alloy maintains its own grammar. The grammar is defined
445 in the parse_tree method and the callbacks listed in the global
446 $Template::Alloy::Parse::DIRECTIVES hashref.
447
449 Paul Seamons <perl at seamons dot com>
450
452 This module may be distributed under the same terms as Perl itself.
453perl v5.8.8 2007-07-24 Template::Alloy::TT(3)