whatpm/Whatpm/HTMLTable.pm

package Whatpm::HTMLTable;
use strict;

## An implementation of "Forming a table" algorithm in HTML5
sub form_table ($$$) {
  my (undef, $table_el, $onerror) = @_;
  $onerror ||= sub { };
  
  ## Step 1
  my $x_max = 0;

  ## Step 2
  my $y_max = 0;
  my $y_max_node;
  
  ## Step 3
  my $table = {
    #caption
    column => [],
    column_group => [],
    # no |row| since HTML5 algorithm doesn't associate rows with <tr>s
    row_group => [],
    cell => [],
  };
  
  my @has_anchored_cell;
  my @column_generated_by;
  my $check_empty_column = sub {
    for (1..$x_max) {
      unless ($has_anchored_cell[$_]) {
        if ($table->{column}->[$_]) {
          $onerror->(type => 'column with no anchored cell',
                     node => $table->{column}->[$_]->{element});
        } else {
          $onerror->(type => 'colspan creates column with no anchored cell',
                     node => $column_generated_by[$_]);
        }
      }
    }
  }; # $check_empty_column
  
  ## Step 4
  ## "If the table element has no table children, then return the table (which will be empty), and abort these steps."
  ## ISSUE: What is "table children"?
  my @table_child = @{$table_el->child_nodes};
  return unless @table_child; # don't call $check_empty_column

  ## Step 5, 6, 8
  my $current_element;
  my $current_ln;
  NEXT_CHILD: {
    $current_element = shift @table_child;
    if (defined $current_element) {
      redo NEXT_CHILD unless $current_element->node_type == 1;
      my $nsuri = $current_element->namespace_uri;
      redo NEXT_CHILD unless defined $nsuri and
        $nsuri eq q<http://www.w3.org/1999/xhtml>;
      $current_ln = $current_element->manakai_local_name;

      if ($current_ln eq 'caption' and not defined $table->{caption}) {
        ## Step 7
        $table->{caption} = {element => $current_element};
        redo NEXT_CHILD; # Step 8
      }

      redo NEXT_CHILD unless {
        #caption => 1, ## Step 6
        colgroup => 1,
        thead => 1,
        tbody => 1,
        tfoot => 1,
        tr => 1,
      }->{$current_ln};
    } else {
      ## End of subsection
      $check_empty_column->();
      ## Step 5 2nd paragraph
      return $table;
    }
  } # NEXT_CHILD

  ## ISSUE: Step 9.1 /next column/ is not used.

  ## Step 9
  while ($current_ln eq 'colgroup') { # Step 9, Step 9.5
    ## Step 2: column groups
    my @col = grep {
      $_->node_type == 1 and
      defined $_->namespace_uri and
      $_->namespace_uri eq q<http://www.w3.org/1999/xhtml> and
      $_->manakai_local_name eq 'col'
    } @{$current_element->child_nodes};
    if (@col) {
      ## Step 1
      my $x_start = $x_max + 1;
      
      ## Step 2, 6
      while (@col) {
        my $current_column = shift @col;
        
        ## Step 3: columns
        my $span = 1;
        my $col_span = $current_column->get_attribute_ns (undef, 'span');
        ## Parse non-negative integer
        if (defined $col_span and $col_span =~ /^[\x09-\x0D\x20]*([0-9]+)/) {
          $span = $1 || 1;
        }
        ## ISSUE: If span=0, what is /span/ value?
        
        ## Step 4, 5
        $table->{column}->[++$x_max] = {element => $current_column} for 1..$span;
      }
      
      ## Step 7
      my $cg = {element => $current_element,
                x => $x_start, y => 1,
                width => $x_max - $x_start - 1}; ## ISSUE: Spec incorrect
      $cg->{width} = $x_max - $x_start + 1;
      $table->{column_group}->[$_] = $cg for $x_start .. $x_max;
    } else { # no <col> children
      ## Step 1
      my $span = 1;
      my $col_span = $current_element->get_attribute_ns (undef, 'span');
      ## Parse non-negative integer
      if (defined $col_span and $col_span =~ /^[\x09-\x0D\x20]*([0-9]+)/) {
        $span = $1 || 1;
      }
      ## ISSUE: If span=0, what is /span/ value?
      
      ## Step 2
      $x_max += $span;
      
      ## Step 3
      my $cg = {element => $current_element,
                x => $x_max - $span + 1, y => 1,
                width => $span};
      $table->{column_group}->[$_] = $cg for (($x_max - $span + 1) .. $x_max);
    }
    
    ## Step 3, 4
    NEXT_CHILD: {
      $current_element = shift @table_child;
      if (defined $current_element) {
        redo NEXT_CHILD unless $current_element->node_type == 1;
        my $nsuri = $current_element->namespace_uri;
        redo NEXT_CHILD unless defined $nsuri and
          $nsuri eq q<http://www.w3.org/1999/xhtml>;
        $current_ln = $current_element->manakai_local_name;
        
        redo NEXT_CHILD unless {
          colgroup => 1,
          thead => 1,
          tbody => 1,
          tfoot => 1,
          tr => 1,
        }->{$current_ln};
      } else {
        ## End of subsection
        $check_empty_column->();
        ## Step 5 of overall steps 2nd paragraph
        return $table;
      }
    } # NEXT_CHILD
  }

  ## Step 10
  my $y_current = 0;

  ## Step 11
  my @downward_growing_cells;

  my $growing_downward_growing_cells = sub {
    ## Step 1
    return unless @downward_growing_cells;

    ## Step 2
    if ($y_max < $y_current) {
      $y_max++;
      undef $y_max_node;
    }

    ## Step 3
    for (@downward_growing_cells) {
      for my $x ($_->[1] .. ($_->[1] + $_->[2] - 1)) {
        $table->{cell}->[$x]->[$y_current] = [$_->[0]];
        $_->[0]->{height}++;
      }
    }
  }; # $growing_downward_growing_cells

  my $process_row = sub {
    ## Step 1
    $y_current++;
    
    ## Step 2
    $growing_downward_growing_cells->();
    
    ## Step 3
    my $x_current = 1;

    ## Step 4
    my $tr = shift;
    my @tdth = grep {
      $_->node_type == 1 and
      defined $_->namespace_uri and
      $_->namespace_uri eq q<http://www.w3.org/1999/xhtml> and
      {td => 1, th => 1}->{$_->manakai_local_name}
    } @{$tr->child_nodes};
    #return unless @tdth; # redundant with |while| below

    ## Step 5, 16, 17, 18
    ## ISSUE: Step 18 says "step 5 (cells)" while "cells" is step 6.
    while (@tdth) {
      my $current_cell = shift @tdth;
    
      ## Step 6: cells
      $x_current++
        while ($x_current <= $x_max and
               $table->{cell}->[$x_current]->[$y_current]);

      ## Step 7
      if ($x_current > $x_max) {
        $x_max++;
      }

      ## Step 8
      ## ISSUE: How to parse |colspan| is not explicitly specified
      ## (while |span| was).
      ## <http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2006-November/007981.html>
      my $colspan = 1;
      my $attr_value = $current_cell->get_attribute_ns (undef, 'colspan');
      if (defined $attr_value and $attr_value =~ /^[\x09-\x0D\x20]*([0-9]+)/) {
        $colspan = $1 || 1;
      }
      
      ## Step 9
      my $rowspan = 1;
      ## ISSUE: How to parse
      ## <http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2006-November/007981.html>
      my $attr_value = $current_cell->get_attribute_ns (undef, 'rowspan');
      if (defined $attr_value and $attr_value =~ /^[\x09-\x0D\x20]*([0-9]+)/) {
        $rowspan = $1;
      }
      
      ## Step 10
      my $cell_grows_downward;
      if ($rowspan == 0) {
        $cell_grows_downward = 1;
        $rowspan = 1;
      }
      
      ## Step 11
      if ($x_max < $x_current + $colspan - 1) { 
        @column_generated_by[$_] = $current_cell
          for $x_max + 1 .. $x_current + $colspan - 1;
        $x_max = $x_current + $colspan - 1;
      }
      
      ## Step 12
      if ($y_max < $y_current + $rowspan - 1) {
        $y_max = $y_current + $rowspan - 1;
        $y_max_node = $current_cell;
      }
      
      ## Step 13
      my $cell = {
                  is_header => ($current_cell->manakai_local_name eq 'th'),
                  element => $current_cell,
                  x => $x_current, y => $y_current,
                  width => $colspan, height => $rowspan,
                 };
      $has_anchored_cell[$x_current] = 1;
      for my $x ($x_current .. ($x_current + $colspan - 1)) {
        for my $y ($y_current .. ($y_current + $rowspan - 1)) {
          unless ($table->{cell}->[$x]->[$y]) {
            $table->{cell}->[$x]->[$y] = [$cell];
          } else {
            $onerror->(type => "cell overlapping:$x:$y", node => $current_cell);
            push @{$table->{cell}->[$x]->[$y]}, $cell;
          }
        }
      }
      
      ## Step 14
      if ($cell_grows_downward) {
        push @downward_growing_cells, [$cell, $x_current, $colspan];
      }
      
      ## Step 15
      $x_current += $colspan;
    }
  }; # $process_row

  ## Step 12: rows
  unshift @table_child, $current_element;
  ROWS: {
    NEXT_CHILD: {
      $current_element = shift @table_child;
      if (defined $current_element) {
        redo NEXT_CHILD unless $current_element->node_type == 1;
        my $nsuri = $current_element->namespace_uri;
        redo NEXT_CHILD unless defined $nsuri and
          $nsuri eq q<http://www.w3.org/1999/xhtml>;
        $current_ln = $current_element->manakai_local_name;
      
        redo NEXT_CHILD unless {
          thead => 1,
          tbody => 1,
          tfoot => 1,
          tr => 1,
        }->{$current_ln};
      } else {
        ## Step 10 2nd sentense
        if ($y_current != $y_max) {
          $onerror->(type => 'rowspan expands table',
                     node => $y_max_node);
        }
        ## End of subsection
        $check_empty_column->();
        ## Step 5 2nd paragraph
        return $table;
      }
    } # NEXT_CHILD

    ## Step 13
    if ($current_ln eq 'tr') {
      $process_row->($current_element);
      redo ROWS;
    }

    ## Step 14
    ## Ending a row group
      ## Step 1
      if ($y_current < $y_max) {
        $onerror->(type => 'rowspan expands table', node => $y_max_node);
      }
      ## Step 2
      while ($y_current < $y_max) {
        ## Step 1
        $y_current++;
        $growing_downward_growing_cells->();
      }
      ## Step 3
      @downward_growing_cells = ();
      
    ## Step 15
    my $y_start = $y_max + 1;

    ## Step 16
    for (grep {
      $_->node_type == 1 and
      defined $_->namespace_uri and
      $_->namespace_uri eq q<http://www.w3.org/1999/xhtml> and
      $_->manakai_local_name eq 'tr'
    } @{$current_element->child_nodes}) {
      $process_row->($_);
    }

    ## Step 17
    if ($y_max >= $y_start) {
      my $rg = {element => $current_element,
                x => 1, y => $y_start,
                height => $y_max - $y_start + 1};
      $table->{row_group}->[$_] = $rg for $y_start .. $y_max;
    }

    ## Step 18
    ## Ending a row group
      ## Step 1
      if ($y_current < $y_max) {
        $onerror->(type => 'rowspan expands table', node => $y_max_node);
      }
      ## Step 2
      while ($y_current < $y_max) {
        ## Step 1
        $y_current++;
        $growing_downward_growing_cells->();
      }
      ## Step 3
      @downward_growing_cells = ();

    ## Step 19
    redo ROWS; # Step 12
  } # ROWS
} # form_table

## TODO: Implement scope="" algorithm

1;
## $Date: 2007/05/27 10:28:01 $
1	package Whatpm::HTMLTable;
2	use strict;
3
4	## An implementation of "Forming a table" algorithm in HTML5
5	sub form_table ($$$) {
6	my (undef, $table_el, $onerror) = @_;
7	$onerror \|\|= sub { };
8
9	## Step 1
10	my $x_max = 0;
11
12	## Step 2
13	my $y_max = 0;
14	my $y_max_node;
15
16	## Step 3
17	my $table = {
18	#caption
19	column => [],
20	column_group => [],
21	# no \|row\| since HTML5 algorithm doesn't associate rows with <tr>s
22	row_group => [],
23	cell => [],
24	};
25
26	my @has_anchored_cell;
27	my @column_generated_by;
28	my $check_empty_column = sub {
29	for (1..$x_max) {
30	unless ($has_anchored_cell[$_]) {
31	if ($table->{column}->[$_]) {
32	$onerror->(type => 'column with no anchored cell',
33	node => $table->{column}->[$_]->{element});
34	} else {
35	$onerror->(type => 'colspan creates column with no anchored cell',
36	node => $column_generated_by[$_]);
37	}
38	}
39	}
40	}; # $check_empty_column
41
42	## Step 4
43	## "If the table element has no table children, then return the table (which will be empty), and abort these steps."
44	## ISSUE: What is "table children"?
45	my @table_child = @{$table_el->child_nodes};
46	return unless @table_child; # don't call $check_empty_column
47
48	## Step 5, 6, 8
49	my $current_element;
50	my $current_ln;
51	NEXT_CHILD: {
52	$current_element = shift @table_child;
53	if (defined $current_element) {
54	redo NEXT_CHILD unless $current_element->node_type == 1;
55	my $nsuri = $current_element->namespace_uri;
56	redo NEXT_CHILD unless defined $nsuri and
57	$nsuri eq q<http://www.w3.org/1999/xhtml>;
58	$current_ln = $current_element->manakai_local_name;
59
60	if ($current_ln eq 'caption' and not defined $table->{caption}) {
61	## Step 7
62	$table->{caption} = {element => $current_element};
63	redo NEXT_CHILD; # Step 8
64	}
65
66	redo NEXT_CHILD unless {
67	#caption => 1, ## Step 6
68	colgroup => 1,
69	thead => 1,
70	tbody => 1,
71	tfoot => 1,
72	tr => 1,
73	}->{$current_ln};
74	} else {
75	## End of subsection
76	$check_empty_column->();
77	## Step 5 2nd paragraph
78	return $table;
79	}
80	} # NEXT_CHILD
81
82	## ISSUE: Step 9.1 /next column/ is not used.
83
84	## Step 9
85	while ($current_ln eq 'colgroup') { # Step 9, Step 9.5
86	## Step 2: column groups
87	my @col = grep {
88	$_->node_type == 1 and
89	defined $_->namespace_uri and
90	$_->namespace_uri eq q<http://www.w3.org/1999/xhtml> and
91	$_->manakai_local_name eq 'col'
92	} @{$current_element->child_nodes};
93	if (@col) {
94	## Step 1
95	my $x_start = $x_max + 1;
96
97	## Step 2, 6
98	while (@col) {
99	my $current_column = shift @col;
100
101	## Step 3: columns
102	my $span = 1;
103	my $col_span = $current_column->get_attribute_ns (undef, 'span');
104	## Parse non-negative integer
105	if (defined $col_span and $col_span =~ /^[\x09-\x0D\x20]*([0-9]+)/) {
106	$span = $1 \|\| 1;
107	}
108	## ISSUE: If span=0, what is /span/ value?
109
110	## Step 4, 5
111	$table->{column}->[++$x_max] = {element => $current_column} for 1..$span;
112	}
113
114	## Step 7
115	my $cg = {element => $current_element,
116	x => $x_start, y => 1,
117	width => $x_max - $x_start - 1}; ## ISSUE: Spec incorrect
118	$cg->{width} = $x_max - $x_start + 1;
119	$table->{column_group}->[$_] = $cg for $x_start .. $x_max;
120	} else { # no <col> children
121	## Step 1
122	my $span = 1;
123	my $col_span = $current_element->get_attribute_ns (undef, 'span');
124	## Parse non-negative integer
125	if (defined $col_span and $col_span =~ /^[\x09-\x0D\x20]*([0-9]+)/) {
126	$span = $1 \|\| 1;
127	}
128	## ISSUE: If span=0, what is /span/ value?
129
130	## Step 2
131	$x_max += $span;
132
133	## Step 3
134	my $cg = {element => $current_element,
135	x => $x_max - $span + 1, y => 1,
136	width => $span};
137	$table->{column_group}->[$_] = $cg for (($x_max - $span + 1) .. $x_max);
138	}
139
140	## Step 3, 4
141	NEXT_CHILD: {
142	$current_element = shift @table_child;
143	if (defined $current_element) {
144	redo NEXT_CHILD unless $current_element->node_type == 1;
145	my $nsuri = $current_element->namespace_uri;
146	redo NEXT_CHILD unless defined $nsuri and
147	$nsuri eq q<http://www.w3.org/1999/xhtml>;
148	$current_ln = $current_element->manakai_local_name;
149
150	redo NEXT_CHILD unless {
151	colgroup => 1,
152	thead => 1,
153	tbody => 1,
154	tfoot => 1,
155	tr => 1,
156	}->{$current_ln};
157	} else {
158	## End of subsection
159	$check_empty_column->();
160	## Step 5 of overall steps 2nd paragraph
161	return $table;
162	}
163	} # NEXT_CHILD
164	}
165
166	## Step 10
167	my $y_current = 0;
168
169	## Step 11
170	my @downward_growing_cells;
171
172	my $growing_downward_growing_cells = sub {
173	## Step 1
174	return unless @downward_growing_cells;
175
176	## Step 2
177	if ($y_max < $y_current) {
178	$y_max++;
179	undef $y_max_node;
180	}
181
182	## Step 3
183	for (@downward_growing_cells) {
184	for my $x ($_->[1] .. ($_->[1] + $_->[2] - 1)) {
185	$table->{cell}->[$x]->[$y_current] = [$_->[0]];
186	$_->[0]->{height}++;
187	}
188	}
189	}; # $growing_downward_growing_cells
190
191	my $process_row = sub {
192	## Step 1
193	$y_current++;
194
195	## Step 2
196	$growing_downward_growing_cells->();
197
198	## Step 3
199	my $x_current = 1;
200
201	## Step 4
202	my $tr = shift;
203	my @tdth = grep {
204	$_->node_type == 1 and
205	defined $_->namespace_uri and
206	$_->namespace_uri eq q<http://www.w3.org/1999/xhtml> and
207	{td => 1, th => 1}->{$_->manakai_local_name}
208	} @{$tr->child_nodes};
209	#return unless @tdth; # redundant with \|while\| below
210
211	## Step 5, 16, 17, 18
212	## ISSUE: Step 18 says "step 5 (cells)" while "cells" is step 6.
213	while (@tdth) {
214	my $current_cell = shift @tdth;
215
216	## Step 6: cells
217	$x_current++
218	while ($x_current <= $x_max and
219	$table->{cell}->[$x_current]->[$y_current]);
220
221	## Step 7
222	if ($x_current > $x_max) {
223	$x_max++;
224	}
225
226	## Step 8
227	## ISSUE: How to parse \|colspan\| is not explicitly specified
228	## (while \|span\| was).
229	## <http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2006-November/007981.html>
230	my $colspan = 1;
231	my $attr_value = $current_cell->get_attribute_ns (undef, 'colspan');
232	if (defined $attr_value and $attr_value =~ /^[\x09-\x0D\x20]*([0-9]+)/) {
233	$colspan = $1 \|\| 1;
234	}
235
236	## Step 9
237	my $rowspan = 1;
238	## ISSUE: How to parse
239	## <http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2006-November/007981.html>
240	my $attr_value = $current_cell->get_attribute_ns (undef, 'rowspan');
241	if (defined $attr_value and $attr_value =~ /^[\x09-\x0D\x20]*([0-9]+)/) {
242	$rowspan = $1;
243	}
244
245	## Step 10
246	my $cell_grows_downward;
247	if ($rowspan == 0) {
248	$cell_grows_downward = 1;
249	$rowspan = 1;
250	}
251
252	## Step 11
253	if ($x_max < $x_current + $colspan - 1) {
254	@column_generated_by[$_] = $current_cell
255	for $x_max + 1 .. $x_current + $colspan - 1;
256	$x_max = $x_current + $colspan - 1;
257	}
258
259	## Step 12
260	if ($y_max < $y_current + $rowspan - 1) {
261	$y_max = $y_current + $rowspan - 1;
262	$y_max_node = $current_cell;
263	}
264
265	## Step 13
266	my $cell = {
267	is_header => ($current_cell->manakai_local_name eq 'th'),
268	element => $current_cell,
269	x => $x_current, y => $y_current,
270	width => $colspan, height => $rowspan,
271	};
272	$has_anchored_cell[$x_current] = 1;
273	for my $x ($x_current .. ($x_current + $colspan - 1)) {
274	for my $y ($y_current .. ($y_current + $rowspan - 1)) {
275	unless ($table->{cell}->[$x]->[$y]) {
276	$table->{cell}->[$x]->[$y] = [$cell];
277	} else {
278	$onerror->(type => "cell overlapping:$x:$y", node => $current_cell);
279	push @{$table->{cell}->[$x]->[$y]}, $cell;
280	}
281	}
282	}
283
284	## Step 14
285	if ($cell_grows_downward) {
286	push @downward_growing_cells, [$cell, $x_current, $colspan];
287	}
288
289	## Step 15
290	$x_current += $colspan;
291	}
292	}; # $process_row
293
294	## Step 12: rows
295	unshift @table_child, $current_element;
296	ROWS: {
297	NEXT_CHILD: {
298	$current_element = shift @table_child;
299	if (defined $current_element) {
300	redo NEXT_CHILD unless $current_element->node_type == 1;
301	my $nsuri = $current_element->namespace_uri;
302	redo NEXT_CHILD unless defined $nsuri and
303	$nsuri eq q<http://www.w3.org/1999/xhtml>;
304	$current_ln = $current_element->manakai_local_name;
305
306	redo NEXT_CHILD unless {
307	thead => 1,
308	tbody => 1,
309	tfoot => 1,
310	tr => 1,
311	}->{$current_ln};
312	} else {
313	## Step 10 2nd sentense
314	if ($y_current != $y_max) {
315	$onerror->(type => 'rowspan expands table',
316	node => $y_max_node);
317	}
318	## End of subsection
319	$check_empty_column->();
320	## Step 5 2nd paragraph
321	return $table;
322	}
323	} # NEXT_CHILD
324
325	## Step 13
326	if ($current_ln eq 'tr') {
327	$process_row->($current_element);
328	redo ROWS;
329	}
330
331	## Step 14
332	## Ending a row group
333	## Step 1
334	if ($y_current < $y_max) {
335	$onerror->(type => 'rowspan expands table', node => $y_max_node);
336	}
337	## Step 2
338	while ($y_current < $y_max) {
339	## Step 1
340	$y_current++;
341	$growing_downward_growing_cells->();
342	}
343	## Step 3
344	@downward_growing_cells = ();
345
346	## Step 15
347	my $y_start = $y_max + 1;
348
349	## Step 16
350	for (grep {
351	$_->node_type == 1 and
352	defined $_->namespace_uri and
353	$_->namespace_uri eq q<http://www.w3.org/1999/xhtml> and
354	$_->manakai_local_name eq 'tr'
355	} @{$current_element->child_nodes}) {
356	$process_row->($_);
357	}
358
359	## Step 17
360	if ($y_max >= $y_start) {
361	my $rg = {element => $current_element,
362	x => 1, y => $y_start,
363	height => $y_max - $y_start + 1};
364	$table->{row_group}->[$_] = $rg for $y_start .. $y_max;
365	}
366
367	## Step 18
368	## Ending a row group
369	## Step 1
370	if ($y_current < $y_max) {
371	$onerror->(type => 'rowspan expands table', node => $y_max_node);
372	}
373	## Step 2
374	while ($y_current < $y_max) {
375	## Step 1
376	$y_current++;
377	$growing_downward_growing_cells->();
378	}
379	## Step 3
380	@downward_growing_cells = ();
381
382	## Step 19
383	redo ROWS; # Step 12
384	} # ROWS
385	} # form_table
386
387	## TODO: Implement scope="" algorithm
388
389	1;
390	## $Date: 2007/05/27 10:28:01 $