Commit | Line | Data |
d80786d0 |
1 | package HTML::Zoom; |
2 | |
1cf03540 |
3 | use strictures 1; |
d80786d0 |
4 | |
5 | use HTML::Zoom::ZConfig; |
bf5a23d0 |
6 | use HTML::Zoom::ReadFH; |
655965b3 |
7 | use HTML::Zoom::Transform; |
eeeb0921 |
8 | use HTML::Zoom::TransformBuilder; |
94a3ddd9 |
9 | use Scalar::Util (); |
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10 | |
a5d7c5f6 |
11 | our $VERSION = '0.009006'; |
7af7362d |
12 | |
13 | $VERSION = eval $VERSION; |
14 | |
d80786d0 |
15 | sub new { |
16 | my ($class, $args) = @_; |
17 | my $new = {}; |
18 | $new->{zconfig} = HTML::Zoom::ZConfig->new($args->{zconfig}||{}); |
19 | bless($new, $class); |
20 | } |
21 | |
22 | sub zconfig { shift->_self_or_new->{zconfig} } |
23 | |
24 | sub _self_or_new { |
25 | ref($_[0]) ? $_[0] : $_[0]->new |
26 | } |
27 | |
28 | sub _with { |
29 | bless({ %{$_[0]}, %{$_[1]} }, ref($_[0])); |
30 | } |
31 | |
7567494d |
32 | sub from_events { |
d80786d0 |
33 | my $self = shift->_self_or_new; |
34 | $self->_with({ |
7567494d |
35 | initial_events => shift, |
d80786d0 |
36 | }); |
37 | } |
38 | |
7567494d |
39 | sub from_html { |
40 | my $self = shift->_self_or_new; |
41 | $self->from_events($self->zconfig->parser->html_to_events($_[0])) |
42 | } |
43 | |
bf5a23d0 |
44 | sub from_file { |
45 | my $self = shift->_self_or_new; |
46 | my $filename = shift; |
47 | $self->from_html(do { local (@ARGV, $/) = ($filename); <> }); |
48 | } |
49 | |
d80786d0 |
50 | sub to_stream { |
51 | my $self = shift; |
52 | die "No events to build from - forgot to call from_html?" |
53 | unless $self->{initial_events}; |
54 | my $sutils = $self->zconfig->stream_utils; |
55 | my $stream = $sutils->stream_from_array(@{$self->{initial_events}}); |
2f0c6a86 |
56 | $stream = $_->apply_to_stream($stream) for @{$self->{transforms}||[]}; |
d80786d0 |
57 | $stream |
58 | } |
59 | |
bf5a23d0 |
60 | sub to_fh { |
61 | HTML::Zoom::ReadFH->from_zoom(shift); |
62 | } |
63 | |
7567494d |
64 | sub to_events { |
65 | my $self = shift; |
66 | [ $self->zconfig->stream_utils->stream_to_array($self->to_stream) ]; |
67 | } |
68 | |
bf5a23d0 |
69 | sub run { |
70 | my $self = shift; |
7567494d |
71 | $self->to_events; |
bf5a23d0 |
72 | return |
73 | } |
74 | |
75 | sub apply { |
76 | my ($self, $code) = @_; |
77 | local $_ = $self; |
78 | $self->$code; |
79 | } |
80 | |
fdb039c6 |
81 | sub apply_if { |
82 | my ($self, $predicate, $code) = @_; |
83 | if($predicate) { |
84 | local $_ = $self; |
85 | $self->$code; |
86 | } |
87 | else { |
88 | $self; |
89 | } |
90 | } |
91 | |
d80786d0 |
92 | sub to_html { |
93 | my $self = shift; |
94 | $self->zconfig->producer->html_from_stream($self->to_stream); |
95 | } |
96 | |
97 | sub memoize { |
98 | my $self = shift; |
99 | ref($self)->new($self)->from_html($self->to_html); |
100 | } |
101 | |
eeeb0921 |
102 | sub with_transform { |
1c4455ae |
103 | my $self = shift->_self_or_new; |
eeeb0921 |
104 | my ($transform) = @_; |
d80786d0 |
105 | $self->_with({ |
2f0c6a86 |
106 | transforms => [ |
107 | @{$self->{transforms}||[]}, |
eeeb0921 |
108 | $transform |
2f0c6a86 |
109 | ] |
d80786d0 |
110 | }); |
111 | } |
eeeb0921 |
112 | |
113 | sub with_filter { |
114 | my $self = shift->_self_or_new; |
115 | my ($selector, $filter) = @_; |
116 | $self->with_transform( |
117 | HTML::Zoom::Transform->new({ |
118 | zconfig => $self->zconfig, |
119 | selector => $selector, |
120 | filters => [ $filter ] |
121 | }) |
122 | ); |
123 | } |
d80786d0 |
124 | |
125 | sub select { |
1c4455ae |
126 | my $self = shift->_self_or_new; |
127 | my ($selector) = @_; |
eeeb0921 |
128 | return HTML::Zoom::TransformBuilder->new({ |
129 | zconfig => $self->zconfig, |
130 | selector => $selector, |
131 | proto => $self |
132 | }); |
d80786d0 |
133 | } |
134 | |
135 | # There's a bug waiting to happen here: if you do something like |
136 | # |
137 | # $zoom->select('.foo') |
1c4455ae |
138 | # ->remove_attribute(class => 'foo') |
d80786d0 |
139 | # ->then |
140 | # ->well_anything_really |
141 | # |
142 | # the second action won't execute because it doesn't match anymore. |
143 | # Ideally instead we'd merge the match subs but that's more complex to |
144 | # implement so I'm deferring it for the moment. |
145 | |
146 | sub then { |
147 | my $self = shift; |
2f0c6a86 |
148 | die "Can't call ->then without a previous transform" |
149 | unless $self->{transforms}; |
150 | $self->select($self->{transforms}->[-1]->selector); |
d80786d0 |
151 | } |
152 | |
94a3ddd9 |
153 | sub AUTOLOAD { |
154 | my ($self, $selector, @args) = @_; |
155 | my $sel = $self->select($selector); |
156 | my $meth = our $AUTOLOAD; |
157 | $meth =~ s/.*:://; |
158 | if(my $cr = $sel->_zconfig->filter_builder->can($meth)) { |
159 | return $sel->$meth(@args); |
160 | } else { |
161 | die "We can't do $meth on ->select('$selector')"; |
162 | } |
163 | } |
164 | |
268f2c35 |
165 | sub DESTROY {} |
166 | |
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167 | 1; |
168 | |
169 | =head1 NAME |
170 | |
171 | HTML::Zoom - selector based streaming template engine |
172 | |
173 | =head1 SYNOPSIS |
174 | |
175 | use HTML::Zoom; |
176 | |
177 | my $template = <<HTML; |
178 | <html> |
179 | <head> |
180 | <title>Hello people</title> |
181 | </head> |
182 | <body> |
183 | <h1 id="greeting">Placeholder</h1> |
184 | <div id="list"> |
185 | <span> |
186 | <p>Name: <span class="name">Bob</span></p> |
187 | <p>Age: <span class="age">23</span></p> |
188 | </span> |
189 | <hr class="between" /> |
190 | </div> |
191 | </body> |
192 | </html> |
193 | HTML |
194 | |
195 | my $output = HTML::Zoom |
196 | ->from_html($template) |
197 | ->select('title, #greeting')->replace_content('Hello world & dog!') |
198 | ->select('#list')->repeat_content( |
199 | [ |
200 | sub { |
201 | $_->select('.name')->replace_content('Matt') |
202 | ->select('.age')->replace_content('26') |
203 | }, |
204 | sub { |
205 | $_->select('.name')->replace_content('Mark') |
206 | ->select('.age')->replace_content('0x29') |
207 | }, |
208 | sub { |
209 | $_->select('.name')->replace_content('Epitaph') |
210 | ->select('.age')->replace_content('<redacted>') |
211 | }, |
212 | ], |
213 | { repeat_between => '.between' } |
214 | ) |
215 | ->to_html; |
216 | |
217 | will produce: |
218 | |
219 | =begin testinfo |
220 | |
221 | my $expect = <<HTML; |
222 | |
223 | =end testinfo |
224 | |
225 | <html> |
226 | <head> |
227 | <title>Hello world & dog!</title> |
228 | </head> |
229 | <body> |
230 | <h1 id="greeting">Hello world & dog!</h1> |
231 | <div id="list"> |
232 | <span> |
233 | <p>Name: <span class="name">Matt</span></p> |
234 | <p>Age: <span class="age">26</span></p> |
235 | </span> |
236 | <hr class="between" /> |
237 | <span> |
238 | <p>Name: <span class="name">Mark</span></p> |
239 | <p>Age: <span class="age">0x29</span></p> |
240 | </span> |
241 | <hr class="between" /> |
242 | <span> |
243 | <p>Name: <span class="name">Epitaph</span></p> |
244 | <p>Age: <span class="age"><redacted></span></p> |
245 | </span> |
246 | |
247 | </div> |
248 | </body> |
249 | </html> |
250 | |
251 | =begin testinfo |
252 | |
253 | HTML |
254 | is($output, $expect, 'Synopsis code works ok'); |
255 | |
256 | =end testinfo |
257 | |
1c4455ae |
258 | =head1 DANGER WILL ROBINSON |
259 | |
260 | This is a 0.9 release. That means that I'm fairly happy the API isn't going |
261 | to change in surprising and upsetting ways before 1.0 and a real compatibility |
262 | freeze. But it also means that if it turns out there's a mistake the size of |
263 | a politician's ego in the API design that I haven't spotted yet there may be |
264 | a bit of breakage between here and 1.0. Hopefully not though. Appendages |
265 | crossed and all that. |
266 | |
267 | Worse still, the rest of the distribution isn't documented yet. I'm sorry. |
268 | I suck. But lots of people have been asking me to ship this, docs or no, so |
269 | having got this class itself at least somewhat documented I figured now was |
270 | a good time to cut a first real release. |
271 | |
272 | =head1 DESCRIPTION |
273 | |
274 | HTML::Zoom is a lazy, stream oriented, streaming capable, mostly functional, |
275 | CSS selector based semantic templating engine for HTML and HTML-like |
276 | document formats. |
277 | |
278 | Which is, on the whole, a bit of a mouthful. So let me step back a moment |
279 | and explain why you care enough to understand what I mean: |
280 | |
281 | =head2 JQUERY ENVY |
282 | |
283 | HTML::Zoom is the cure for JQuery envy. When your javascript guy pushes a |
284 | piece of data into a document by doing: |
285 | |
286 | $('.username').replaceAll(username); |
287 | |
288 | In HTML::Zoom one can write |
289 | |
290 | $zoom->select('.username')->replace_content($username); |
291 | |
292 | which is, I hope, almost as clear, hampered only by the fact that Zoom can't |
293 | assume a global document and therefore has nothing quite so simple as the |
294 | $() function to get the initial selection. |
295 | |
296 | L<HTML::Zoom::SelectorParser> implements a subset of the JQuery selector |
297 | specification, and will continue to track that rather than the W3C standards |
298 | for the forseeable future on grounds of pragmatism. Also on grounds of their |
299 | spec is written in EN_US rather than EN_W3C, and I read the former much better. |
300 | |
301 | I am happy to admit that it's very, very much a subset at the moment - see the |
302 | L<HTML::Zoom::SelectorParser> POD for what's currently there, and expect more |
303 | and more to be supported over time as we need it and patch it in. |
304 | |
305 | =head2 CLEAN TEMPLATES |
306 | |
307 | HTML::Zoom is the cure for messy templates. How many times have you looked at |
308 | templates like this: |
309 | |
310 | <form action="/somewhere"> |
311 | [% FOREACH field IN fields %] |
312 | <label for="[% field.id %]">[% field.label %]</label> |
313 | <input name="[% field.name %]" type="[% field.type %]" value="[% field.value %]" /> |
314 | [% END %] |
315 | </form> |
316 | |
317 | and despaired of the fact that neither the HTML structure nor the logic are |
318 | remotely easy to read? Fortunately, with HTML::Zoom we can separate the two |
319 | cleanly: |
320 | |
321 | <form class="myform" action="/somewhere"> |
322 | <label /> |
323 | <input /> |
324 | </form> |
325 | |
326 | $zoom->select('.myform')->repeat_content([ |
327 | map { my $field = $_; sub { |
328 | |
329 | $_->select('label') |
2daa653a |
330 | ->add_to_attribute( for => $field->{id} ) |
1c4455ae |
331 | ->then |
332 | ->replace_content( $field->{label} ) |
333 | |
334 | ->select('input') |
2daa653a |
335 | ->add_to_attribute( name => $field->{name} ) |
1c4455ae |
336 | ->then |
2daa653a |
337 | ->add_to_attribute( type => $field->{type} ) |
1c4455ae |
338 | ->then |
2daa653a |
339 | ->add_to_attribute( value => $field->{value} ) |
1c4455ae |
340 | |
341 | } } @fields |
342 | ]); |
343 | |
344 | This is, admittedly, very much not shorter. However, it makes it extremely |
345 | clear what's happening and therefore less hassle to maintain. Especially |
346 | because it allows the designer to fiddle with the HTML without cutting |
347 | himself on sharp ELSE clauses, and the developer to add available data to |
348 | the template without getting angle bracket cuts on sensitive parts. |
349 | |
350 | Better still, HTML::Zoom knows that it's inserting content into HTML and |
351 | can escape it for you - the example template should really have been: |
352 | |
353 | <form action="/somewhere"> |
354 | [% FOREACH field IN fields %] |
355 | <label for="[% field.id | html %]">[% field.label | html %]</label> |
356 | <input name="[% field.name | html %]" type="[% field.type | html %]" value="[% field.value | html %]" /> |
357 | [% END %] |
358 | </form> |
359 | |
360 | and frankly I'll take slightly more code any day over *that* crawling horror. |
361 | |
362 | (addendum: I pick on L<Template Toolkit|Template> here specifically because |
363 | it's the template system I hate the least - for text templating, I don't |
364 | honestly think I'll ever like anything except the next version of Template |
365 | Toolkit better - but HTML isn't text. Zoom knows that. Do you?) |
366 | |
367 | =head2 PUTTING THE FUN INTO FUNCTIONAL |
368 | |
369 | The principle of HTML::Zoom is to provide a reusable, functional container |
370 | object that lets you build up a set of transforms to be applied; every method |
371 | call you make on a zoom object returns a new object, so it's safe to do so |
372 | on one somebody else gave you without worrying about altering state (with |
373 | the notable exception of ->next for stream objects, which I'll come to later). |
374 | |
375 | So: |
376 | |
377 | my $z2 = $z1->select('.name')->replace_content($name); |
378 | |
379 | my $z3 = $z2->select('.title')->replace_content('Ms.'); |
380 | |
381 | each time produces a new Zoom object. If you want to package up a set of |
382 | transforms to re-use, HTML::Zoom provides an 'apply' method: |
383 | |
384 | my $add_name = sub { $_->select('.name')->replace_content($name) }; |
385 | |
386 | my $same_as_z2 = $z1->apply($add_name); |
387 | |
388 | =head2 LAZINESS IS A VIRTUE |
389 | |
390 | HTML::Zoom does its best to defer doing anything until it's absolutely |
391 | required. The only point at which it descends into state is when you force |
392 | it to create a stream, directly by: |
393 | |
c9e76777 |
394 | my $stream = $zoom->to_stream; |
1c4455ae |
395 | |
396 | while (my $evt = $stream->next) { |
397 | # handle zoom event here |
398 | } |
399 | |
400 | or indirectly via: |
401 | |
402 | my $final_html = $zoom->to_html; |
403 | |
404 | my $fh = $zoom->to_fh; |
405 | |
406 | while (my $chunk = $fh->getline) { |
407 | ... |
408 | } |
409 | |
410 | Better still, the $fh returned doesn't create its stream until the first |
411 | call to getline, which means that until you call that and force it to be |
412 | stateful you can get back to the original stateless Zoom object via: |
413 | |
414 | my $zoom = $fh->to_zoom; |
415 | |
416 | which is exceedingly handy for filtering L<Plack> PSGI responses, among other |
417 | things. |
418 | |
419 | Because HTML::Zoom doesn't try and evaluate everything up front, you can |
420 | generally put things together in whatever order is most appropriate. This |
421 | means that: |
422 | |
423 | my $start = HTML::Zoom->from_html($html); |
424 | |
425 | my $zoom = $start->select('div')->replace_content('THIS IS A DIV!'); |
426 | |
427 | and: |
428 | |
429 | my $start = HTML::Zoom->select('div')->replace_content('THIS IS A DIV!'); |
430 | |
431 | my $zoom = $start->from_html($html); |
432 | |
433 | will produce equivalent final $zoom objects, thus proving that there can be |
434 | more than one way to do it without one of them being a |
435 | L<bait and switch|Switch>. |
436 | |
437 | =head2 STOCKTON TO DARLINGTON UNDER STREAM POWER |
438 | |
439 | HTML::Zoom's execution always happens in terms of streams under the hood |
440 | - that is, the basic pattern for doing anything is - |
441 | |
442 | my $stream = get_stream_from_somewhere |
443 | |
444 | while (my ($evt) = $stream->next) { |
445 | # do something with the event |
446 | } |
447 | |
448 | More importantly, all selectors and filters are also built as stream |
449 | operations, so a selector and filter pair is effectively: |
450 | |
451 | sub next { |
452 | my ($self) = @_; |
453 | my $next_evt = $self->parent_stream->next; |
454 | if ($self->selector_matches($next_evt)) { |
455 | return $self->apply_filter_to($next_evt); |
456 | } else { |
457 | return $next_evt; |
458 | } |
459 | } |
460 | |
461 | Internally, things are marginally more complicated than that, but not enough |
462 | that you as a user should normally need to care. |
463 | |
464 | In fact, an HTML::Zoom object is mostly just a container for the relevant |
465 | information from which to build the final stream that does the real work. A |
466 | stream built from a Zoom object is a stream of events from parsing the |
467 | initial HTML, wrapped in a filter stream per selector/filter pair provided |
468 | as described above. |
469 | |
470 | The upshot of this is that the application of filters works just as well on |
471 | streams as on the original Zoom object - in fact, when you run a |
472 | L</repeat_content> operation your subroutines are applied to the stream for |
473 | that element of the repeat, rather than constructing a new zoom per repeat |
474 | element as well. |
475 | |
476 | More concretely: |
477 | |
478 | $_->select('div')->replace_content('I AM A DIV!'); |
479 | |
480 | works on both HTML::Zoom objects themselves and HTML::Zoom stream objects and |
481 | shares sufficient of the implementation that you can generally forget the |
482 | difference - barring the fact that a stream already has state attached so |
483 | things like to_fh are no longer available. |
484 | |
485 | =head2 POP! GOES THE WEASEL |
486 | |
487 | ... and by Weasel, I mean layout. |
488 | |
489 | HTML::Zoom's filehandle object supports an additional event key, 'flush', |
490 | that is transparent to the rest of the system but indicates to the filehandle |
491 | object to end a getline operation at that point and return the HTML so far. |
492 | |
493 | This means that in an environment where streaming output is available, such |
494 | as a number of the L<Plack> PSGI handlers, you can add the flush key to an |
495 | event in order to ensure that the HTML generated so far is flushed through |
496 | to the browser right now. This can be especially useful if you know you're |
497 | about to call a web service or a potentially slow database query or similar |
498 | to ensure that at least the header/layout of your page renders now, improving |
499 | perceived user responsiveness while your application waits around for the |
500 | data it needs. |
501 | |
502 | This is currently exposed by the 'flush_before' option to the collect filter, |
503 | which incidentally also underlies the replace and repeat filters, so to |
504 | indicate we want this behaviour to happen before a query is executed we can |
505 | write something like: |
506 | |
507 | $zoom->select('.item')->repeat(sub { |
508 | if (my $row = $db_thing->next) { |
509 | return sub { $_->select('.item-name')->replace_content($row->name) } |
510 | } else { |
511 | return |
512 | } |
513 | }, { flush_before => 1 }); |
514 | |
515 | which should have the desired effect given a sufficiently lazy $db_thing (for |
516 | example a L<DBIx::Class::ResultSet> object). |
517 | |
518 | =head2 A FISTFUL OF OBJECTS |
519 | |
520 | At the core of an HTML::Zoom system lurks an L<HTML::Zoom::ZConfig> object, |
521 | whose purpose is to hang on to the various bits and pieces that things need |
522 | so that there's a common way of accessing shared functionality. |
523 | |
524 | Were I a computer scientist I would probably call this an "Inversion of |
525 | Control" object - which you'd be welcome to google to learn more about, or |
526 | you can just imagine a computer scientist being suspended upside down over |
527 | a pit. Either way works for me, I'm a pure maths grad. |
528 | |
529 | The ZConfig object hangs on to one each of the following for you: |
530 | |
531 | =over 4 |
532 | |
533 | =item * An HTML parser, normally L<HTML::Zoom::Parser::BuiltIn> |
534 | |
535 | =item * An HTML producer (emitter), normally L<HTML::Zoom::Producer::BuiltIn> |
536 | |
537 | =item * An object to build event filters, normally L<HTML::Zoom::FilterBuilder> |
538 | |
539 | =item * An object to parse CSS selectors, normally L<HTML::Zoom::SelectorParser> |
540 | |
541 | =item * An object to build streams, normally L<HTML::Zoom::StreamUtils> |
542 | |
543 | =back |
544 | |
545 | In theory you could replace any of these with anything you like, but in |
546 | practice you're probably best restricting yourself to subclasses, or at |
547 | least things that manage to look like the original if you squint a bit. |
548 | |
549 | If you do something more clever than that, or find yourself overriding things |
550 | in your ZConfig a lot, please please tell us about it via one of the means |
551 | mentioned under L</SUPPORT>. |
552 | |
553 | =head2 SEMANTIC DIDACTIC |
554 | |
555 | Some will argue that overloading CSS selectors to do data stuff is a terrible |
556 | idea, and possibly even a step towards the "Concrete Javascript" pattern |
557 | (which I abhor) or Smalltalk's Morphic (which I ignore, except for the part |
558 | where it keeps reminding me of the late, great Tony Hart's plasticine friend). |
559 | |
560 | To which I say, "eh", "meh", and possibly also "feh". If it really upsets |
561 | you, either use extra classes for this (and remove them afterwards) or |
562 | use special fake elements or, well, honestly, just use something different. |
563 | L<Template::Semantic> provides a similar idea to zoom except using XPath |
564 | and XML::LibXML transforms rather than a lightweight streaming approach - |
565 | maybe you'd like that better. Or maybe you really did want |
566 | L<Template Toolkit|Template> after all. It is still damn good at what it does, |
567 | after all. |
568 | |
569 | So far, however, I've found that for new sites the designers I'm working with |
570 | generally want to produce nice semantic HTML with classes that represent the |
571 | nature of the data rather than the structure of the layout, so sharing them |
572 | as a common interface works really well for us. |
573 | |
574 | In the absence of any evidence that overloading CSS selectors has killed |
575 | children or unexpectedly set fire to grandmothers - and given microformats |
576 | have been around for a while there's been plenty of opportunity for |
577 | octagenarian combustion - I'd suggest you give it a try and see if you like it. |
578 | |
579 | =head2 GET THEE TO A SUMMARY! |
580 | |
581 | Erm. Well. |
582 | |
583 | HTML::Zoom is a lazy, stream oriented, streaming capable, mostly functional, |
584 | CSS selector based semantic templating engine for HTML and HTML-like |
585 | document formats. |
586 | |
587 | But I said that already. Although hopefully by now you have some idea what I |
588 | meant when I said it. If you didn't have any idea the first time. I mean, I'm |
589 | not trying to call you stupid or anything. Just saying that maybe it wasn't |
590 | totally obvious without the explanation. Or something. |
591 | |
592 | Er. |
593 | |
594 | Maybe we should just move on to the method docs. |
595 | |
596 | =head1 METHODS |
597 | |
598 | =head2 new |
599 | |
600 | my $zoom = HTML::Zoom->new; |
601 | |
602 | my $zoom = HTML::Zoom->new({ zconfig => $zconfig }); |
603 | |
604 | Create a new empty Zoom object. You can optionally pass an |
605 | L<HTML::Zoom::ZConfig> instance if you're trying to override one or more of |
606 | the default components. |
607 | |
608 | This method isn't often used directly since several other methods can also |
609 | act as constructors, notable L</select> and L</from_html> |
610 | |
611 | =head2 zconfig |
612 | |
613 | my $zconfig = $zoom->zconfig; |
614 | |
615 | Retrieve the L<HTML::Zoom::ZConfig> instance used by this Zoom object. You |
616 | shouldn't usually need to call this yourself. |
617 | |
618 | =head2 from_html |
619 | |
620 | my $zoom = HTML::Zoom->from_html($html); |
621 | |
622 | my $z2 = $z1->from_html($html); |
623 | |
624 | Parses the HTML using the current zconfig's parser object and returns a new |
625 | zoom instance with that as the source HTML to be transformed. |
626 | |
627 | =head2 from_file |
628 | |
629 | my $zoom = HTML::Zoom->from_file($file); |
630 | |
631 | my $z2 = $z1->from_file($file); |
632 | |
633 | Convenience method - slurps the contents of $file and calls from_html with it. |
634 | |
f3a758ad |
635 | =head2 from_events |
636 | |
637 | my $zoom = HTML::Zoom->from_events($evt); |
638 | |
639 | Create a new Zoom object from collected events |
640 | |
1c4455ae |
641 | =head2 to_stream |
642 | |
643 | my $stream = $zoom->to_stream; |
644 | |
645 | while (my ($evt) = $stream->next) { |
646 | ... |
647 | |
648 | Creates a stream, starting with a stream of the events from the HTML supplied |
649 | via L</from_html> and then wrapping it in turn with each selector+filter pair |
650 | that have been applied to the zoom object. |
651 | |
652 | =head2 to_fh |
653 | |
654 | my $fh = $zoom->to_fh; |
655 | |
656 | call_something_expecting_a_filehandle($fh); |
657 | |
658 | Returns an L<HTML::Zoom::ReadFH> instance that will create a stream the first |
659 | time its getline method is called and then return all HTML up to the next |
660 | event with 'flush' set. |
661 | |
662 | You can pass this filehandle to compliant PSGI handlers (and probably most |
663 | web frameworks). |
664 | |
665 | =head2 run |
666 | |
667 | $zoom->run; |
668 | |
669 | Runs the zoom object's transforms without doing anything with the results. |
670 | |
671 | Normally used to get side effects of a zoom run - for example when using |
672 | L<HTML::Zoom::FilterBuilder/collect> to slurp events for scraping or layout. |
673 | |
674 | =head2 apply |
675 | |
676 | my $z2 = $z1->apply(sub { |
677 | $_->select('div')->replace_content('I AM A DIV!') }) |
678 | }); |
679 | |
680 | Sets $_ to the zoom object and then runs the provided code. Basically syntax |
681 | sugar, the following is entirely equivalent: |
682 | |
683 | my $sub = sub { |
684 | shift->select('div')->replace_content('I AM A DIV!') }) |
685 | }; |
686 | |
687 | my $z2 = $sub->($z1); |
688 | |
3959a04d |
689 | =head2 apply_if |
690 | |
691 | my $z2 = $z1->apply_if($cond, sub { |
692 | $_->select('div')->replace_content('I AM A DIV!') }) |
693 | }); |
694 | |
695 | ->apply but will only run the tranform if $cond is true |
696 | |
1c4455ae |
697 | =head2 to_html |
698 | |
699 | my $html = $zoom->to_html; |
700 | |
701 | Runs the zoom processing and returns the resulting HTML. |
702 | |
703 | =head2 memoize |
704 | |
705 | my $z2 = $z1->memoize; |
706 | |
707 | Creates a new zoom whose source HTML is the results of the original zoom's |
708 | processing. Effectively syntax sugar for: |
709 | |
710 | my $z2 = HTML::Zoom->from_html($z1->to_html); |
711 | |
712 | but preserves your L<HTML::Zoom::ZConfig> object. |
713 | |
714 | =head2 with_filter |
715 | |
716 | my $zoom = HTML::Zoom->with_filter( |
717 | 'div', $filter_builder->replace_content('I AM A DIV!') |
718 | ); |
719 | |
720 | my $z2 = $z1->with_filter( |
721 | 'div', $filter_builder->replace_content('I AM A DIV!') |
722 | ); |
723 | |
724 | Lower level interface than L</select> to adding filters to your zoom object. |
725 | |
726 | In normal usage, you probably don't need to call this yourself. |
727 | |
728 | =head2 select |
729 | |
730 | my $zoom = HTML::Zoom->select('div')->replace_content('I AM A DIV!'); |
731 | |
732 | my $z2 = $z1->select('div')->replace_content('I AM A DIV!'); |
733 | |
97192b02 |
734 | Returns an intermediary object of the class L<HTML::Zoom::TransformBuilder> |
1c4455ae |
735 | on which methods of your L<HTML::Zoom::FilterBuilder> object can be called. |
736 | |
737 | In normal usage you should generally always put the pair of method calls |
738 | together; the intermediary object isn't designed or expected to stick around. |
739 | |
740 | =head2 then |
741 | |
2daa653a |
742 | my $z2 = $z1->select('div')->add_to_attribute(class => 'spoon') |
1c4455ae |
743 | ->then |
744 | ->replace_content('I AM A DIV!'); |
745 | |
746 | Re-runs the previous select to allow you to chain actions together on the |
747 | same selector. |
748 | |
94a3ddd9 |
749 | =head1 AUTOLOAD METHODS |
750 | |
751 | L<HTML::Zoom> AUTOLOADS methods against L</select> so that you can reduce a |
752 | certain amount of boilerplate typing. This allows you to replace: |
753 | |
754 | $z->select('div')->replace_content("Hello World"); |
755 | |
756 | With: |
757 | |
758 | $z->replace_content(div => "Hello World"); |
759 | |
760 | Besides saving a few keys per invocations, you may feel this looks neater |
761 | in your code and increases understanding. |
762 | |
f107bef7 |
763 | =head1 AUTHOR |
45b4cea1 |
764 | |
f107bef7 |
765 | mst - Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk> |
45b4cea1 |
766 | |
f107bef7 |
767 | =head1 CONTRIBUTORS |
45b4cea1 |
768 | |
f107bef7 |
769 | Oliver Charles |
770 | |
771 | Jakub Nareski |
772 | |
773 | Simon Elliot |
774 | |
775 | Joe Highton |
776 | |
777 | John Napiorkowski |
778 | |
5cac799e |
779 | Robert Buels |
780 | |
b0ed2859 |
781 | David Dorward |
782 | |
f107bef7 |
783 | =head1 COPYRIGHT |
784 | |
785 | Copyright (c) 2010-2011 the HTML::Zoom L</AUTHOR> and L</CONTRIBUTORS> |
786 | as listed above. |
45b4cea1 |
787 | |
788 | =head1 LICENSE |
789 | |
790 | This library is free software, you can redistribute it and/or modify |
791 | it under the same terms as Perl itself. |
792 | |
d80786d0 |
793 | =cut |
45b4cea1 |
794 | |