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1 package HTML::Element::Library;
2 use strict;
3 use warnings;
4
5 our $VERSION = '5.200_002';
6 our $DEBUG = 0;
7
8 use Array::Group ':all';
9 use Carp 'confess';
10 use Data::Dumper;
11 use Data::Rmap 'rmap_array';
12 use HTML::Element;
13 use HTML::FillInForm;
14 use List::MoreUtils ':all';
15 use List::Rotation::Cycle;
16 use List::Util 'first';
17 use Params::Validate ':all';
18 use Scalar::Listify;
19
20 # https://rt.cpan.org/Ticket/Display.html?id=44105
21 sub HTML::Element::fillinform {
22 my ($tree, $hashref, $return_tree, $guts) = @_;
23 (ref $hashref) eq 'HASH' or confess 'hashref not supplied as argument' ;
24
25 my $html = $tree->as_HTML;
26 my $new_html = HTML::FillInForm->fill(\$html, $hashref);
27
28 if ($return_tree) {
29 $tree = HTML::TreeBuilder->new_from_content($new_html);
30 $tree = $guts ? $tree->guts : $tree ;
31 } else {
32 $new_html;
33 }
34 }
35
36 sub HTML::Element::siblings {
37 my $element = shift;
38 my $p = $element->parent;
39 return () unless $p;
40 $p->content_list;
41 }
42
43 sub HTML::Element::defmap {
44 my($tree, $attr, $hashref, $debug) = @_;
45
46 while (my ($k, $v) = (each %$hashref)) {
47 warn "defmap looks for ($attr => $k)" if $debug;
48 my $found = $tree->look_down($attr => $k);
49 if ($found) {
50 warn "($attr => $k) was found.. replacing with '$v'" if $debug;
51 $found->replace_content( $v );
52 }
53 }
54 }
55
56 sub HTML::Element::_only_empty_content {
57 my ($self) = @_;
58 my @c = $self->content_list;
59 my $length = scalar @c;
60
61 scalar @c == 1 and not length $c[0];
62 }
63
64 sub HTML::Element::prune {
65 my ($self) = @_;
66
67 for my $c ($self->content_list) {
68 next unless ref $c;
69 $c->prune;
70 }
71
72 # post-order:
73 $self->delete if ($self->is_empty or $self->_only_empty_content);
74 $self;
75 }
76
77 sub HTML::Element::newchild {
78 my ($lol, $parent_label, @newchild) = @_;
79 rmap_array {
80 if ($_->[0] eq $parent_label) {
81 $_ = [ $parent_label => @newchild ];
82 Data::Rmap::cut($_);
83 } else {
84 $_;
85 }
86 } $lol;
87 }
88
89 sub HTML::Element::crunch { ## no critic (RequireArgUnpacking)
90 my $container = shift;
91
92 my %p = validate(@_, {
93 look_down => { type => ARRAYREF },
94 leave => { default => 1 },
95 });
96
97 my @look_down = @{$p{look_down}} ;
98 my @elem = $container->look_down(@look_down) ;
99
100 my $detached;
101
102 for my $elem (@elem) {
103 $elem->detach if $detached++ >= $p{leave};
104 }
105 }
106
107 sub HTML::Element::hash_map { ## no critic (RequireArgUnpacking)
108 my $container = shift;
109
110 my %p = validate(@_, {
111 hash => { type => HASHREF },
112 to_attr => 1,
113 excluding => { type => ARRAYREF , default => [] },
114 debug => { default => 0 },
115 });
116
117 warn 'The container tag is ', $container->tag if $p{debug} ;
118 warn 'hash' . Dumper($p{hash}) if $p{debug} ;
119 #warn 'at_under' . Dumper(\@_) if $p{debug} ;
120
121 my @same_as = $container->look_down( $p{to_attr} => qr/.+/s ) ;
122
123 warn 'Found ' . scalar(@same_as) . ' nodes' if $p{debug} ;
124
125 for my $same_as (@same_as) {
126 my $attr_val = $same_as->attr($p{to_attr}) ;
127 if (first { $attr_val eq $_ } @{$p{excluding}}) {
128 warn "excluding $attr_val" if $p{debug} ;
129 next;
130 }
131 warn "processing $attr_val" if $p{debug} ;
132 $same_as->replace_content($p{hash}->{$attr_val});
133 }
134 }
135
136 sub HTML::Element::hashmap {
137 my ($container, $attr_name, $hashref, $excluding, $debug) = @_;
138
139 $excluding ||= [] ;
140
141 $container->hash_map(
142 hash => $hashref,
143 to_attr => $attr_name,
144 excluding => $excluding,
145 debug => $debug);
146 }
147
148
149 sub HTML::Element::passover {
150 my ($tree, @to_preserve) = @_;
151
152 warn "ARGS: my ($tree, @to_preserve)" if $DEBUG;
153 warn $tree->as_HTML(undef, ' ') if $DEBUG;
154
155 my $exodus = $tree->look_down(id => $to_preserve[0]);
156
157 warn "E: $exodus" if $DEBUG;
158
159 my @s = HTML::Element::siblings($exodus);
160
161 for my $s (@s) {
162 next unless ref $s;
163 $s->delete unless first { $s->attr('id') eq $_ } @to_preserve;
164 }
165
166 return $exodus; # Goodbye Egypt! http://en.wikipedia.org/wiki/Passover
167 }
168
169 sub HTML::Element::sibdex {
170 my $element = shift;
171 firstidx { $_ eq $element } $element->siblings
172 }
173
174 sub HTML::Element::addr { goto &HTML::Element::sibdex }
175
176 sub HTML::Element::replace_content {
177 my $elem = shift;
178 $elem->delete_content;
179 $elem->push_content(@_);
180 }
181
182 sub HTML::Element::wrap_content {
183 my($self, $wrap) = @_;
184 my $content = $self->content;
185 if (ref $content) {
186 $wrap->push_content(@$content);
187 @$content = ($wrap);
188 }
189 else {
190 $self->push_content($wrap);
191 }
192 $wrap;
193 }
194
195 sub HTML::Element::Library::super_literal {
196 my($text) = @_;
197 HTML::Element->new('~literal', text => $text);
198 }
199
200 sub HTML::Element::position {
201 # Report coordinates by chasing addr's up the
202 # HTML::ElementSuper tree. We know we've reached
203 # the top when a) there is no parent, or b) the
204 # parent is some HTML::Element unable to report
205 # it's position.
206 my $p = shift;
207 my @pos;
208 while ($p) {
209 my $a = $p->addr;
210 unshift @pos, $a if defined $a;
211 $p = $p->parent;
212 }
213 @pos;
214 }
215
216 sub HTML::Element::content_handler {
217 my ($tree, %content_hash) = @_;
218
219 for my $k (keys %content_hash) {
220 $tree->set_child_content(id => $k, $content_hash{$k});
221 }
222 }
223
224 sub HTML::Element::assign { goto &HTML::Element::content_handler }
225
226 sub make_counter {
227 my $i = 1;
228 sub {
229 shift() . ':' . $i++
230 }
231 }
232
233 sub HTML::Element::iter {
234 my ($tree, $p, @data) = @_;
235
236 # warn 'P: ' , $p->attr('id') ;
237 # warn 'H: ' , $p->as_HTML;
238
239 # my $id_incr = make_counter;
240 my @item = map {
241 my $new_item = clone $p;
242 $new_item->replace_content($_);
243 $new_item;
244 } @data;
245
246 $p->replace_with(@item);
247 }
248
249 sub HTML::Element::iter2 { ## no critic (RequireArgUnpacking)
250 my $tree = shift;
251
252 #warn "INPUT TO TABLE2: ", Dumper \@_;
253
254 my %p = validate(
255 @_, {
256 wrapper_ld => { default => ['_tag' => 'dl'] },
257 wrapper_data => 1,
258 wrapper_proc => { default => undef },
259 item_ld => {
260 default => sub {
261 my $tr = shift;
262 [
263 $tr->look_down('_tag' => 'dt'),
264 $tr->look_down('_tag' => 'dd')
265 ];
266 }},
267 item_data => {
268 default => sub {
269 my ($wrapper_data) = @_;
270 shift @{$wrapper_data};
271 }},
272 item_proc => {
273 default => sub {
274 my ($item_elems, $item_data, $row_count) = @_;
275 $item_elems->[$_]->replace_content($item_data->[$_]) for (0,1) ;
276 $item_elems;
277 }},
278 splice => {
279 default => sub {
280 my ($container, @item_elems) = @_;
281 $container->splice_content(0, 2, @item_elems);
282 }
283 },
284 debug => {default => 0}
285 }
286 );
287
288 warn 'wrapper_data: ' . Dumper $p{wrapper_data} if $p{debug} ;
289
290 my $container = ref_or_ld($tree, $p{wrapper_ld});
291 warn 'container: ' . $container if $p{debug} ;
292 warn 'wrapper_(preproc): ' . $container->as_HTML if $p{debug} ;
293 $p{wrapper_proc}->($container) if defined $p{wrapper_proc} ;
294 warn 'wrapper_(postproc): ' . $container->as_HTML if $p{debug} ;
295
296 my $_item_elems = $p{item_ld}->($container);
297
298 my $row_count;
299 my @item_elem;
300 while(1){
301 my $item_data = $p{item_data}->($p{wrapper_data});
302 last unless defined $item_data;
303
304 warn Dumper('item_data', $item_data) if $p{debug};
305
306 my $item_elems = [ map { $_->clone } @{$_item_elems} ] ;
307
308 if ($p{debug}) {
309 for (@{$item_elems}) {
310 warn 'ITEM_ELEMS ', $_->as_HTML if $p{debug};
311 }
312 }
313
314 my $new_item_elems = $p{item_proc}->($item_elems, $item_data, ++$row_count);
315
316 if ($p{debug}) {
317 for (@{$new_item_elems}) {
318 warn 'NEWITEM_ELEMS ', $_->as_HTML if $p{debug};
319 }
320 }
321
322 push @item_elem, @{$new_item_elems} ;
323 }
324
325 warn 'pushing ' . @item_elem . ' elems' if $p{debug} ;
326
327 $p{splice}->($container, @item_elem);
328 }
329
330 sub HTML::Element::dual_iter {
331 my ($parent, $data) = @_;
332
333 my ($prototype_a, $prototype_b) = $parent->content_list;
334
335 # my $id_incr = make_counter;
336
337 my $i;
338
339 @$data %2 == 0 or confess 'dataset does not contain an even number of members';
340
341 my @iterable_data = ngroup 2 => @$data;
342
343 my @item = map {
344 my ($new_a, $new_b) = map { clone $_ } ($prototype_a, $prototype_b) ;
345 $new_a->splice_content(0,1, $_->[0]);
346 $new_b->splice_content(0,1, $_->[1]);
347 #$_->attr('id', $id_incr->($_->attr('id'))) for ($new_a, $new_b) ;
348 ($new_a, $new_b)
349 } @iterable_data;
350
351 $parent->splice_content(0, 2, @item);
352 }
353
354 sub HTML::Element::set_child_content { ## no critic (RequireArgUnpacking)
355 my $tree = shift;
356 my $content = pop;
357 my @look_down = @_;
358
359 my $content_tag = $tree->look_down(@look_down);
360
361 unless ($content_tag) {
362 warn "criteria [@look_down] not found";
363 return;
364 }
365
366 $content_tag->replace_content($content);
367 }
368
369 sub HTML::Element::highlander {
370 my ($tree, $local_root_id, $aref, @arg) = @_;
371
372 ref $aref eq 'ARRAY' or confess 'must supply array reference';
373
374 my @aref = @$aref;
375 @aref % 2 == 0 or confess 'supplied array ref must have an even number of entries';
376
377 warn __PACKAGE__ if $DEBUG;
378
379 my $survivor;
380 while (my ($id, $test) = splice @aref, 0, 2) {
381 warn $id if $DEBUG;
382 if ($test->(@arg)) {
383 $survivor = $id;
384 last;
385 }
386 }
387
388 my @id_survivor = (id => $survivor);
389 my $survivor_node = $tree->look_down(@id_survivor);
390 # warn $survivor;
391 # warn $local_root_id;
392 # warn $node;
393
394 warn "survivor: $survivor" if $DEBUG;
395 warn 'tree: ' . $tree->as_HTML if $DEBUG;
396
397 $survivor_node or die "search for @id_survivor failed in tree($tree): " . $tree->as_HTML;
398
399 my $survivor_node_parent = $survivor_node->parent;
400 $survivor_node = $survivor_node->clone;
401 $survivor_node_parent->replace_content($survivor_node);
402
403 warn 'new tree: ' . $tree->as_HTML if $DEBUG;
404
405 $survivor_node;
406 }
407
408 sub HTML::Element::highlander2 { ## no critic (RequireArgUnpacking)
409 my $tree = shift;
410
411 my %p = validate(@_, {
412 cond => { type => ARRAYREF },
413 cond_arg => {
414 type => ARRAYREF,
415 default => []
416 },
417 debug => { default => 0 }
418 });
419
420 my @cond = @{$p{cond}};
421 @cond % 2 == 0 or confess 'supplied array ref must have an even number of entries';
422
423 warn __PACKAGE__ if $p{debug};
424
425 my @cond_arg = @{$p{cond_arg}};
426
427 my $survivor; my $then;
428 while (my ($id, $if_then) = splice @cond, 0, 2) {
429 warn $id if $p{debug};
430 my ($if, $_then);
431
432 if (ref $if_then eq 'ARRAY') {
433 ($if, $_then) = @$if_then;
434 } else {
435 ($if, $_then) = ($if_then, sub {});
436 }
437
438 if ($if->(@cond_arg)) {
439 $survivor = $id;
440 $then = $_then;
441 last;
442 }
443 }
444
445 my @ld = (ref $survivor eq 'ARRAY') ? @$survivor : (id => $survivor);
446
447 warn 'survivor: ', $survivor if $p{debug};
448 warn 'survivor_ld: ', Dumper \@ld if $p{debug};
449
450 my $survivor_node = $tree->look_down(@ld);
451
452 $survivor_node or confess "search for @ld failed in tree($tree): " . $tree->as_HTML;
453
454 my $survivor_node_parent = $survivor_node->parent;
455 $survivor_node = $survivor_node->clone;
456 $survivor_node_parent->replace_content($survivor_node);
457
458 # **************** NEW FUNCTIONALITY *******************
459 # apply transforms on survivor node
460
461 warn 'SURV::pre_trans ' . $survivor_node->as_HTML if $p{debug};
462 $then->($survivor_node, @cond_arg);
463 warn 'SURV::post_trans ' . $survivor_node->as_HTML if $p{debug};
464 # **************** NEW FUNCTIONALITY *******************
465
466 $survivor_node;
467 }
468
469 sub overwrite_action {
470 my ($mute_node, %X) = @_;
471
472 $mute_node->attr($X{local_attr}{name} => $X{local_attr}{value}{new});
473 }
474
475 sub HTML::Element::overwrite_attr {
476 my $tree = shift;
477
478 $tree->mute_elem(@_, \&overwrite_action);
479 }
480
481 sub HTML::Element::mute_elem {
482 my ($tree, $mute_attr, $closures, $post_hook) = @_;
483
484 my @mute_node = $tree->look_down($mute_attr => qr/.*/s) ;
485
486 for my $mute_node (@mute_node) {
487 my ($local_attr,$mute_key) = split /\s+/s, $mute_node->attr($mute_attr);
488 my $local_attr_value_current = $mute_node->attr($local_attr);
489 my $local_attr_value_new = $closures->{$mute_key}->($tree, $mute_node, $local_attr_value_current);
490 $post_hook->(
491 $mute_node,
492 tree => $tree,
493 local_attr => {
494 name => $local_attr,
495 value => {
496 current => $local_attr_value_current,
497 new => $local_attr_value_new
498 }
499 }
500 ) if ($post_hook) ;
501 }
502 }
503
504
505
506 sub HTML::Element::table {
507 my ($s, %table) = @_;
508 my $table = {};
509
510 # Get the table element
511 $table->{table_node} = $s->look_down(id => $table{gi_table});
512 $table->{table_node} or confess "table tag not found via (id => $table{gi_table}";
513
514 # Get the prototype tr element(s)
515 my @table_gi_tr = listify $table{gi_tr} ;
516 my @iter_node = map {
517 my $tr = $table->{table_node}->look_down(id => $_);
518 $tr or confess "tr with id => $_ not found";
519 $tr;
520 } @table_gi_tr;
521
522 warn 'found ' . @iter_node . ' iter nodes ' if $DEBUG;
523 my $iter_node = List::Rotation::Cycle->new(@iter_node);
524
525 # warn $iter_node;
526 warn Dumper ($iter_node, \@iter_node) if $DEBUG;
527
528 # $table->{content} = $table{content};
529 # $table->{parent} = $table->{table_node}->parent;
530
531 # $table->{table_node}->detach;
532 # $_->detach for @iter_node;
533
534 my @table_rows;
535
536 while (1) {
537 my $row = $table{tr_data}->($table, $table{table_data});
538 last unless defined $row;
539
540 # get a sample table row and clone it.
541 my $I = $iter_node->next;
542 warn "I: $I" if $DEBUG;
543 my $new_iter_node = $I->clone;
544
545 $table{td_data}->($new_iter_node, $row);
546 push @table_rows, $new_iter_node;
547 }
548
549 if (@table_rows) {
550 my $replace_with_elem = $s->look_down(id => shift @table_gi_tr) ;
551 $s->look_down(id => $_)->detach for @table_gi_tr;
552 $replace_with_elem->replace_with(@table_rows);
553 }
554 }
555
556 sub ref_or_ld {
557 my ($tree, $slot) = @_;
558
559 if (ref($slot) eq 'CODE') {
560 $slot->($tree);
561 } else {
562 $tree->look_down(@$slot);
563 }
564 }
565
566 sub HTML::Element::table2 { ## no critic (RequireArgUnpacking)
567 my $tree = shift;
568
569 my %p = validate(
570 @_, {
571 table_ld => { default => ['_tag' => 'table'] },
572 table_data => 1,
573 table_proc => { default => undef },
574 tr_ld => { default => ['_tag' => 'tr'] },
575 tr_data => {
576 default => sub {
577 my ($self, $data) = @_;
578 shift @{$data};
579 }},
580 tr_base_id => { default => undef },
581 tr_proc => { default => sub {} },
582 td_proc => 1,
583 debug => {default => 0}
584 }
585 );
586
587 warn 'INPUT TO TABLE2: ', Dumper \@_ if $p{debug};
588 warn 'table_data: ' . Dumper $p{table_data} if $p{debug} ;
589
590 my $table = {};
591
592 # Get the table element
593 $table->{table_node} = ref_or_ld( $tree, $p{table_ld} ) ;
594 $table->{table_node} or confess 'table tag not found via ' . Dumper($p{table_ld}) ;
595
596 warn 'table: ' . $table->{table_node}->as_HTML if $p{debug};
597
598 # Get the prototype tr element(s)
599 my @proto_tr = ref_or_ld( $table->{table_node}, $p{tr_ld} ) ;
600
601 warn 'found ' . @proto_tr . ' iter nodes' if $p{debug};
602
603 return unless @proto_tr;
604
605 if ($p{debug}) {
606 warn $_->as_HTML for @proto_tr;
607 }
608 my $proto_tr = List::Rotation::Cycle->new(@proto_tr);
609
610 my $tr_parent = $proto_tr[0]->parent;
611 warn 'parent element of trs: ' . $tr_parent->as_HTML if $p{debug};
612
613 my $row_count;
614
615 my @table_rows;
616
617 while(1) {
618 my $row = $p{tr_data}->($table, $p{table_data}, $row_count);
619 warn 'data row: ' . Dumper $row if $p{debug};
620 last unless defined $row;
621
622 # wont work: my $new_iter_node = $table->{iter_node}->clone;
623 my $new_tr_node = $proto_tr->next->clone;
624 warn "new_tr_node: $new_tr_node" if $p{debug};
625
626 $p{tr_proc}->($tree, $new_tr_node, $row, $p{tr_base_id}, ++$row_count) if defined $p{tr_proc};
627
628 warn 'data row redux: ' . Dumper $row if $p{debug};
629
630 $p{td_proc}->($new_tr_node, $row);
631 push @table_rows, $new_tr_node;
632 }
633
634 $_->detach for @proto_tr;
635
636 $tr_parent->push_content(@table_rows) if (@table_rows) ;
637 }
638
639 sub HTML::Element::unroll_select {
640 my ($s, %select) = @_;
641
642 my $select = {};
643 warn 'Select Hash: ' . Dumper(\%select) if $select{debug};
644
645 my $select_node = $s->look_down(id => $select{select_label});
646 warn "Select Node: $select_node" if $select{debug};
647
648 unless ($select{append}) {
649 for my $option ($select_node->look_down('_tag' => 'option')) {
650 $option->delete;
651 }
652 }
653
654 my $option = HTML::Element->new('option');
655 warn "Option Node: $option" if $select{debug};
656
657 $option->detach;
658
659 while (my $row = $select{data_iter}->($select{data})) {
660 warn 'Data Row: ' . Dumper($row) if $select{debug};
661 my $o = $option->clone;
662 $o->attr('value', $select{option_value}->($row));
663 $o->attr('SELECTED', 1) if (exists $select{option_selected} and $select{option_selected}->($row));
664
665 $o->replace_content($select{option_content}->($row));
666 $select_node->push_content($o);
667 warn $o->as_HTML if $select{debug};
668 }
669 }
670
671 sub HTML::Element::set_sibling_content {
672 my ($elt, $content) = @_;
673
674 $elt->parent->splice_content($elt->pindex + 1, 1, $content);
675 }
676
677 sub HTML::TreeBuilder::parse_string {
678 my ($package, $string) = @_;
679
680 my $h = HTML::TreeBuilder->new;
681 HTML::TreeBuilder->parse($string);
682 }
683
684 1;
685 __END__
686
687 =encoding utf-8
688
689 =head1 NAME
690
691 HTML::Element::Library - HTML::Element convenience functions
692
693 =head1 SYNOPSIS
694
695 use HTML::Element::Library;
696 use HTML::TreeBuilder;
697
698 =head1 DESCRIPTION
699
700 HTML:::Element::Library provides extra methods for HTML::Element.
701
702 =head1 METHODS
703
704 =head2 Positional Querying Methods
705
706 =head3 $elem->siblings
707
708 Return a list of all nodes under the same parent.
709
710 =head3 $elem->sibdex
711
712 Return the index of C<$elem> into the array of siblings of which it is
713 a part. L<HTML::ElementSuper> calls this method C<addr> but I don't
714 think that is a descriptive name. And such naming is deceptively close
715 to the C<address> function of C<HTML::Element>. HOWEVER, in the
716 interest of backwards compatibility, both methods are available.
717
718 =head3 $elem->addr
719
720 Same as sibdex
721
722 =head3 $elem->position()
723
724 Returns the coordinates of this element in the tree it inhabits. This
725 is accomplished by succesively calling addr() on ancestor elements
726 until either a) an element that does not support these methods is
727 found, or b) there are no more parents. The resulting list is the
728 n-dimensional coordinates of the element in the tree.
729
730 =head2 Element Decoration Methods
731
732 =head3 HTML::Element::Library::super_literal($text)
733
734 In L<HTML::Element>, Sean Burke discusses super-literals. They are
735 text which does not get escaped. Great for includng Javascript in
736 HTML. Also great for including foreign language into a document.
737
738 So, you basically toss C<super_literal> your text and back comes your
739 text wrapped in a C<~literal> element.
740
741 One of these days, I'll around to writing a nice C<EXPORT> section.
742
743 =head2 Tree Rewriting Methods
744
745 =head3 "de-prepping" HTML
746
747 Oftentimes, the HTML to be worked with will have multiple sample rows:
748
749 <OL>
750 <LI>bread
751 <LI>butter
752 <LI>beer
753 <LI>bacon
754 </OL>
755
756 But, before you begin to rewrite the HTML with your model data, you
757 typically only want 1 or 2 sample rows.
758
759 Thus, you want to "crunch" the multiple sample rows to a specified
760 amount. Hence the C<crunch> method:
761
762 $tree->crunch(look_down => [ '_tag' => 'li' ], leave => 2) ;
763
764 The C<leave> argument defaults to 1 if not given. The call above would
765 "crunch" the above 4 sample rows to:
766
767 <OL>
768 <LI>bread
769 <LI>butter
770 </OL>
771
772 =head3 Simplifying calls to HTML::FillInForm
773
774 Since HTML::FillInForm gets and returns strings, using HTML::Element
775 instances becomes tedious:
776
777 1. Seamstress has an HTML tree that it wants the form filled in on
778 2. Seamstress converts this tree to a string
779 3. FillInForm parses the string into an HTML tree and then fills in the form
780 4. FillInForm converts the HTML tree to a string
781 5. Seamstress re-parses the HTML for additional processing
782
783 I've filed a bug about this:
784 L<https://rt.cpan.org/Ticket/Display.html?id=44105>
785
786 This function, fillinform, allows you to pass a tree to fillinform
787 (along with your data structure) and get back a tree:
788
789 my $new_tree = $html_tree->fillinform($data_structure);
790
791 =head3 Mapping a hashref to HTML elements
792
793 It is very common to get a hashref of data from some external source -
794 flat file, database, XML, etc. Therefore, it is important to have a
795 convenient way of mapping this data to HTML.
796
797 As it turns out, there are 3 ways to do this in
798 HTML::Element::Library. The most strict and structured way to do this
799 is with C<content_handler>. Two other methods, C<hashmap> and
800 C<datamap> require less manual mapping and may prove even more easy to
801 use in certain cases.
802
803 As is usual with Perl, a practical example is always best. So let's
804 take some sample HTML:
805
806 <h1>user data</h1>
807 <span id="name">?</span>
808 <span id="email">?</span>
809 <span id="gender">?</span>
810
811 Now, let's say our data structure is this:
812
813 $ref = { email => 'jim@beam.com', gender => 'lots' } ;
814
815 And let's start with the most strict way to get what you want:
816
817 $tree->content_handler(email => $ref->{email} , gender => $ref->{gender}) ;
818
819 In this case, you manually state the mapping between id tags and
820 hashref keys and then C<content_handler> retrieves the hashref data
821 and pops it in the specified place.
822
823 Now let's look at the two (actually 2 and a half) other hash-mapping
824 methods.
825
826 $tree->hashmap(id => $ref);
827
828 Now, what this function does is super-destructive. It finds every
829 element in the tree with an attribute named id (since 'id' is a
830 parameter, it could find every element with some other attribute also)
831 and replaces the content of those elements with the hashref value.
832
833 So, in the case above, the
834
835 <span id="name">?</span>
836
837 would come out as
838
839 <span id="name"></span>
840
841 (it would be blank) - because there is nothing in the hash with that
842 value, so it substituted
843
844 $ref->{name}
845
846 which was blank and emptied the contents.
847
848 Now, let's assume we want to protect name from being auto-assigned.
849 Here is what you do:
850
851 $tree->hashmap(id => $ref, ['name']);
852
853 That last array ref is an exclusion list.
854
855 But wouldnt it be nice if you could do a hashmap, but only assigned
856 things which are defined in the hashref? C<< defmap() >> to the
857 rescue:
858
859 $tree->defmap(id => $ref);
860
861 does just that, so
862
863 <span id="name">?</span>
864
865 would be left alone.
866
867 =head4 $elem->hashmap($attr_name, \%hashref, \@excluded, $debug)
868
869 This method is designed to take a hashref and populate a series of
870 elements. For example:
871
872 <table>
873 <tr sclass="tr" class="alt" align="left" valign="top">
874 <td smap="people_id">1</td>
875 <td smap="phone">(877) 255-3239</td>
876 <td smap="password">*********</td>
877 </tr>
878 </table>
879
880 In the table above, there are several attributes named C<< smap >>. If
881 we have a hashref whose keys are the same:
882
883 my %data = (people_id => 888, phone => '444-4444', password => 'dont-you-dare-render');
884
885 Then a single API call allows us to populate the HTML while excluding
886 those ones we dont:
887
888 $tree->hashmap(smap => \%data, ['password']);
889
890 Note: the other way to prevent rendering some of the hash mapping is
891 to not give that element the attr you plan to use for hash mapping.
892
893 Also note: the function C<< hashmap >> has a simple easy-to-type API.
894 Interally, it calls C<< hash_map >> (which has a more verbose keyword
895 calling API). Thus, the above call to C<hashmap()> results in this
896 call:
897
898 $tree->hash_map(hash => \%data, to_attr => 'sid', excluding => ['password']);
899
900 =head4 $elem->defmap($attr_name, \%hashref, $debug)
901
902 C<defmap> was described above.
903
904 =head3 $elem->replace_content(@new_elem)
905
906 Replaces all of C<$elem>'s content with C<@new_elem>.
907
908 =head3 $elem->wrap_content($wrapper_element)
909
910 Wraps the existing content in the provided element. If the provided
911 element happens to be a non-element, a push_content is performed
912 instead.
913
914 =head3 $elem->set_child_content(@look_down, $content)
915
916 This method looks down $tree using the criteria specified in
917 @look_down using the the HTML::Element look_down() method.
918
919 After finding the node, it detaches the node's content and pushes
920 $content as the node's content.
921
922 =head3 $tree->content_handler(%id_content)
923
924 This is a convenience method. Because the look_down criteria will
925 often simply be:
926
927 id => 'fixme'
928
929 to find things like:
930
931 <a id=fixme href=http://www.somesite.org>replace_content</a>
932
933 You can call this method to shorten your typing a bit. You can simply
934 type
935
936 $elem->content_handler( fixme => 'new text' )
937
938 Instead of typing:
939
940 $elem->set_child_content(sid => 'fixme', 'new text')
941
942 ALSO NOTE: you can pass a hash whose keys are C<id>s and whose values
943 are the content you want there and it will perform the replacement on
944 each hash member:
945
946 my %id_content = (name => "Terrence Brannon",
947 email => 'tbrannon@in.com',
948 balance => 666,
949 content => $main_content);
950 $tree->content_handler(%id_content);
951
952 =head3 $tree->highlander($subtree_span_id, $conditionals, @conditionals_args)
953
954 This allows for "if-then-else" style processing. Highlander was a
955 movie in which only one would survive. Well, in terms of a tree when
956 looking at a structure that you want to process in C<if-then-else>
957 style, only one child will survive. For example, given this HTML
958 template:
959
960 <span klass="highlander" id="age_dialog">
961 <span id="under10">
962 Hello, does your mother know you're
963 using her AOL account?
964 </span>
965 <span id="under18">
966 Sorry, you're not old enough to enter
967 (and too dumb to lie about your age)
968 </span>
969 <span id="welcome">
970 Welcome
971 </span>
972 </span>
973
974 We only want one child of the C<span> tag with id C<age_dialog> to
975 remain based on the age of the person visiting the page.
976
977 So, let's setup a call that will prune the subtree as a function of
978 age:
979
980 sub process_page {
981 my $age = shift;
982 my $tree = HTML::TreeBuilder->new_from_file('t/html/highlander.html');
983
984 $tree->highlander
985 (age_dialog =>
986 [
987 under10 => sub { $_[0] < 10},
988 under18 => sub { $_[0] < 18},
989 welcome => sub { 1 }
990 ],
991 $age
992 );
993
994 And there we have it. If the age is less than 10, then the node with
995 id C<under10> remains. For age less than 18, the node with id
996 C<under18> remains. Otherwise our "else" condition fires and the child
997 with id C<welcome> remains.
998
999 =head3 $tree->passover(@id_of_element)
1000
1001 In some cases, you know exactly which element(s) should survive. In
1002 this case, you can simply call C<passover> to remove it's (their)
1003 siblings. For the HTML above, you could delete C<under10> and
1004 C<welcome> by simply calling:
1005
1006 $tree->passover('under18');
1007
1008 Because passover takes an array, you can specify several children to
1009 preserve.
1010
1011 =head3 $tree->highlander2($tree, $conditionals, @conditionals_args)
1012
1013 Right around the same time that C<table2()> came into being,
1014 Seamstress began to tackle tougher and tougher processing problems. It
1015 became clear that a more powerful highlander was needed... one that
1016 not only snipped the tree of the nodes that should not survive, but
1017 one that allows for post-processing of the survivor node. And one that
1018 was more flexible with how to find the nodes to snip.
1019
1020 Thus (drum roll) C<highlander2()>.
1021
1022 So let's look at our HTML which requires post-selection processing:
1023
1024 <span klass="highlander" id="age_dialog">
1025 <span id="under10">
1026 Hello, little <span id=age>AGE</span>-year old,
1027 does your mother know you're using her AOL account?
1028 </span>
1029 <span id="under18">
1030 Sorry, you're only <span id=age>AGE</span>
1031 (and too dumb to lie about your age)
1032 </span>
1033 <span id="welcome">
1034 Welcome, isn't it good to be <span id=age>AGE</span> years old?
1035 </span>
1036 </span>
1037
1038 In this case, a branch survives, but it has dummy data in it. We must
1039 take the surviving segment of HTML and rewrite the age C<span> with
1040 the age. Here is how we use C<highlander2()> to do so:
1041
1042 sub replace_age {
1043 my $branch = shift;
1044 my $age = shift;
1045 $branch->look_down(id => 'age')->replace_content($age);
1046 }
1047
1048 my $if_then = $tree->look_down(id => 'age_dialog');
1049
1050 $if_then->highlander2(
1051 cond => [
1052 under10 => [
1053 sub { $_[0] < 10} ,
1054 \&replace_age
1055 ],
1056 under18 => [
1057 sub { $_[0] < 18} ,
1058 \&replace_age
1059 ],
1060 welcome => [
1061 sub { 1 },
1062 \&replace_age
1063 ]
1064 ],
1065 cond_arg => [ $age ]
1066 );
1067
1068 We pass it the tree (C<$if_then>), an arrayref of conditions (C<cond>)
1069 and an arrayref of arguments which are passed to the C<cond>s and to
1070 the replacement subs.
1071
1072 The C<under10>, C<under18> and C<welcome> are id attributes in the
1073 tree of the siblings of which only one will survive. However, should
1074 you need to do more complex look-downs to find the survivor, then
1075 supply an array ref instead of a simple scalar:
1076
1077 $if_then->highlander2(
1078 cond => [
1079 [class => 'r12'] => [
1080 sub { $_[0] < 10} ,
1081 \&replace_age
1082 ],
1083 [class => 'z22'] => [
1084 sub { $_[0] < 18} ,
1085 \&replace_age
1086 ],
1087 [class => 'w88'] => [
1088 sub { 1 },
1089 \&replace_age
1090 ]
1091 ],
1092 cond_arg => [ $age ]
1093 );
1094
1095 =head3 $tree->overwrite_attr($mutation_attr => $mutating_closures)
1096
1097 This method is designed for taking a tree and reworking a set of nodes
1098 in a stereotyped fashion. For instance let's say you have 3 remote
1099 image archives, but you don't want to put long URLs in your img src
1100 tags for reasons of abstraction, re-use and brevity. So instead you do
1101 this:
1102
1103 <img src="/img/smiley-face.jpg" fixup="src lnc">
1104 <img src="/img/hot-babe.jpg" fixup="src playboy">
1105 <img src="/img/footer.jpg" fixup="src foobar">
1106
1107 and then when the tree of HTML is being processed, you make this call:
1108
1109 my %closures = (
1110 lnc => sub { my ($tree, $mute_node, $attr_value)= @_; "http://lnc.usc.edu$attr_value" },
1111 playboy => sub { my ($tree, $mute_node, $attr_value)= @_; "http://playboy.com$attr_value" }
1112 foobar => sub { my ($tree, $mute_node, $attr_value)= @_; "http://foobar.info$attr_value" }
1113 )
1114
1115 $tree->overwrite_attr(fixup => \%closures) ;
1116
1117 and the tags come out modified like so:
1118
1119 <img src="http://lnc.usc.edu/img/smiley-face.jpg" fixup="src lnc">
1120 <img src="http://playboy.com/img/hot-babe.jpg" fixup="src playboy">
1121 <img src="http://foobar.info/img/footer.jpg" fixup="src foobar">
1122
1123 =head3 $tree->mute_elem($mutation_attr => $mutating_closures, [ $post_hook ] )
1124
1125 This is a generalization of C<overwrite_attr>. C<overwrite_attr>
1126 assumes the return value of the closure is supposed overwrite an
1127 attribute value and does it for you. C<mute_elem> is a more general
1128 function which does nothing but hand the closure the element and let
1129 it mutate it as it jolly well pleases :)
1130
1131 In fact, here is the implementation of C<overwrite_attr> to give you a
1132 taste of how C<mute_attr> is used:
1133
1134 sub overwrite_action {
1135 my ($mute_node, %X) = @_;
1136
1137 $mute_node->attr($X{local_attr}{name} => $X{local_attr}{value}{new});
1138 }
1139
1140
1141 sub HTML::Element::overwrite_attr {
1142 my $tree = shift;
1143
1144 $tree->mute_elem(@_, \&overwrite_action);
1145 }
1146
1147 =head2 Tree-Building Methods
1148
1149 =head3 Unrolling an array via a single sample element (<ul> container)
1150
1151 This is best described by example. Given this HTML:
1152
1153 <strong>Here are the things I need from the store:</strong>
1154 <ul>
1155 <li class="store_items">Sample item</li>
1156 </ul>
1157
1158 We can unroll it like so:
1159
1160 my $li = $tree->look_down(class => 'store_items');
1161
1162 my @items = qw(bread butter vodka);
1163
1164 $tree->iter($li => @items);
1165
1166 To produce this:
1167
1168 <html>
1169 <head></head>
1170 <body>Here are the things I need from the store:
1171 <ul>
1172 <li class="store_items">bread</li>
1173 <li class="store_items">butter</li>
1174 <li class="store_items">vodka</li>
1175 </ul>
1176 </body>
1177 </html>
1178
1179 Now, you might be wondering why the API call is:
1180
1181 $tree->iter($li => @items)
1182
1183 instead of:
1184
1185 $li->iter(@items)
1186
1187 and there is no good answer. The latter would be more concise and it
1188 is what I should have done.
1189
1190 =head3 Unrolling an array via n sample elements (<dl> container)
1191
1192 C<iter()> was fine for awhile, but some things (e.g. definition lists)
1193 need a more general function to make them easy to do. Hence
1194 C<iter2()>. This function will be explained by example of unrolling a
1195 simple definition list.
1196
1197 So here's our mock-up HTML from the designer:
1198
1199 <dl class="dual_iter" id="service_plan">
1200 <dt>Artist</dt>
1201 <dd>A person who draws blood.</dd>
1202
1203 <dt>Musician</dt>
1204 <dd>A clone of Iggy Pop.</dd>
1205
1206 <dt>Poet</dt>
1207 <dd>A relative of Edgar Allan Poe.</dd>
1208
1209 <dt class="adstyle">sample header</dt>
1210 <dd class="adstyle2">sample data</dd>
1211 </dl>
1212
1213
1214 And we want to unroll our data set:
1215
1216 my @items = (
1217 ['the pros' => 'never have to worry about service again'],
1218 ['the cons' => 'upfront extra charge on purchase'],
1219 ['our choice' => 'go with the extended service plan']
1220 );
1221
1222
1223 Now, let's make this problem a bit harder to show off the power of
1224 C<iter2()>. Let's assume that we want only the last <dt> and it's
1225 accompanying <dd> (the one with "sample data") to be used as the
1226 sample data for unrolling with our data set. Let's further assume that
1227 we want them to remain in the final output.
1228
1229 So now, the API to C<iter2()> will be discussed and we will explain
1230 how our goal of getting our data into HTML fits into the API.
1231
1232 =over 4
1233
1234 =item * wrapper_ld
1235
1236 This is how to look down and find the container of all the elements we
1237 will be unrolling. The <dl> tag is the container for the dt and dd
1238 tags we will be unrolling.
1239
1240 If you pass an anonymous subroutine, then it is presumed that
1241 execution of this subroutine will return the HTML::Element
1242 representing the container tag. If you pass an array ref, then this
1243 will be dereferenced and passed to C<HTML::Element::look_down()>.
1244
1245 default value: C<< ['_tag' => 'dl'] >>
1246
1247 Based on the mock HTML above, this default is fine for finding our
1248 container tag. So let's move on.
1249
1250 =item * wrapper_data
1251
1252 This is an array reference of data that we will be putting into the
1253 container. You must supply this. C<@items> above is our
1254 C<wrapper_data>.
1255
1256 =item * wrapper_proc
1257
1258 After we find the container via C<wrapper_ld>, we may want to
1259 pre-process some aspect of this tree. In our case the first two sets
1260 of dt and dd need to be removed, leaving the last dt and dd. So, we
1261 supply a C<wrapper_proc> which will do this.
1262
1263 default: undef
1264
1265 =item * item_ld
1266
1267 This anonymous subroutine returns an array ref of C<HTML::Element>s
1268 that will be cloned and populated with item data (item data is a "row"
1269 of C<wrapper_data>).
1270
1271 default: returns an arrayref consisting of the dt and dd element
1272 inside the container.
1273
1274 =item * item_data
1275
1276 This is a subroutine that takes C<wrapper_data> and retrieves one
1277 "row" to be "pasted" into the array ref of C<HTML::Element>s found via
1278 C<item_ld>. I hope that makes sense.
1279
1280 default: shifts C<wrapper_data>.
1281
1282 =item * item_proc
1283
1284 This is a subroutine that takes the C<item_data> and the
1285 C<HTML::Element>s found via C<item_ld> and produces an arrayref of
1286 C<HTML::Element>s which will eventually be spliced into the container.
1287
1288 Note that this subroutine MUST return the new items. This is done So
1289 that more items than were passed in can be returned. This is useful
1290 when, for example, you must return 2 dts for an input data item. And
1291 when would you do this? When a single term has multiple spellings for
1292 instance.
1293
1294 default: expects C<item_data> to be an arrayref of two elements and
1295 C<item_elems> to be an arrayref of two C<HTML::Element>s. It replaces
1296 the content of the C<HTML::Element>s with the C<item_data>.
1297
1298 =item * splice
1299
1300 After building up an array of C<@item_elems>, the subroutine passed as
1301 C<splice> will be given the parent container HTML::Element and the
1302 C<@item_elems>. How the C<@item_elems> end up in the container is up
1303 to this routine: it could put half of them in. It could unshift them
1304 or whatever.
1305
1306 default: C<< $container->splice_content(0, 2, @item_elems) >> In other
1307 words, kill the 2 sample elements with the newly generated @item_elems
1308
1309 =back
1310
1311 So now that we have documented the API, let's see the call we need:
1312
1313 $tree->iter2(
1314 # default wrapper_ld ok.
1315 wrapper_data => \@items,
1316 wrapper_proc => sub {
1317 my ($container) = @_;
1318
1319 # only keep the last 2 dts and dds
1320 my @content_list = $container->content_list;
1321 $container->splice_content(0, @content_list - 2);
1322 },
1323
1324 # default item_ld is fine.
1325 # default item_data is fine.
1326 # default item_proc is fine.
1327 splice => sub {
1328 my ($container, @item_elems) = @_;
1329 $container->unshift_content(@item_elems);
1330 },
1331 debug => 1,
1332 );
1333
1334 =head3 Select Unrolling
1335
1336 The C<unroll_select> method has this API:
1337
1338 $tree->unroll_select(
1339 select_label => $id_label,
1340 option_value => $closure, # how to get option value from data row
1341 option_content => $closure, # how to get option content from data row
1342 option_selected => $closure, # boolean to decide if SELECTED
1343 data => $data # the data to be put into the SELECT
1344 data_iter => $closure # the thing that will get a row of data
1345 debug => $boolean,
1346 append => $boolean, # remove the sample <OPTION> data or append?
1347 );
1348
1349 Here's an example:
1350
1351 $tree->unroll_select(
1352 select_label => 'clan_list',
1353 option_value => sub { my $row = shift; $row->clan_id },
1354 option_content => sub { my $row = shift; $row->clan_name },
1355 option_selected => sub { my $row = shift; $row->selected },
1356 data => \@query_results,
1357 data_iter => sub { my $data = shift; $data->next },
1358 append => 0,
1359 debug => 0
1360 );
1361
1362 =head2 Tree-Building Methods: Table Generation
1363
1364 Matthew Sisk has a much more intuitive (imperative) way to generate
1365 tables via his module L<HTML::ElementTable|HTML::ElementTable>.
1366
1367 However, for those with callback fever, the following method is
1368 available. First, we look at a nuts and bolts way to build a table
1369 using only standard L<HTML::Tree> API calls. Then the C<table> method
1370 available here is discussed.
1371
1372 =head3 Sample Model
1373
1374 package Simple::Class;
1375
1376 use Set::Array;
1377
1378 my @name = qw(bob bill brian babette bobo bix);
1379 my @age = qw(99 12 44 52 12 43);
1380 my @weight = qw(99 52 80 124 120 230);
1381
1382
1383 sub new {
1384 my $this = shift;
1385 bless {}, ref($this) || $this;
1386 }
1387
1388 sub load_data {
1389 my @data;
1390
1391 for (0 .. 5) {
1392 push @data, {
1393 age => $age[rand $#age] + int rand 20,
1394 name => shift @name,
1395 weight => $weight[rand $#weight] + int rand 40
1396 }
1397 }
1398
1399 Set::Array->new(@data);
1400 }
1401
1402 1;
1403
1404 =head4 Sample Usage:
1405
1406 my $data = Simple::Class->load_data;
1407 ++$_->{age} for @$data
1408
1409 =head3 Inline Code to Unroll a Table
1410
1411 =head4 HTML
1412
1413 <html>
1414 <table id="load_data">
1415 <tr> <th>name</th><th>age</th><th>weight</th> </tr>
1416 <tr id="iterate">
1417 <td id="name"> NATURE BOY RIC FLAIR </td>
1418 <td id="age"> 35 </td>
1419 <td id="weight"> 220 </td>
1420 </tr>
1421 </table>
1422 </html>
1423
1424
1425 =head4 The manual way (*NOT* recommended)
1426
1427 require 'simple-class.pl';
1428 use HTML::Seamstress;
1429
1430 # load the view
1431 my $seamstress = HTML::Seamstress->new_from_file('simple.html');
1432
1433 # load the model
1434 my $o = Simple::Class->new;
1435 my $data = $o->load_data;
1436
1437 # find the <table> and <tr>
1438 my $table_node = $seamstress->look_down('id', 'load_data');
1439 my $iter_node = $table_node->look_down('id', 'iterate');
1440 my $table_parent = $table_node->parent;
1441
1442
1443 # drop the sample <table> and <tr> from the HTML
1444 # only add them in if there is data in the model
1445 # this is achieved via the $add_table flag
1446
1447 $table_node->detach;
1448 $iter_node->detach;
1449 my $add_table;
1450
1451 # Get a row of model data
1452 while (my $row = shift @$data) {
1453
1454 # We got row data. Set the flag indicating ok to hook the table into the HTML
1455 ++$add_table;
1456
1457 # clone the sample <tr>
1458 my $new_iter_node = $iter_node->clone;
1459
1460 # find the tags labeled name age and weight and
1461 # set their content to the row data
1462 $new_iter_node->content_handler($_ => $row->{$_})
1463 for qw(name age weight);
1464
1465 $table_node->push_content($new_iter_node);
1466
1467 }
1468
1469 # reattach the table to the HTML tree if we loaded data into some table rows
1470
1471 $table_parent->push_content($table_node) if $add_table;
1472
1473 print $seamstress->as_HTML;
1474
1475 =head3 $tree->table() : API call to Unroll a Table
1476
1477 require 'simple-class.pl';
1478 use HTML::Seamstress;
1479
1480 # load the view
1481 my $seamstress = HTML::Seamstress->new_from_file('simple.html');
1482 # load the model
1483 my $o = Simple::Class->new;
1484
1485 $seamstress->table
1486 (
1487 # tell seamstress where to find the table, via the method call
1488 # ->look_down('id', $gi_table). Seamstress detaches the table from the
1489 # HTML tree automatically if no table rows can be built
1490
1491 gi_table => 'load_data',
1492
1493 # tell seamstress where to find the tr. This is a bit useless as
1494 # the <tr> usually can be found as the first child of the parent
1495
1496 gi_tr => 'iterate',
1497
1498 # the model data to be pushed into the table
1499
1500 table_data => $o->load_data,
1501
1502 # the way to take the model data and obtain one row
1503 # if the table data were a hashref, we would do:
1504 # my $key = (keys %$data)[0]; my $val = $data->{$key}; delete $data->{$key}
1505
1506 tr_data => sub {
1507 my ($self, $data) = @_;
1508 shift @{$data} ;
1509 },
1510
1511 # the way to take a row of data and fill the <td> tags
1512
1513 td_data => sub {
1514 my ($tr_node, $tr_data) = @_;
1515 $tr_node->content_handler($_ => $tr_data->{$_})
1516 for qw(name age weight)
1517 }
1518 );
1519
1520 print $seamstress->as_HTML;
1521
1522 =head4 Looping over Multiple Sample Rows
1523
1524 * HTML
1525
1526 <html>
1527 <table id="load_data" CELLPADDING=8 BORDER=2>
1528 <tr> <th>name</th><th>age</th><th>weight</th> </tr>
1529 <tr id="iterate1" BGCOLOR="white" >
1530 <td id="name"> NATURE BOY RIC FLAIR </td>
1531 <td id="age"> 35 </td>
1532 <td id="weight"> 220 </td>
1533 </tr>
1534 <tr id="iterate2" BGCOLOR="#CCCC99">
1535 <td id="name"> NATURE BOY RIC FLAIR </td>
1536 <td id="age"> 35 </td>
1537 <td id="weight"> 220 </td>
1538 </tr>
1539 </table>
1540 </html>
1541
1542 * Only one change to last API call.
1543
1544 This:
1545
1546 gi_tr => 'iterate',
1547
1548 becomes this:
1549
1550 gi_tr => ['iterate1', 'iterate2']
1551
1552 =head3 $tree->table2() : New API Call to Unroll a Table
1553
1554 After 2 or 3 years with C<table()>, I began to develop production
1555 websites with it and decided it needed a cleaner interface,
1556 particularly in the area of handling the fact that C<id> tags will be
1557 the same after cloning a table row.
1558
1559 First, I will give a dry listing of the function's argument
1560 parameters. This will not be educational most likely. A better way to
1561 understand how to use the function is to read through the incremental
1562 unrolling of the function's interface given in conversational style
1563 after the dry listing. But take your pick. It's the same information
1564 given in two different ways.
1565
1566 =head4 Dry/technical parameter documentation
1567
1568 C<< $tree->table2(%param) >> takes the following arguments:
1569
1570 =over
1571
1572 =item * C<< table_ld => $look_down >> : optional
1573
1574 How to find the C<table> element in C<$tree>. If C<$look_down> is an
1575 arrayref, then use C<look_down>. If it is a CODE ref, then call it,
1576 passing it C<$tree>.
1577
1578 Defaults to C<< ['_tag' => 'table'] >> if not passed in.
1579
1580 =item * C<< table_data => $tabular_data >> : required
1581
1582 The data to fill the table with. I<Must> be passed in.
1583
1584 =item * C<< table_proc => $code_ref >> : not implemented
1585
1586 A subroutine to do something to the table once it is found. Not
1587 currently implemented. Not obviously necessary. Just created because
1588 there is a C<tr_proc> and C<td_proc>.
1589
1590 =item * C<< tr_ld => $look_down >> : optional
1591
1592 Same as C<table_ld> but for finding the table row elements. Please
1593 note that the C<tr_ld> is done on the table node that was found
1594 I<instead> of the whole HTML tree. This makes sense. The C<tr>s that
1595 you want exist below the table that was just found.
1596
1597 Defaults to C<< ['_tag' => 'tr'] >> if not passed in.
1598
1599 =item * C<< tr_data => $code_ref >> : optional
1600
1601 How to take the C<table_data> and return a row. Defaults to:
1602
1603 sub { my ($self, $data) = @_;
1604 shift(@{$data}) ;
1605 }
1606
1607 =item * C<< tr_proc => $code_ref >> : optional
1608
1609 Something to do to the table row we are about to add to the table we
1610 are making. Defaults to a routine which makes the C<id> attribute
1611 unique:
1612
1613 sub {
1614 my ($self, $tr, $tr_data, $tr_base_id, $row_count) = @_;
1615 $tr->attr(id => sprintf "%s_%d", $tr_base_id, $row_count);
1616 }
1617
1618 =item * C<< td_proc => $code_ref >> : required
1619
1620 This coderef will take the row of data and operate on the C<td> cells
1621 that are children of the C<tr>. See C<t/table2.t> for several usage
1622 examples.
1623
1624 Here's a sample one:
1625
1626 sub {
1627 my ($tr, $data) = @_;
1628 my @td = $tr->look_down('_tag' => 'td');
1629 for my $i (0..$#td) {
1630 $td[$i]->splice_content(0, 1, $data->[$i]);
1631 }
1632 }
1633
1634 =back
1635
1636 =head4 Conversational parameter documentation
1637
1638 The first thing you need is a table. So we need a look down for that.
1639 If you don't give one, it defaults to
1640
1641 ['_tag' => 'table']
1642
1643 What good is a table to display in without data to display?! So you
1644 must supply a scalar representing your tabular data source. This
1645 scalar might be an array reference, a C<next>able iterator, a DBI
1646 statement handle. Whatever it is, it can be iterated through to build
1647 up rows of table data. These two required fields (the way to find the
1648 table and the data to display in the table) are C<table_ld> and
1649 C<table_data> respectively. A little more on C<table_ld>. If this
1650 happens to be a CODE ref, then execution of the code ref is presumed
1651 to return the C<HTML::Element> representing the table in the HTML
1652 tree.
1653
1654 Next, we get the row or rows which serve as sample C<tr> elements by
1655 doing a C<look_down> from the C<table_elem>. While normally one sample
1656 row is enough to unroll a table, consider when you have alternating
1657 table rows. This API call would need one of each row so that it can
1658 cycle through the sample rows as it loops through the data.
1659 Alternatively, you could always just use one row and make the
1660 necessary changes to the single C<tr> row by mutating the element in
1661 C<tr_proc>, discussed below. The default C<tr_ld> is C<< ['_tag' =>
1662 'tr'] >> but you can overwrite it. Note well, if you overwrite it with
1663 a subroutine, then it is expected that the subroutine will return the
1664 C<HTML::Element>(s) which are C<tr> element(s). The reason a
1665 subroutine might be preferred is in the case that the HTML designers
1666 gave you 8 sample C<tr> rows but only one prototype row is needed. So
1667 you can write a subroutine, to splice out the 7 rows you don't need
1668 and leave the one sample row remaining so that this API call can clone
1669 it and supply it to the C<tr_proc> and C<td_proc> calls.
1670
1671 Now, as we move through the table rows with table data, we need to do
1672 two different things on each table row:
1673
1674 =over 4
1675
1676 =item * get one row of data from the C<table_data> via C<tr_data>
1677
1678 The default procedure assumes the C<table_data> is an array reference
1679 and shifts a row off of it:
1680
1681 sub {
1682 my ($self, $data) = @_;
1683 shift @{$data};
1684 }
1685
1686 Your function MUST return undef when there is no more rows to lay out.
1687
1688 =item * take the C<tr> element and mutate it via C<tr_proc>
1689
1690 The default procedure simply makes the id of the table row unique:
1691
1692 sub {
1693 my ($self, $tr, $tr_data, $row_count, $root_id) = @_;
1694 $tr->attr(id => sprintf "%s_%d", $root_id, $row_count);
1695 }
1696
1697 =back
1698
1699 Now that we have our row of data, we call C<td_proc> so that it can
1700 take the data and the C<td> cells in this C<tr> and process them. This
1701 function I<must> be supplied.
1702
1703 =head3 Whither a Table with No Rows
1704
1705 Often when a table has no rows, we want to display a message
1706 indicating this to the view. Use conditional processing to decide what
1707 to display:
1708
1709 <span id=no_data>
1710 <table><tr><td>No Data is Good Data</td></tr></table>
1711 </span>
1712 <span id=load_data>
1713 <html>
1714 <table id="load_data">
1715 <tr> <th>name</th><th>age</th><th>weight</th> </tr>
1716 <tr id="iterate">
1717 <td id="name"> NATURE BOY RIC FLAIR </td>
1718 <td id="age"> 35 </td>
1719 <td id="weight"> 220 </td>
1720 </tr>
1721 </table>
1722 </html>
1723 </span>
1724
1725 =head2 Tree-Killing Methods
1726
1727 =head3 $tree->prune
1728
1729 This removes any nodes from the tree which consist of nothing or
1730 nothing but whitespace. See also delete_ignorable_whitespace in
1731 L<HTML::Element>.
1732
1733 =head2 Loltree Functions
1734
1735 A loltree is an arrayref consisting of arrayrefs which is used by C<<
1736 new_from__lol >> in L<HTML::Element> to produce HTML trees. The CPAN
1737 distro L<XML::Element::Tolol> creates such XML trees by parsing XML
1738 files, analagous to L<XML::Toolkit>. The purpose of the functions in
1739 this section is to allow you manipulate a loltree programmatically.
1740
1741 These could not be methods because if you bless a loltree, then
1742 HTML::Tree will barf.
1743
1744 =head3 HTML::Element::newchild($lol, $parent_label, @newchild)
1745
1746 Given this initial loltree:
1747
1748 my $initial_lol = [ note => [ shopping => [ item => 'sample' ] ] ];
1749
1750 This code:
1751
1752 sub shopping_items {
1753 my @shopping_items = map { [ item => _ ] } qw(bread butter beans);
1754 @shopping_items;
1755 }
1756
1757 my $new_lol = HTML::Element::newnode($initial_lol, item => shopping_items());
1758
1759 will replace the single sample with a list of shopping items:
1760
1761 [
1762 'note',
1763 [
1764 'shopping',
1765 [
1766 'item',
1767 'bread'
1768 ],
1769 [
1770 'item',
1771 'butter'
1772 ],
1773 [
1774 'item',
1775 'beans'
1776 ]
1777
1778 ]
1779 ];
1780
1781 Thanks to kcott and the other Perlmonks in this thread:
1782 http://www.perlmonks.org/?node_id=912416
1783
1784
1785 =head1 SEE ALSO
1786
1787 =head2 L<HTML::Tree>
1788
1789 A perl package for creating and manipulating HTML trees.
1790
1791 =head2 L<HTML::ElementTable>
1792
1793 An L<HTML::Tree> - based module which allows for manipulation of HTML
1794 trees using cartesian coordinations.
1795
1796 =head2 L<HTML::Seamstress>
1797
1798 An L<HTML::Tree> - based module inspired by XMLC
1799 (L<http://xmlc.enhydra.org>), allowing for dynamic HTML generation via
1800 tree rewriting.
1801
1802 =head2 Push-style templating systems
1803
1804 A comprehensive cross-language
1805 L<list of push-style templating systems|http://perlmonks.org/?node_id=674225>.
1806
1807 =head1 TODO
1808
1809 =over
1810
1811 =item * highlander2
1812
1813 currently the API expects the subtrees to survive or be pruned to be
1814 identified by id:
1815
1816 $if_then->highlander2([
1817 under10 => sub { $_[0] < 10} ,
1818 under18 => sub { $_[0] < 18} ,
1819 welcome => [
1820 sub { 1 },
1821 sub {
1822 my $branch = shift;
1823 $branch->look_down(id => 'age')->replace_content($age);
1824 }
1825 ]
1826 ], $age);
1827
1828 but, it should be more flexible. the C<under10>, and C<under18> are
1829 expected to be ids in the tree... but it is not hard to have a check
1830 to see if this field is an array reference and if it, then to do a
1831 look down instead:
1832
1833 $if_then->highlander2([
1834 [class => 'under10'] => sub { $_[0] < 10} ,
1835 [class => 'under18'] => sub { $_[0] < 18} ,
1836 [class => 'welcome'] => [
1837 sub { 1 },
1838 sub {
1839 my $branch = shift;
1840 $branch->look_down(id => 'age')->replace_content($age);
1841 }
1842 ]
1843 ], $age);
1844
1845 =back
1846
1847 =head1 AUTHOR
1848
1849 Original author Terrence Brannon, E<lt>tbone@cpan.orgE<gt>.
1850
1851 Adopted by Marius Gavrilescu C<< <marius@ieval.ro> >>.
1852
1853 I appreciate the feedback from M. David Moussa Leo Keita regarding
1854 some issues with the test suite, namely (1) CRLF leading to test
1855 breakage in F<t/crunch.t> and (2) using the wrong module in
1856 F<t/prune.t> thus not having the right functionality available.
1857
1858 Many thanks to BARBIE for his RT bug report.
1859
1860 Many thanks to perlmonk kcott for his work on array rewriting:
1861 L<http://www.perlmonks.org/?node_id=912416>. It was crucial in the
1862 development of newchild.
1863
1864 =head1 COPYRIGHT AND LICENSE
1865
1866 Coypright (C) 2014-2015 by Marius Gavrilescu
1867
1868 Copyright (C) 2004-2012 by Terrence Brannon
1869
1870 This library is free software; you can redistribute it and/or modify
1871 it under the same terms as Perl itself, either Perl version 5.8.4 or,
1872 at your option, any later version of Perl 5 you may have available.
1873
1874
1875 =cut
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