1 package HTML
::Element
::Library
;
11 use Array
::Group
qw(:all);
15 use List
::MoreUtils qw
/:all/;
16 use Params
::Validate
qw(:all);
19 use List
::Rotation
::Cycle
;
21 our %EXPORT_TAGS = ( 'all' => [ qw() ] );
22 our @EXPORT_OK = ( @
{ $EXPORT_TAGS{'all'} } );
27 our $VERSION = '3.53';
30 # Preloaded methods go here.
32 sub HTML
::Element
::siblings
{
34 my $p = $element->parent;
39 sub HTML
::Element
::passover
{
40 my ($tree, $child_id) = @_;
42 #warn "ARGS: my ($tree, $child)";
44 my $exodus = $tree->look_down(id
=> $child_id);
46 my @s = HTML
::Element
::siblings
($exodus);
48 warn "sibling count", scalar @s;
49 warn "siblings", join ':', @s;
53 warn "ref sib", ref $s;
55 if ($s->attr('id') eq $child_id) {
62 return $exodus; # Goodbye Egypt! http://en.wikipedia.org/wiki/Passover
66 sub HTML
::Element
::sibdex
{
69 firstidx
{ $_ eq $element } $element->siblings
73 sub HTML
::Element
::addr
{ goto &HTML
::Element
::sibdex
}
75 sub HTML
::Element
::replace_content
{
77 $elem->delete_content;
78 $elem->push_content(@_);
81 sub HTML
::Element
::wrap_content
{
82 my($self, $wrap) = @_;
83 my $content = $self->content;
85 $wrap->push_content(@
$content);
89 $self->push_content($wrap);
94 sub HTML
::Element
::Library
::super_literal
{
97 HTML
::Element
->new('~literal', text
=> $text);
101 sub HTML
::Element
::position
{
102 # Report coordinates by chasing addr's up the
103 # HTML::ElementSuper tree. We know we've reached
104 # the top when a) there is no parent, or b) the
105 # parent is some HTML::Element unable to report
111 unshift(@pos, $a) if defined $a;
118 sub HTML
::Element
::content_handler
{
119 my ($tree, $id_name, $content) = @_;
121 $tree->set_child_content(id
=> $id_name, $content);
134 sub HTML
::Element
::iter
{
135 my ($tree, $p, @data) = @_;
137 # warn 'P: ' , $p->attr('id') ;
138 # warn 'H: ' , $p->as_HTML;
140 # my $id_incr = make_counter;
142 my $new_item = clone
$p;
143 $new_item->replace_content($_);
144 # $new_item->attr('id', $id_incr->( $p->attr('id') ));
148 $p->replace_with(@item);
153 sub HTML
::Element
::iter2
{
157 #warn "INPUT TO TABLE2: ", Dumper \@_;
161 wrapper_ld
=> { default => ['_tag' => 'dl'] },
163 wrapper_proc
=> { default => undef },
164 item_ld
=> { default => sub {
167 $tree->look_down('_tag' => 'dt'),
168 $tree->look_down('_tag' => 'dd')
172 item_data
=> { default => sub { my ($wrapper_data) = @_;
173 shift(@
{$wrapper_data}) ;
177 my ($item_elems, $item_data, $row_count) = @_;
178 $item_elems->[$_]->replace_content($item_data->[$_]) for (0,1) ;
181 splice => { default => sub {
182 my ($container, @item_elems) = @_;
183 $container->splice_content(0, 2, @item_elems);
186 debug
=> {default => 0}
190 warn "wrapper_data: " . Dumper
$p{wrapper_data
} if $p{debug
} ;
192 my $container = ref_or_ld
($tree, $p{wrapper_ld
});
193 warn "wrapper_(preproc): " . $container->as_HTML if $p{debug
} ;
194 $p{wrapper_proc
}->($container) if defined $p{wrapper_proc
} ;
195 warn "wrapper_(postproc): " . $container->as_HTML if $p{debug
} ;
197 my $_item_elems = $p{item_ld
}->($container);
204 my $item_data = $p{item_data
}->($p{wrapper_data
});
205 last unless defined $item_data;
207 warn Dumper
("item_data", $item_data);
210 my $item_elems = [ map { $_->clone } @
{$_item_elems} ] ;
213 for (@
{$item_elems}) {
214 warn "ITEM_ELEMS ", $_->as_HTML;
218 my $new_item_elems = $p{item_proc
}->($item_elems, $item_data, ++$row_count);
221 for (@
{$new_item_elems}) {
222 warn "NEWITEM_ELEMS ", $_->as_HTML;
227 push @item_elem, @
{$new_item_elems} ;
232 warn "pushing " . @item_elem . " elems " if $p{debug
} ;
234 $p{splice}->($container, @item_elem);
238 sub HTML
::Element
::dual_iter
{
239 my ($parent, $data) = @_;
241 my ($prototype_a, $prototype_b) = $parent->content_list;
243 # my $id_incr = make_counter;
248 confess
'dataset does not contain an even number of members';
250 my @iterable_data = ngroup
2 => @
$data;
253 my ($new_a, $new_b) = map { clone
$_ } ($prototype_a, $prototype_b) ;
254 $new_a->splice_content(0,1, $_->[0]);
255 $new_b->splice_content(0,1, $_->[1]);
256 #$_->attr('id', $id_incr->($_->attr('id'))) for ($new_a, $new_b) ;
260 $parent->splice_content(0, 2, @item);
265 sub HTML
::Element
::set_child_content
{
270 my $content_tag = $tree->look_down(@look_down);
272 unless ($content_tag) {
273 warn "criteria [@look_down] not found";
277 $content_tag->replace_content($content);
281 sub HTML
::Element
::highlander
{
282 my ($tree, $local_root_id, $aref, @arg) = @_;
284 ref $aref eq 'ARRAY' or confess
285 "must supply array reference";
288 @aref % 2 == 0 or confess
289 "supplied array ref must have an even number of entries";
291 warn __PACKAGE__
if $DEBUG;
294 while (my ($id, $test) = splice @aref, 0, 2) {
303 my @id_survivor = (id
=> $survivor);
304 my $survivor_node = $tree->look_down(@id_survivor);
306 # warn $local_root_id;
309 warn "survivor: $survivor" if $DEBUG;
310 warn "tree: " . $tree->as_HTML if $DEBUG;
312 $survivor_node or die "search for @id_survivor failed in tree($tree): " . $tree->as_HTML;
314 my $survivor_node_parent = $survivor_node->parent;
315 $survivor_node = $survivor_node->clone;
316 $survivor_node_parent->replace_content($survivor_node);
318 warn "new tree: " . $tree->as_HTML if $DEBUG;
324 sub HTML
::Element
::highlander2
{
327 my %p = validate
(@_, {
328 cond
=> { type
=> ARRAYREF
},
329 cond_arg
=> { type
=> ARRAYREF
,
332 debug
=> { default => 0 }
337 my @cond = @
{$p{cond
}};
338 @cond % 2 == 0 or confess
339 "supplied array ref must have an even number of entries";
341 warn __PACKAGE__
if $p{debug
};
343 my @cond_arg = @
{$p{cond_arg
}};
345 my $survivor; my $then;
346 while (my ($id, $if_then) = splice @cond, 0, 2) {
348 warn $id if $p{debug
};
351 if (ref $if_then eq 'ARRAY') {
352 ($if, $_then) = @
$if_then;
354 ($if, $_then) = ($if_then, sub {});
357 if ($if->(@cond_arg)) {
365 my @ld = (ref $survivor eq 'ARRAY')
370 warn "survivor: ", $survivor if $p{debug
};
371 warn "survivor_ld: ", Dumper \
@ld if $p{debug
};
374 my $survivor_node = $tree->look_down(@ld);
376 $survivor_node or confess
377 "search for @ld failed in tree($tree): " . $tree->as_HTML;
379 my $survivor_node_parent = $survivor_node->parent;
380 $survivor_node = $survivor_node->clone;
381 $survivor_node_parent->replace_content($survivor_node);
384 # **************** NEW FUNCTIONALITY *******************
386 # apply transforms on survivor node
389 warn "SURV::pre_trans " . $survivor_node->as_HTML if $p{debug
};
390 $then->($survivor_node, @cond_arg);
391 warn "SURV::post_trans " . $survivor_node->as_HTML if $p{debug
};
393 # **************** NEW FUNCTIONALITY *******************
402 sub overwrite_action
{
403 my ($mute_node, %X) = @_;
405 $mute_node->attr($X{local_attr
}{name
} => $X{local_attr
}{value
}{new
});
409 sub HTML
::Element
::overwrite_attr
{
412 $tree->mute_elem(@_, \
&overwrite_action
);
417 sub HTML
::Element
::mute_elem
{
418 my ($tree, $mute_attr, $closures, $post_hook) = @_;
420 warn "my mute_node = $tree->look_down($mute_attr => qr/.*/) ;";
421 my @mute_node = $tree->look_down($mute_attr => qr/.*/) ;
423 for my $mute_node (@mute_node) {
424 my ($local_attr,$mute_key) = split /\s+/, $mute_node->attr($mute_attr);
425 my $local_attr_value_current = $mute_node->attr($local_attr);
426 my $local_attr_value_new = $closures->{$mute_key}->($tree, $mute_node, $local_attr_value_current);
433 current
=> $local_attr_value_current,
434 new
=> $local_attr_value_new
443 sub HTML
::Element
::table
{
445 my ($s, %table) = @_;
449 # use Data::Dumper; warn Dumper \%table;
451 # ++$DEBUG if $table{debug} ;
454 # Get the table element
455 $table->{table_node
} = $s->look_down(id
=> $table{gi_table
});
456 $table->{table_node
} or confess
457 "table tag not found via (id => $table{gi_table}";
459 # Get the prototype tr element(s)
460 my @table_gi_tr = listify
$table{gi_tr
} ;
463 my $tr = $table->{table_node
}->look_down(id
=> $_);
464 $tr or confess
"tr with id => $_ not found";
468 warn "found " . @iter_node . " iter nodes " if $DEBUG;
469 # tie my $iter_node, 'Tie::Cycle', \@iter_node;
470 my $iter_node = List
::Rotation
::Cycle
->new(@iter_node);
473 warn Dumper
($iter_node, \
@iter_node) if $DEBUG;
475 # $table->{content} = $table{content};
476 #$table->{parent} = $table->{table_node}->parent;
479 # $table->{table_node}->detach;
480 # $_->detach for @iter_node;
485 my $row = $table{tr_data
}->($table, $table{table_data
});
486 last unless defined $row;
488 # get a sample table row and clone it.
489 my $I = $iter_node->next;
490 warn "I: $I" if $DEBUG;
491 my $new_iter_node = $I->clone;
494 $table{td_data
}->($new_iter_node, $row);
495 push @table_rows, $new_iter_node;
502 my $replace_with_elem = $s->look_down(id
=> shift @table_gi_tr) ;
504 $s->look_down(id
=> $_)->detach;
507 $replace_with_elem->replace_with(@table_rows);
515 my ($tree, $slot) = @_;
517 if (ref($slot) eq 'CODE') {
520 $tree->look_down(@
$slot);
526 sub HTML
::Element
::table2
{
534 table_ld
=> { default => ['_tag' => 'table'] },
536 table_proc
=> { default => undef },
538 tr_ld
=> { default => ['_tag' => 'tr'] },
539 tr_data
=> { default => sub { my ($self, $data) = @_;
542 tr_base_id
=> { default => undef },
543 tr_proc
=> { default => sub {} },
545 debug
=> {default => 0}
549 warn "INPUT TO TABLE2: ", Dumper \
@_ if $p{debug
};
551 warn "table_data: " . Dumper
$p{table_data
} if $p{debug
} ;
555 # use Data::Dumper; warn Dumper \%table;
557 # ++$DEBUG if $table{debug} ;
559 # Get the table element
561 $table->{table_node
} = ref_or_ld
( $tree, $p{table_ld
} ) ;
563 $table->{table_node
} or confess
564 "table tag not found via " . Dumper
($p{table_ld
}) ;
566 warn "table: " . $table->{table_node
}->as_HTML if $p{debug
};
569 # Get the prototype tr element(s)
570 my @proto_tr = ref_or_ld
( $table->{table_node
}, $p{tr_ld
} ) ;
572 warn "found " . @proto_tr . " iter nodes " if $p{debug
};
574 @proto_tr or return ;
577 warn $_->as_HTML for @proto_tr;
579 my $proto_tr = List
::Rotation
::Cycle
->new(@proto_tr);
581 my $tr_parent = $proto_tr[0]->parent;
582 warn "parent element of trs: " . $tr_parent->as_HTML if $p{debug
};
589 my $row = $p{tr_data
}->($table, $p{table_data
}, $row_count);
590 warn "data row: " . Dumper
$row if $p{debug
};
591 last unless defined $row;
593 # wont work: my $new_iter_node = $table->{iter_node}->clone;
594 my $new_tr_node = $proto_tr->next->clone;
595 warn "new_tr_node: $new_tr_node" if $p{debug
};
597 $p{tr_proc
}->($tree, $new_tr_node, $row, $p{tr_base_id
}, ++$row_count)
598 if defined $p{tr_proc
};
600 warn "data row redux: " . Dumper
$row if $p{debug
};
603 $p{td_proc
}->($new_tr_node, $row);
604 push @table_rows, $new_tr_node;
611 $_->detach for @proto_tr;
613 $tr_parent->push_content(@table_rows) if (@table_rows) ;
618 sub HTML
::Element
::unroll_select
{
620 my ($s, %select) = @_;
624 my $select_node = $s->look_down(id
=> $select{select_label
});
626 my $option = $select_node->look_down('_tag' => 'option');
633 while (my $row = $select{data_iter
}->($select{data
}))
636 my $o = $option->clone;
637 $o->attr('value', $select{option_value
}->($row));
638 $o->attr('SELECTED', 1) if ($select{option_selected
}->($row)) ;
640 $o->replace_content($select{option_content
}->($row));
641 $select_node->push_content($o);
649 sub HTML
::Element
::set_sibling_content
{
650 my ($elt, $content) = @_;
652 $elt->parent->splice_content($elt->pindex + 1, 1, $content);
656 sub HTML
::TreeBuilder
::parse_string
{
657 my ($package, $string) = @_;
659 my $h = HTML
::TreeBuilder
->new;
660 HTML
::TreeBuilder
->parse($string);
668 # Below is stub documentation for your module. You'd better edit it!
672 HTML::Element::Library - HTML::Element convenience functions
676 use HTML::Element::Library;
677 use HTML::TreeBuilder;
681 This method provides API calls for common actions on trees when using
686 The test suite contains examples of each of these methods in a
689 =head2 Positional Querying Methods
691 =head3 $elem->siblings
693 Return a list of all nodes under the same parent.
697 Return the index of C<$elem> into the array of siblings of which it is
698 a part. L<HTML::ElementSuper> calls this method C<addr> but I don't think
699 that is a descriptive name. And such naming is deceptively close to the
700 C<address> function of C<HTML::Element>. HOWEVER, in the interest of
701 backwards compatibility, both methods are available.
707 =head3 $elem->position()
709 Returns the coordinates of this element in the tree it inhabits.
710 This is accomplished by succesively calling addr() on ancestor
711 elements until either a) an element that does not support these
712 methods is found, or b) there are no more parents. The resulting
713 list is the n-dimensional coordinates of the element in the tree.
715 =head2 Element Decoration Methods
717 =head3 HTML::Element::Library::super_literal($text)
719 In L<HTML::Element>, Sean Burke discusses super-literals. They are
720 text which does not get escaped. Great for includng Javascript in
721 HTML. Also great for including foreign language into a document.
723 So, you basically toss C<super_literal> your text and back comes
724 your text wrapped in a C<~literal> element.
726 One of these days, I'll around to writing a nice C<EXPORT> section.
728 =head2 Tree Rewriting Methods
730 =head3 $elem->replace_content(@new_elem)
732 Replaces all of C<$elem>'s content with C<@new_elem>.
734 =head3 $elem->wrap_content($wrapper_element)
736 Wraps the existing content in the provided element. If the provided element
737 happens to be a non-element, a push_content is performed instead.
739 =head3 $elem->set_child_content(@look_down, $content)
741 This method looks down $tree using the criteria specified in @look_down using the the HTML::Element look_down() method.
743 After finding the node, it detaches the node's content and pushes $content as the node's content.
745 =head3 $tree->content_handler($sid_value , $content)
747 This is a convenience method. Because the look_down criteria will often simply be:
753 <a id=fixme href=http://www.somesite.org>replace_content</a>
755 You can call this method to shorten your typing a bit. You can simply type
757 $elem->content_handler( fixme => 'new text' )
761 $elem->set_child_content(sid => 'fixme', 'new text')
763 =head3 $tree->highlander($subtree_span_id, $conditionals, @conditionals_args)
765 This allows for "if-then-else" style processing. Highlander was a movie in
766 which only one would survive. Well, in terms of a tree when looking at a
767 structure that you want to process in C<if-then-else> style, only one child
768 will survive. For example, given this HTML template:
770 <span klass="highlander" id="age_dialog">
772 Hello, does your mother know you're
773 using her AOL account?
776 Sorry, you're not old enough to enter
777 (and too dumb to lie about your age)
784 We only want one child of the C<span> tag with id C<age_dialog> to remain
785 based on the age of the person visiting the page.
787 So, let's setup a call that will prune the subtree as a function of age:
791 my $tree = HTML::TreeBuilder->new_from_file('t/html/highlander.html');
796 under10 => sub { $_[0] < 10} ,
797 under18 => sub { $_[0] < 18} ,
803 And there we have it. If the age is less than 10, then the node with
804 id C<under10> remains. For age less than 18, the node with id C<under18>
806 Otherwise our "else" condition fires and the child with id C<welcome> remains.
808 =head3 $tree->highlander2($tree, $conditionals, @conditionals_args)
810 Right around the same time that C<table2()> came into being, Seamstress
811 began to tackle tougher and tougher processing problems. It became clear that
812 a more powerful highlander was needed... one that not only snipped the tree
813 of the nodes that should not survive, but one that allows for
814 post-processing of the survivor node. And one that was more flexible with
815 how to find the nodes to snip.
817 Thus (drum roll) C<highlander2()>.
819 So let's look at our HTML which requires post-selection processing:
821 <span klass="highlander" id="age_dialog">
823 Hello, little <span id=age>AGE</span>-year old,
824 does your mother know you're using her AOL account?
827 Sorry, you're only <span id=age>AGE</span>
828 (and too dumb to lie about your age)
831 Welcome, isn't it good to be <span id=age>AGE</span> years old?
835 In this case, a branch survives, but it has dummy data in it. We must take
836 the surviving segment of HTML and rewrite the age C<span> with the age.
837 Here is how we use C<highlander2()> to do so:
842 $branch->look_down(id => 'age')->replace_content($age);
845 my $if_then = $tree->look_down(id => 'age_dialog');
847 $if_then->highlander2(
865 We pass it the tree (C<$if_then>), an arrayref of conditions
866 (C<cond>) and an arrayref of arguments which are passed to the
867 C<cond>s and to the replacement subs.
869 The C<under10>, C<under18> and C<welcome> are id attributes in the
870 tree of the siblings of which only one will survive. However,
871 should you need to do
872 more complex look-downs to find the survivor,
873 then supply an array ref instead of a simple
877 $if_then->highlander2(
879 [class => 'r12'] => [
883 [class => 'z22'] => [
887 [class => 'w88'] => [
896 =head3 $tree->overwrite_attr($mutation_attr => $mutating_closures)
898 This method is designed for taking a tree and reworking a set of nodes in
899 a stereotyped fashion. For instance let's say you have 3 remote image
900 archives, but you don't want to put long URLs in your img src
901 tags for reasons of abstraction, re-use and brevity. So instead you do this:
903 <img src="/img/smiley-face.jpg" fixup="src lnc">
904 <img src="/img/hot-babe.jpg" fixup="src playboy">
905 <img src="/img/footer.jpg" fixup="src foobar">
907 and then when the tree of HTML is being processed, you make this call:
910 lnc => sub { my ($tree, $mute_node, $attr_value)= @_; "http://lnc.usc.edu$attr_value" },
911 playboy => sub { my ($tree, $mute_node, $attr_value)= @_; "http://playboy.com$attr_value" }
912 foobar => sub { my ($tree, $mute_node, $attr_value)= @_; "http://foobar.info$attr_value" }
915 $tree->overwrite_attr(fixup => \%closures) ;
917 and the tags come out modified like so:
919 <img src="http://lnc.usc.edu/img/smiley-face.jpg" fixup="src lnc">
920 <img src="http://playboy.com/img/hot-babe.jpg" fixup="src playboy">
921 <img src="http://foobar.info/img/footer.jpg" fixup="src foobar">
923 =head3 $tree->mute_elem($mutation_attr => $mutating_closures, [ $post_hook ] )
925 This is a generalization of C<overwrite_attr>. C<overwrite_attr>
926 assumes the return value of the
927 closure is supposed overwrite an attribute value and does it for you.
928 C<mute_elem> is a more general function which does nothing but
929 hand the closure the element and let it mutate it as it jolly well pleases :)
931 In fact, here is the implementation of C<overwrite_attr>
932 to give you a taste of how C<mute_attr> is used:
934 sub overwrite_action {
935 my ($mute_node, %X) = @_;
937 $mute_node->attr($X{local_attr}{name} => $X{local_attr}{value}{new});
941 sub HTML::Element::overwrite_attr {
944 $tree->mute_elem(@_, \&overwrite_action);
950 =head2 Tree-Building Methods: Unrolling an array via a single sample element (<ul> container)
952 This is best described by example. Given this HTML:
954 <strong>Here are the things I need from the store:</strong>
956 <li class="store_items">Sample item</li>
959 We can unroll it like so:
961 my $li = $tree->look_down(class => 'store_items');
963 my @items = qw(bread butter vodka);
965 $tree->iter($li => @items);
972 <body>Here are the things I need from the store:
974 <li class="store_items">bread</li>
975 <li class="store_items">butter</li>
976 <li class="store_items">vodka</li>
981 =head2 Tree-Building Methods: Unrolling an array via n sample elements (<dl> container)
983 C<iter()> was fine for awhile, but some things
984 (e.g. definition lists) need a more general function to make them easy to
985 do. Hence C<iter2()>. This function will be explained by example of unrolling
986 a simple definition list.
988 So here's our mock-up HTML from the designer:
990 <dl class="dual_iter" id="service_plan">
995 A person who draws blood.
1002 A clone of Iggy Pop.
1009 A relative of Edgar Allan Poe.
1012 <dt class="adstyle">sample header</dt>
1013 <dd class="adstyle2">sample data</dd>
1018 And we want to unroll our data set:
1021 ['the pros' => 'never have to worry about service again'],
1022 ['the cons' => 'upfront extra charge on purchase'],
1023 ['our choice' => 'go with the extended service plan']
1027 Now, let's make this problem a bit harder to show off the power of C<iter2()>.
1028 Let's assume that we want only the last <dt> and it's accompanying <dd>
1029 (the one with "sample data") to be used as the sample data
1030 for unrolling with our data set. Let's further assume that we want them to
1031 remain in the final output.
1033 So now, the API to C<iter2()> will be discussed and we will explain how our
1034 goal of getting our data into HTML fits into the API.
1040 This is how to look down and find the container of all the elements we will
1041 be unrolling. The <dl> tag is the container for the dt and dd tags we will be
1044 If you pass an anonymous subroutine, then it is presumed that execution of
1045 this subroutine will return the HTML::Element representing the container tag.
1046 If you pass an array ref, then this will be dereferenced and passed to
1047 C<HTML::Element::look_down()>.
1049 default value: C<< ['_tag' => 'dl'] >>
1051 Based on the mock HTML above, this default is fine for finding our container
1052 tag. So let's move on.
1054 =item * wrapper_data
1056 This is an array reference of data that we will be putting into the container.
1057 You must supply this. C<@items> above is our C<wrapper_data>.
1059 =item * wrapper_proc
1061 After we find the container via C<wrapper_ld>, we may want to pre-process
1062 some aspect of this tree. In our case the first two sets of dt and dd need
1063 to be removed, leaving the last dt and dd. So, we supply a C<wrapper_proc>
1070 This anonymous subroutine returns an array ref of C<HTML::Element>s that will
1071 be cloned and populated with item data
1072 (item data is a "row" of C<wrapper_data>).
1074 default: returns an arrayref consisting of the dt and dd element inside the
1079 This is a subroutine that takes C<wrapper_data> and retrieves one "row"
1080 to be "pasted" into the array ref of C<HTML::Element>s found via C<item_ld>.
1081 I hope that makes sense.
1083 default: shifts C<wrapper_data>.
1087 This is a subroutine that takes the C<item_data> and the C<HTML::Element>s
1088 found via C<item_ld> and produces an arrayref of C<HTML::Element>s which will
1089 eventually be spliced into the container.
1091 Note that this subroutine MUST return the new items. This is done
1092 So that more items than were passed in can be returned. This is
1093 useful when, for example, you must return 2 dts for an input data item.
1094 And when would you do this? When a single term has multiple spellings
1097 default: expects C<item_data> to be an arrayref of two elements and
1098 C<item_elems> to be an arrayref of two C<HTML::Element>s. It replaces the
1099 content of the C<HTML::Element>s with the C<item_data>.
1103 After building up an array of C<@item_elems>, the subroutine passed as
1104 C<splice> will be given the parent container HTML::Element and the
1105 C<@item_elems>. How the C<@item_elems> end up in the container is up to this
1106 routine: it could put half of them in. It could unshift them or whatever.
1108 default: C<< $container->splice_content(0, 2, @item_elems) >>
1109 In other words, kill the 2 sample elements with the newly generated
1114 So now that we have documented the API, let's see the call we need:
1117 # default wrapper_ld ok.
1118 wrapper_data => \@items,
1119 wrapper_proc => sub {
1120 my ($container) = @_;
1122 # only keep the last 2 dts and dds
1123 my @content_list = $container->content_list;
1124 $container->splice_content(0, @content_list - 2);
1127 # default item_ld is fine.
1128 # default item_data is fine.
1129 # default item_proc is fine.
1131 my ($container, @item_elems) = @_;
1132 $container->unshift_content(@item_elems);
1138 =head2 Tree-Building Methods: Select Unrolling
1140 The C<unroll_select> method has this API:
1142 $tree->unroll_select(
1143 select_label => $id_label,
1144 option_value => $closure, # how to get option value from data row
1145 option_content => $closure, # how to get option content from data row
1146 option_selected => $closure, # boolean to decide if SELECTED
1147 data => $data # the data to be put into the SELECT
1148 data_iter => $closure # the thing that will get a row of data
1153 $tree->unroll_select(
1154 select_label => 'clan_list',
1155 option_value => sub { my $row = shift; $row->clan_id },
1156 option_content => sub { my $row = shift; $row->clan_name },
1157 option_selected => sub { my $row = shift; $row->selected },
1158 data => \@query_results,
1159 data_iter => sub { my $data = shift; $data->next }
1164 =head2 Tree-Building Methods: Table Generation
1166 Matthew Sisk has a much more intuitive (imperative)
1167 way to generate tables via his module
1168 L<HTML::ElementTable|HTML::ElementTable>.
1169 However, for those with callback fever, the following
1170 method is available. First, we look at a nuts and bolts way to build a table
1171 using only standard L<HTML::Tree> API calls. Then the C<table> method
1172 available here is discussed.
1176 package Simple::Class;
1180 my @name = qw(bob bill brian babette bobo bix);
1181 my @age = qw(99 12 44 52 12 43);
1182 my @weight = qw(99 52 80 124 120 230);
1187 bless {}, ref($this) || $this;
1195 age => $age[rand $#age] + int rand 20,
1196 name => shift @name,
1197 weight => $weight[rand $#weight] + int rand 40
1201 Set::Array->new(@data);
1208 =head4 Sample Usage:
1210 my $data = Simple::Class->load_data;
1211 ++$_->{age} for @$data
1213 =head3 Inline Code to Unroll a Table
1219 <table id="load_data">
1221 <tr> <th>name</th><th>age</th><th>weight</th> </tr>
1225 <td id="name"> NATURE BOY RIC FLAIR </td>
1226 <td id="age"> 35 </td>
1227 <td id="weight"> 220 </td>
1236 =head4 The manual way (*NOT* recommended)
1238 require 'simple-class.pl';
1239 use HTML::Seamstress;
1242 my $seamstress = HTML::Seamstress->new_from_file('simple.html');
1245 my $o = Simple::Class->new;
1246 my $data = $o->load_data;
1248 # find the <table> and <tr>
1249 my $table_node = $seamstress->look_down('id', 'load_data');
1250 my $iter_node = $table_node->look_down('id', 'iterate');
1251 my $table_parent = $table_node->parent;
1254 # drop the sample <table> and <tr> from the HTML
1255 # only add them in if there is data in the model
1256 # this is achieved via the $add_table flag
1258 $table_node->detach;
1262 # Get a row of model data
1263 while (my $row = shift @$data) {
1265 # We got row data. Set the flag indicating ok to hook the table into the HTML
1268 # clone the sample <tr>
1269 my $new_iter_node = $iter_node->clone;
1271 # find the tags labeled name age and weight and
1272 # set their content to the row data
1273 $new_iter_node->content_handler($_ => $row->{$_})
1274 for qw(name age weight);
1276 $table_node->push_content($new_iter_node);
1280 # reattach the table to the HTML tree if we loaded data into some table rows
1282 $table_parent->push_content($table_node) if $add_table;
1284 print $seamstress->as_HTML;
1288 =head3 $tree->table() : API call to Unroll a Table
1290 require 'simple-class.pl';
1291 use HTML::Seamstress;
1294 my $seamstress = HTML::Seamstress->new_from_file('simple.html');
1296 my $o = Simple::Class->new;
1300 # tell seamstress where to find the table, via the method call
1301 # ->look_down('id', $gi_table). Seamstress detaches the table from the
1302 # HTML tree automatically if no table rows can be built
1304 gi_table => 'load_data',
1306 # tell seamstress where to find the tr. This is a bit useless as
1307 # the <tr> usually can be found as the first child of the parent
1311 # the model data to be pushed into the table
1313 table_data => $o->load_data,
1315 # the way to take the model data and obtain one row
1316 # if the table data were a hashref, we would do:
1317 # my $key = (keys %$data)[0]; my $val = $data->{$key}; delete $data->{$key}
1319 tr_data => sub { my ($self, $data) = @_;
1323 # the way to take a row of data and fill the <td> tags
1325 td_data => sub { my ($tr_node, $tr_data) = @_;
1326 $tr_node->content_handler($_ => $tr_data->{$_})
1327 for qw(name age weight) }
1332 print $seamstress->as_HTML;
1336 =head4 Looping over Multiple Sample Rows
1342 <table id="load_data" CELLPADDING=8 BORDER=2>
1344 <tr> <th>name</th><th>age</th><th>weight</th> </tr>
1346 <tr id="iterate1" BGCOLOR="white" >
1348 <td id="name"> NATURE BOY RIC FLAIR </td>
1349 <td id="age"> 35 </td>
1350 <td id="weight"> 220 </td>
1353 <tr id="iterate2" BGCOLOR="#CCCC99">
1355 <td id="name"> NATURE BOY RIC FLAIR </td>
1356 <td id="age"> 35 </td>
1357 <td id="weight"> 220 </td>
1366 * Only one change to last API call.
1374 gi_tr => ['iterate1', 'iterate2']
1376 =head3 $tree->table2() : New API Call to Unroll a Table
1378 After 2 or 3 years with C<table()>, I began to develop
1379 production websites with it and decided it needed a cleaner
1380 interface, particularly in the area of handling the fact that
1381 C<id> tags will be the same after cloning a table row.
1383 First, I will give a dry listing of the function's argument parameters.
1384 This will not be educational most likely. A better way to understand how
1385 to use the function is to read through the incremental unrolling of the
1386 function's interface given in conversational style after the dry listing.
1387 But take your pick. It's the same information given in two different
1390 =head4 Dry/technical parameter documentation
1392 C<< $tree->table2(%param) >> takes the following arguments:
1396 =item * C<< table_ld => $look_down >> : optional
1398 How to find the C<table> element in C<$tree>. If C<$look_down> is an
1399 arrayref, then use C<look_down>. If it is a CODE ref, then call it,
1400 passing it C<$tree>.
1402 Defaults to C<< ['_tag' => 'table'] >> if not passed in.
1404 =item * C<< table_data => $tabular_data >> : required
1406 The data to fill the table with. I<Must> be passed in.
1408 =item * C<< table_proc => $code_ref >> : not implemented
1410 A subroutine to do something to the table once it is found.
1411 Not currently implemented. Not obviously necessary. Just
1412 created because there is a C<tr_proc> and C<td_proc>.
1414 =item * C<< tr_ld => $look_down >> : optional
1416 Same as C<table_ld> but for finding the table row elements. Please note
1417 that the C<tr_ld> is done on the table node that was found I<instead>
1418 of the whole HTML tree. This makes sense. The C<tr>s that you want exist
1419 below the table that was just found.
1421 Defaults to C<< ['_tag' => 'tr'] >> if not passed in.
1423 =item * C<< tr_data => $code_ref >> : optional
1425 How to take the C<table_data> and return a row. Defaults to:
1427 sub { my ($self, $data) = @_;
1431 =item * C<< tr_proc => $code_ref >> : optional
1433 Something to do to the table row we are about to add to the
1434 table we are making. Defaults to a routine which makes the C<id>
1438 my ($self, $tr, $tr_data, $tr_base_id, $row_count) = @_;
1439 $tr->attr(id => sprintf "%s_%d", $tr_base_id, $row_count);
1442 =item * C<< td_proc => $code_ref >> : required
1444 This coderef will take the row of data and operate on the C<td> cells that
1445 are children of the C<tr>. See C<t/table2.t> for several usage examples.
1447 Here's a sample one:
1450 my ($tr, $data) = @_;
1451 my @td = $tr->look_down('_tag' => 'td');
1452 for my $i (0..$#td) {
1453 $td[$i]->splice_content(0, 1, $data->[$i]);
1459 =head4 Conversational parameter documentation
1461 The first thing you need is a table. So we need a look down for that. If you
1462 don't give one, it defaults to
1466 What good is a table to display in without data to display?!
1467 So you must supply a scalar representing your tabular
1468 data source. This scalar might be an array reference, a C<next>able iterator,
1469 a DBI statement handle. Whatever it is, it can be iterated through to build
1470 up rows of table data.
1471 These two required fields (the way to find the table and the data to
1472 display in the table) are C<table_ld> and C<table_data>
1473 respectively. A little more on C<table_ld>. If this happens to be a CODE ref,
1475 of the code ref is presumed to return the C<HTML::Element>
1476 representing the table in the HTML tree.
1478 Next, we get the row or rows which serve as sample C<tr> elements by doing
1479 a C<look_down> from the C<table_elem>. While normally one sample row
1480 is enough to unroll a table, consider when you have alternating
1481 table rows. This API call would need one of each row so that it can
1483 sample rows as it loops through the data.
1484 Alternatively, you could always just use one row and
1485 make the necessary changes to the single C<tr> row by
1486 mutating the element in C<tr_proc>,
1487 discussed below. The default C<tr_ld> is
1488 C<< ['_tag' => 'tr'] >> but you can overwrite it. Note well, if you overwrite
1489 it with a subroutine, then it is expected that the subroutine will return
1490 the C<HTML::Element>(s)
1491 which are C<tr> element(s).
1492 The reason a subroutine might be preferred is in the case
1493 that the HTML designers gave you 8 sample C<tr> rows but only one
1494 prototype row is needed.
1495 So you can write a subroutine, to splice out the 7 rows you don't need
1496 and leave the one sample
1497 row remaining so that this API call can clone it and supply it to
1498 the C<tr_proc> and C<td_proc> calls.
1500 Now, as we move through the table rows with table data,
1501 we need to do two different things on
1506 =item * get one row of data from the C<table_data> via C<tr_data>
1508 The default procedure assumes the C<table_data> is an array reference and
1509 shifts a row off of it:
1511 sub { my ($self, $data) = @_;
1515 Your function MUST return undef when there is no more rows to lay out.
1517 =item * take the C<tr> element and mutate it via C<tr_proc>
1519 The default procedure simply makes the id of the table row unique:
1521 sub { my ($self, $tr, $tr_data, $row_count, $root_id) = @_;
1522 $tr->attr(id => sprintf "%s_%d", $root_id, $row_count);
1527 Now that we have our row of data, we call C<td_proc> so that it can
1528 take the data and the C<td> cells in this C<tr> and process them.
1529 This function I<must> be supplied.
1532 =head3 Whither a Table with No Rows
1534 Often when a table has no rows, we want to display a message
1535 indicating this to the view. Use conditional processing to decide what
1539 <table><tr><td>No Data is Good Data</td></tr></table>
1544 <table id="load_data">
1546 <tr> <th>name</th><th>age</th><th>weight</th> </tr>
1550 <td id="name"> NATURE BOY RIC FLAIR </td>
1551 <td id="age"> 35 </td>
1552 <td id="weight"> 220 </td>
1569 =item * L<HTML::Tree>
1571 A perl package for creating and manipulating HTML trees
1573 =item * L<HTML::ElementTable>
1575 An L<HTML::Tree> - based module which allows for manipulation of HTML
1576 trees using cartesian coordinations.
1578 =item * L<HTML::Seamstress>
1580 An L<HTML::Tree> - based module inspired by
1581 XMLC (L<http://xmlc.enhydra.org>), allowing for dynamic
1582 HTML generation via tree rewriting.
1590 currently the API expects the subtrees to survive or be pruned to be
1593 $if_then->highlander2([
1594 under10 => sub { $_[0] < 10} ,
1595 under18 => sub { $_[0] < 18} ,
1600 $branch->look_down(id => 'age')->replace_content($age);
1607 but, it should be more flexible. the C<under10>, and C<under18> are
1608 expected to be ids in the tree... but it is not hard to have a check to
1609 see if this field is an array reference and if it, then to do a look
1612 $if_then->highlander2([
1613 [class => 'under10'] => sub { $_[0] < 10} ,
1614 [class => 'under18'] => sub { $_[0] < 18} ,
1615 [class => 'welcome'] => [
1619 $branch->look_down(id => 'age')->replace_content($age);
1636 Terrence Brannon, E<lt>tbone@cpan.orgE<gt>
1638 Many thanks to BARBIE for his RT bug report.
1640 =head1 COPYRIGHT AND LICENSE
1642 Copyright (C) 2004 by Terrence Brannon
1644 This library is free software; you can redistribute it and/or modify
1645 it under the same terms as Perl itself, either Perl version 5.8.4 or,
1646 at your option, any later version of Perl 5 you may have available.
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