1HTML::Tiny(3) User Contributed Perl Documentation HTML::Tiny(3)
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3
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6 HTML::Tiny - Lightweight, dependency free HTML/XML generation
7
9 This document describes HTML::Tiny version 1.05
10
12 use HTML::Tiny;
13
14 my $h = HTML::Tiny->new;
15
16 # Generate a simple page
17 print $h->html(
18 [
19 $h->head( $h->title( 'Sample page' ) ),
20 $h->body(
21 [
22 $h->h1( { class => 'main' }, 'Sample page' ),
23 $h->p( 'Hello, World', { class => 'detail' }, 'Second para' )
24 ]
25 )
26 ]
27 );
28
29 # Outputs
30 <html>
31 <head>
32 <title>Sample page</title>
33 </head>
34 <body>
35 <h1 class="main">Sample page</h1>
36 <p>Hello, World</p>
37 <p class="detail">Second para</p>
38 </body>
39 </html>
40
42 "HTML::Tiny" is a simple, dependency free module for generating HTML
43 (and XML). It concentrates on generating syntactically correct XHTML
44 using a simple Perl notation.
45
46 In addition to the HTML generation functions utility functions are
47 provided to
48
49 · encode and decode URL encoded strings
50
51 · entity encode HTML
52
53 · build query strings
54
55 · JSON encode data structures
56
58 "new"
59 Create a new "HTML::Tiny". The constructor takes one optional
60 argument: "mode". "mode" can be either 'xml' (default) or 'html'.
61 The difference is that in HTML mode, closed tags will not be closed
62 with a forward slash; instead, closed tags will be returned as
63 single open tags.
64
65 Example:
66
67 # Set HTML mode.
68 my $h = HTML::Tiny->new( mode => 'html' );
69
70 # The default is XML mode, but this can also be defined explicitly.
71 $h = HTML::Tiny->new( mode => 'xml' );
72
73 HTML is a dialect of SGML, and is not XML in any way. "Orphan" open
74 tags or unclosed tags are legal and in fact expected by user
75 agents. In practice, if you want to generate XML or XHTML, supply
76 no arguments. If you want valid HTML, use "mode => 'html'".
77
78 HTML Generation
79 "tag( $name, ... )"
80 Returns HTML (or XML) that encloses each of the arguments in the
81 specified tag. For example
82
83 print $h->tag('p', 'Hello', 'World');
84
85 would print
86
87 <p>Hello</p><p>World</p>
88
89 notice that each argument is individually wrapped in the specified
90 tag. To avoid this multiple arguments can be grouped in an
91 anonymous array:
92
93 print $h->tag('p', ['Hello', 'World']);
94
95 would print
96
97 <p>HelloWorld</p>
98
99 The [ and ] can be thought of as grouping a number of arguments.
100
101 Attributes may be supplied by including an anonymous hash in the
102 argument list:
103
104 print $h->tag('p', { class => 'normal' }, 'Foo');
105
106 would print
107
108 <p class="normal">Foo</p>
109
110 Attribute values will be HTML entity encoded as necessary.
111
112 Multiple hashes may be supplied in which case they will be merged:
113
114 print $h->tag('p',
115 { class => 'normal' }, 'Bar',
116 { style => 'color: red' }, 'Bang!'
117 );
118
119 would print
120
121 <p class="normal">Bar</p><p class="normal" style="color: red">Bang!</p>
122
123 Notice that the class="normal" attribute is merged with the style
124 attribute for the second paragraph.
125
126 To remove an attribute set its value to undef:
127
128 print $h->tag('p',
129 { class => 'normal' }, 'Bar',
130 { class => undef }, 'Bang!'
131 );
132
133 would print
134
135 <p class="normal">Bar</p><p>Bang!</p>
136
137 An empty attribute - such as 'checked' in a checkbox can be encoded
138 by passing an empty array reference:
139
140 print $h->closed( 'input', { type => 'checkbox', checked => [] } );
141
142 would print
143
144 <input checked type="checkbox" />
145
146 Return Value
147
148 In a scalar context "tag" returns a string. In a list context it
149 returns an array each element of which corresponds to one of the
150 original arguments:
151
152 my @html = $h->tag('p', 'this', 'that');
153
154 would return
155
156 @html = (
157 '<p>this</p>',
158 '<p>that</p>'
159 );
160
161 That means that when you nest calls to tag (or the equivalent HTML
162 aliases - see below) the individual arguments to the inner call
163 will be tagged separately by each enclosing call. In practice this
164 means that
165
166 print $h->tag('p', $h->tag('b', 'Foo', 'Bar'));
167
168 would print
169
170 <p><b>Foo</b></p><p><b>Bar</b></p>
171
172 You can modify this behavior by grouping multiple args in an
173 anonymous array:
174
175 print $h->tag('p', [ $h->tag('b', 'Foo', 'Bar') ] );
176
177 would print
178
179 <p><b>Foo</b><b>Bar</b></p>
180
181 This behaviour is powerful but can take a little time to master. If
182 you imagine '[' and ']' preventing the propagation of the 'tag
183 individual items' behaviour it might help visualise how it works.
184
185 Here's an HTML table (using the tag-name convenience methods - see
186 below) that demonstrates it in more detail:
187
188 print $h->table(
189 [
190 $h->tr(
191 [ $h->th( 'Name', 'Score', 'Position' ) ],
192 [ $h->td( 'Therese', 90, 1 ) ],
193 [ $h->td( 'Chrissie', 85, 2 ) ],
194 [ $h->td( 'Andy', 50, 3 ) ]
195 )
196 ]
197 );
198
199 which would print the unformatted version of:
200
201 <table>
202 <tr><th>Name</th><th>Score</th><th>Position</th></tr>
203 <tr><td>Therese</td><td>90</td><td>1</td></tr>
204 <tr><td>Chrissie</td><td>85</td><td>2</td></tr>
205 <tr><td>Andy</td><td>50</td><td>3</td></tr>
206 </table>
207
208 Note how you don't need a td() for every cell or a tr() for every
209 row. Notice also how the square brackets around the rows prevent
210 tr() from wrapping each individual cell.
211
212 Often when generating nested HTML you will find yourself writing
213 corresponding nested calls to HTML generation methods. The table
214 generation code above is an example of this.
215
216 If you prefer these nested method calls can be deferred like this:
217
218 print $h->table(
219 [
220 \'tr',
221 [ \'th', 'Name', 'Score', 'Position' ],
222 [ \'td', 'Therese', 90, 1 ],
223 [ \'td', 'Chrissie', 85, 2 ],
224 [ \'td', 'Andy', 50, 3 ]
225 ]
226 );
227
228 In general a nested call like
229
230 $h->method( args )
231
232 may be rewritten like this
233
234 [ \'method', args ]
235
236 This allows complex HTML to be expressed as a pure data structure.
237 See the "stringify" method for more information.
238
239 "open( $name, ... )"
240 Generate an opening HTML or XML tag. For example:
241
242 print $h->open('marker');
243
244 would print
245
246 <marker>
247
248 Attributes can be provided in the form of anonymous hashes in the
249 same way as for "tag". For example:
250
251 print $h->open('marker', { lat => 57.0, lon => -2 });
252
253 would print
254
255 <marker lat="57.0" lon="-2">
256
257 As for "tag" multiple attribute hash references will be merged. The
258 example above could be written:
259
260 print $h->open('marker', { lat => 57.0 }, { lon => -2 });
261
262 "close( $name )"
263 Generate a closing HTML or XML tag. For example:
264
265 print $h->close('marker');
266
267 would print:
268
269 </marker>
270
271 "closed( $name, ... )"
272 Generate a closed HTML or XML tag. For example
273
274 print $h->closed('marker');
275
276 would print:
277
278 <marker />
279
280 As for "tag" and "open" attributes may be provided as hash
281 references:
282
283 print $h->closed('marker', { lat => 57.0 }, { lon => -2 });
284
285 would print:
286
287 <marker lat="57.0" lon="-2" />
288
289 "auto_tag( $name, ... )"
290 Calls either "tag" or "closed" based on built in rules for the tag.
291 Used internally to implement the tag-named methods.
292
293 "stringify( $obj )"
294 Called internally to obtain string representations of values.
295
296 It also implements the deferred method call notation (mentioned
297 above) so that
298
299 my $table = $h->table(
300 [
301 $h->tr(
302 [ $h->th( 'Name', 'Score', 'Position' ) ],
303 [ $h->td( 'Therese', 90, 1 ) ],
304 [ $h->td( 'Chrissie', 85, 2 ) ],
305 [ $h->td( 'Andy', 50, 3 ) ]
306 )
307 ]
308 );
309
310 may also be written like this:
311
312 my $table = $h->stringify(
313 [
314 \'table',
315 [
316 \'tr',
317 [ \'th', 'Name', 'Score', 'Position' ],
318 [ \'td', 'Therese', 90, 1 ],
319 [ \'td', 'Chrissie', 85, 2 ],
320 [ \'td', 'Andy', 50, 3 ]
321 ]
322 ]
323 );
324
325 Any reference to an array whose first element is a reference to a
326 scalar
327
328 [ \'methodname', args ]
329
330 is executed as a call to the named method with the specified args.
331
332 Methods named after tags
333 In addition to the methods described above "HTML::Tiny" provides all of
334 the following HTML generation methods:
335
336 a abbr acronym address area b base bdo big blockquote body br
337 button caption cite code col colgroup dd del div dfn dl dt em
338 fieldset form frame frameset h1 h2 h3 h4 h5 h6 head hr html i
339 iframe img input ins kbd label legend li link map meta noframes
340 noscript object ol optgroup option p param pre q samp script select
341 small span strong style sub sup table tbody td textarea tfoot th
342 thead title tr tt ul var
343
344 The following methods generate closed XHTML (<br />) tags by default:
345
346 area base br col frame hr img input meta param
347
348 So:
349
350 print $h->br; # prints <br />
351 print $h->input({ name => 'field1' });
352 # prints <input name="field1" />
353 print $h->img({ src => 'pic.jpg' });
354 # prints <img src="pic.jpg" />
355
356 All other tag methods generate tags to wrap whatever content they are
357 passed:
358
359 print $h->p('Hello, World');
360
361 prints:
362
363 <p>Hello, World</p>
364
365 So the following are equivalent:
366
367 print $h->a({ href => 'http://hexten.net' }, 'Hexten');
368
369 and
370
371 print $h->tag('a', { href => 'http://hexten.net' }, 'Hexten');
372
373 Utility Methods
374 "url_encode( $str )"
375 URL encode a string. Spaces become '+' and non-alphanumeric
376 characters are encoded as '%' + their hexadecimal character code.
377
378 $h->url_encode( ' <hello> ' ) # returns '+%3chello%3e+'
379
380 "url_decode( $str )"
381 URL decode a string. Reverses the effect of "url_encode".
382
383 $h->url_decode( '+%3chello%3e+' ) # returns ' <hello> '
384
385 "query_encode( $hash_ref )"
386 Generate a query string from an anonymous hash of key, value pairs:
387
388 print $h->query_encode({ a => 1, b => 2 })
389
390 would print
391
392 a=1&b=2
393
394 "entity_encode( $str )"
395 Encode the characters '<', '>', '&', '\'' and '"' as their HTML
396 entity equivalents:
397
398 print $h->entity_encode( '<>\'"&' );
399
400 would print:
401
402 <>'"&
403
404 "json_encode"
405 Encode a data structure in JSON (Javascript) format:
406
407 print $h->json_encode( { ar => [ 1, 2, 3, { a => 1, b => 2 } ] } );
408
409 would print:
410
411 {"ar":[1,2,3,{"a":1,"b":2}]}
412
413 Because JSON is valid Javascript this method can be useful when
414 generating ad-hoc Javascript. For example
415
416 my $some_perl_data = {
417 score => 45,
418 name => 'Fred',
419 history => [ 32, 37, 41, 45 ]
420 };
421
422 # Transfer value to Javascript
423 print $h->script( { type => 'text/javascript' },
424 "\nvar someVar = " . $h->json_encode( $some_perl_data ) . ";\n " );
425
426 # Prints
427 # <script type="text/javascript">
428 # var someVar = {"history":[32,37,41,45],"name":"Fred","score":45};
429 # </script>
430
431 If you attempt to json encode a blessed object "json_encode" will
432 look for a "TO_JSON" method and, if found, use its return value as
433 the structure to be converted in place of the object. An attempt to
434 encode a blessed object that does not implement "TO_JSON" will
435 fail.
436
437 Subclassing
438 An "HTML::Tiny" is a blessed hash ref.
439
440 "validate_tag( $closed, $name, $attr )"
441 Subclass "validate_tag" to throw an error or issue a warning when
442 an attempt is made to generate an invalid tag.
443
445 HTML::Tiny requires no configuration files or environment variables.
446
448 By design HTML::Tiny has no non-core dependencies.
449
450 To run the tests you will require Test::More.
451
453 None reported.
454
456 No bugs have been reported.
457
458 Please report any bugs or feature requests to
459 "bug-html-tiny@rt.cpan.org", or through the web interface at
460 <http://rt.cpan.org>.
461
463 Andy Armstrong "<andy@hexten.net>"
464
465 Aristotle Pagaltzis "<pagaltzis@gmx.de>"
466
468 Copyright (c) 2008, Andy Armstrong "<andy@hexten.net>". All rights
469 reserved.
470
471 This module is free software; you can redistribute it and/or modify it
472 under the same terms as Perl itself. See perlartistic.
473
475 BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
476 FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT
477 WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER
478 PARTIES PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND,
479 EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
480 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
481 ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH
482 YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL
483 NECESSARY SERVICING, REPAIR, OR CORRECTION.
484
485 IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
486 WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
487 REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENCE, BE LIABLE
488 TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL, OR
489 CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE
490 SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING
491 RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A
492 FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF
493 SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
494 DAMAGES.
495
496
497
498perl v5.12.0 2009-03-08 HTML::Tiny(3)