1Template::Manual::FilteUrsse(r3)Contributed Perl DocumenTteamtpiloante::Manual::Filters(3)
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6 Template::Manual::Filters - Standard filters
7
9 The "format" filter takes a format string as a parameter (as per
10 "printf()") and formats each line of text accordingly.
11 [% FILTER format('<!-- %-40s -->') %]
13 This is a block of text filtered
14 through the above format.
15 [% END %]
16 Output:
18 <!-- This is a block of text filtered -->
20 <!-- through the above format. -->
21
23 Folds the input to UPPER CASE.
24 [% "hello world" FILTER upper %]
26 Output:
28 HELLO WORLD
30
32 Folds the input to lower case.
33 [% "Hello World" FILTER lower %]
35 Output:
37 hello world
39
41 Folds the first character of the input to UPPER CASE.
42 [% "hello" FILTER ucfirst %]
44 Output:
46 Hello
48
50 Folds the first character of the input to lower case.
51 [% "HELLO" FILTER lcfirst %]
53 Output:
55 hELLO
57
59 Trims any leading or trailing whitespace from the input text.
60 Particularly useful in conjunction with "INCLUDE", "PROCESS", etc.,
61 having the same effect as the "TRIM" configuration option.
62 [% INCLUDE myfile | trim %]
64
66 Collapse any whitespace sequences in the input text into a single
67 space. Leading and trailing whitespace (which would be reduced to a
68 single space) is removed, as per trim.
69 [% FILTER collapse %]
71 The cat
73 sat on
75 the mat
77 [% END %]
79 Output:
81 The cat sat on the mat
83
85 Converts the characters "<", ">", "&" and """ to "<", ">",
86 "&", and """ respectively, protecting them from being
87 interpreted as representing HTML tags or entities.
88 [% FILTER html %]
90 Binary "<=>" returns -1, 0, or 1 depending on...
91 [% END %]
92 Output:
94 Binary "<=>" returns -1, 0, or 1 depending on...
96
98 The "html" filter is fast and simple but it doesn't encode the full
99 range of HTML entities that your text may contain. The "html_entity"
100 filter uses either the "Apache::Util" module (which is written in C and
101 is therefore faster) or the "HTML::Entities" module (written in Perl
102 but equally as comprehensive) to perform the encoding.
103 If one or other of these modules are installed on your system then the
105 text will be encoded (via the "escape_html()" or "encode_entities()"
106 subroutines respectively) to convert all extended characters into their
107 appropriate HTML entities (e.g. converting '"e"' to '"é"'). If
108 neither module is available on your system then an '"html_entity"'
109 exception will be thrown reporting an appropriate message.
110 If you want to force TT to use one of the above modules in preference
112 to the other, then call either of the Template::Filters class methods:
113 use_html_entities() or use_apache_util().
114 use Template::Filters;
116 Template::Filters->use_html_entities;
117 For further information on HTML entity encoding, see
119 http://www.w3.org/TR/REC-html40/sgml/entities.html
120 <http://www.w3.org/TR/REC-html40/sgml/entities.html>.
121
123 Same as the "html" filter, but adds "'" which is the fifth XML
124 built-in entity.
125
127 This filter formats a block of text into HTML paragraphs. A sequence
128 of two or more newlines is used as the delimiter for paragraphs which
129 are then wrapped in HTML "<p>"..."</p>" tags.
130 [% FILTER html_para %]
132 The cat sat on the mat.
133 Mary had a little lamb.
135 [% END %]
136 Output:
138 <p>
140 The cat sat on the mat.
141 </p>
142 <p>
144 Mary had a little lamb.
145 </p>
146
148 Similar to the html_para filter described above, but uses the HTML tag
149 sequence "<br><br>" to join paragraphs.
150 [% FILTER html_break %]
152 The cat sat on the mat.
153 Mary had a little lamb.
155 [% END %]
156 Output:
158 The cat sat on the mat.
160 <br>
161 <br>
162 Mary had a little lamb.
163
165 This filter replaces any newlines with "<br>" HTML tags, thus
166 preserving the line breaks of the original text in the HTML output.
167 [% FILTER html_line_break %]
169 The cat sat on the mat.
170 Mary had a little lamb.
171 [% END %]
172 Output:
174 The cat sat on the mat.<br>
176 Mary had a little lamb.<br>
177
179 This filter URI escapes the input text, converting any characters
180 outside of the permitted URI character set (as defined by RFC 2396)
181 into a %nn hex escape.
182 [% 'my file.html' | uri %]
184 Output:
186 my%20file.html
188 The uri filter correctly encodes all reserved characters, including
190 "&", "@", "/", ";", ":", "=", "+", "?" and "$". This filter is
191 typically used to encode parameters in a URL that could otherwise be
192 interpreted as part of the URL. Here's an example:
193 [% path = 'http://tt2.org/example'
195 back = '/other?foo=bar&baz=bam'
196 title = 'Earth: "Mostly Harmless"'
197 %]
198 <a href="[% path %]?back=[% back | uri %]&title=[% title | uri %]">
199 The output generated is rather long so we'll show it split across two
201 lines:
202 <a href="http://tt2.org/example?back=%2Fother%3Ffoo%3Dbar%26
204 baz%3Dbam&title=Earth%3A%20%22Mostly%20Harmless%22">
205 Without the uri filter the output would look like this (also split
207 across two lines).
208 <a href="http://tt2.org/example?back=/other?foo=bar
210 &baz=bam&title=Earth: "Mostly Harmless"">
211 In this rather contrived example we've manage to generate both a broken
213 URL (the repeated "?" is not allowed) and a broken HTML element (the
214 href attribute is terminated by the first """ after "Earth: " leaving
215 "Mostly Harmless"" dangling on the end of the tag in precisely the way
216 that harmless things shouldn't dangle). So don't do that. Always use
217 the uri filter to encode your URL parameters.
218 However, you should not use the uri filter to encode an entire URL.
220 <a href="[% page_url | uri %]"> # WRONG!
222 This will incorrectly encode any reserved characters like ":" and "/"
224 and that's almost certainly not what you want in this case. Instead
225 you should use the url (note spelling) filter for this purpose.
226 <a href="[% page_url | url %]"> # CORRECT
228 Please note that this behaviour was changed in version 2.16 of the
230 Template Toolkit. Prior to that, the uri filter did not encode the
231 reserved characters, making it technically incorrect according to the
232 RFC 2396 specification. So we fixed it in 2.16 and provided the url
233 filter to implement the old behaviour of not encoding reserved
234 characters.
235
237 The url filter is a less aggressive version of the uri filter. It
238 encodes any characters outside of the permitted URI character set (as
239 defined by RFC 2396) into %nn hex escapes. However, unlike the uri
240 filter, the url filter does not encode the reserved characters "&",
241 "@", "/", ";", ":", "=", "+", "?" and "$".
242
244 Indents the text block by a fixed pad string or width. The '"pad"'
245 argument can be specified as a string, or as a numerical value to
246 indicate a pad width (spaces). Defaults to 4 spaces if unspecified.
247 [% FILTER indent('ME> ') %]
249 blah blah blah
250 cabbages, rhubard, onions
251 [% END %]
252 Output:
254 ME> blah blah blah
256 ME> cabbages, rhubard, onions
257
259 Truncates the text block to the length specified, or a default length
260 of 32. Truncated text will be terminated with '"..."' (i.e. the
261 '"..."' falls inside the required length, rather than appending to
262 it).
263 [% FILTER truncate(21) %]
265 I have much to say on this matter that has previously
266 been said on more than one occasion.
267 [% END %]
268 Output:
270 I have much to say...
272 If you want to use something other than '"..."' you can pass that as a
274 second argument.
275 [% FILTER truncate(26, '…') %]
277 I have much to say on this matter that has previously
278 been said on more than one occasion.
279 [% END %]
280 Output:
282 I have much to say…
284
286 Repeats the text block for as many iterations as are specified
287 (default: 1).
288 [% FILTER repeat(3) %]
290 We want more beer and we want more beer,
291 [% END %]
292 We are the more beer wanters!
293 Output:
295 We want more beer and we want more beer,
297 We want more beer and we want more beer,
298 We want more beer and we want more beer,
299 We are the more beer wanters!
300
302 Searches the input text for any occurrences of the specified string and
303 removes them. A Perl regular expression may be specified as the search
304 string.
305 [% "The cat sat on the mat" FILTER remove('\s+') %]
307 Output:
309 Thecatsatonthemat
311
313 Similar to the remove filter described above, but taking a second
314 parameter which is used as a replacement string for instances of the
315 search string.
316 [% "The cat sat on the mat" | replace('\s+', '_') %]
318 Output:
320 The_cat_sat_on_the_mat
322
324 The "redirect" filter redirects the output of the block into a separate
325 file, specified relative to the "OUTPUT_PATH" configuration item.
326 [% FOREACH user IN myorg.userlist %]
328 [% FILTER redirect("users/${user.id}.html") %]
329 [% INCLUDE userinfo %]
330 [% END %]
331 [% END %]
332 or more succinctly, using side-effect notation:
334 [% FOREACH user IN myorg.userlist;
336 INCLUDE userinfo
337 FILTER redirect("users/${user.id}.html");
338 END
339 %]
340 A "file" exception will be thrown if the "OUTPUT_PATH" option is
342 undefined.
343 An optional "binmode" argument can follow the filename to explicitly
345 set the output file to binary mode.
346 [% PROCESS my/png/generator
348 FILTER redirect("images/logo.png", binmode=1) %]
349 For backwards compatibility with earlier versions, a single true/false
351 value can be used to set binary mode.
352 [% PROCESS my/png/generator
354 FILTER redirect("images/logo.png", 1) %]
355 For the sake of future compatibility and clarity, if nothing else, we
357 would strongly recommend you explicitly use the named "binmode" option
358 as shown in the first example.
359
361 The "eval" filter evaluates the block as template text, processing any
362 directives embedded within it. This allows template variables to
363 contain template fragments, or for some method to be provided for
364 returning template fragments from an external source such as a
365 database, which can then be processed in the template as required.
366 my $vars = {
368 fragment => "The cat sat on the [% place %]",
369 };
370 $template->process($file, $vars);
371 The following example:
373 [% fragment | eval %]
375 is therefore equivalent to
377 The cat sat on the [% place %]
379 The "evaltt" filter is provided as an alias for "eval".
381
383 The "perl" filter evaluates the block as Perl code. The "EVAL_PERL"
384 option must be set to a true value or a "perl" exception will be
385 thrown.
386 [% my_perl_code | perl %]
388 In most cases, the "[% PERL %]" ... "[% END %]" block should suffice
390 for evaluating Perl code, given that template directives are processed
391 before being evaluate as Perl. Thus, the previous example could have
392 been written in the more verbose form:
393 [% PERL %]
395 [% my_perl_code %]
396 [% END %]
397 as well as
399 [% FILTER perl %]
401 [% my_perl_code %]
402 [% END %]
403 The "evalperl" filter is provided as an alias for "perl" for backwards
405 compatibility.
406
408 The stdout filter prints the output generated by the enclosing block to
409 "STDOUT". The "binmode" option can be passed as either a named
410 parameter or a single argument to set "STDOUT" to binary mode (see the
411 binmode perl function).
412 [% PROCESS something/cool
414 FILTER stdout(binmode=1) # recommended %]
415 [% PROCESS something/cool
417 FILTER stdout(1) # alternate %]
418 The "stdout" filter can be used to force "binmode" on "STDOUT", or also
420 inside "redirect", "null" or "stderr" blocks to make sure that
421 particular output goes to "STDOUT". See the "null" filter below for an
422 example.
423
425 The stderr filter prints the output generated by the enclosing block to
426 "STDERR".
427
429 The "null" filter prints nothing. This is useful for plugins whose
430 methods return values that you don't want to appear in the output.
431 Rather than assigning every plugin method call to a dummy variable to
432 silence it, you can wrap the block in a null filter:
433 [% FILTER null;
435 USE im = GD.Image(100,100);
436 black = im.colorAllocate(0, 0, 0);
437 red = im.colorAllocate(255,0, 0);
438 blue = im.colorAllocate(0, 0, 255);
439 im.arc(50,50,95,75,0,360,blue);
440 im.fill(50,50,red);
441 im.png | stdout(1);
442 END;
443 -%]
444 Notice the use of the "stdout" filter to ensure that a particular
446 expression generates output to "STDOUT" (in this case in binary mode).
447perl v5.12.0 2009-04-07 Template::Manual::Filters(3)