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) = @_;
  
  ## 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|
    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 makes 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};
      $table->{column_group}->[$_] = $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).
      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
      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_ln 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;
## $Date:$
1	wakaba	1.1	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
8			## Step 1
9			my $x_max = 0;
10
11			## Step 2
12			my $y_max = 0;
13			my $y_max_node;
14
15			## Step 3
16			my $table = {
17			#caption
18			column => [],
19			column_group => [],
20			# no \|row\|
21			row_group => [],
22			cell => [],
23			};
24
25			my @has_anchored_cell;
26			my @column_generated_by;
27			my $check_empty_column = sub {
28			for (1..$x_max) {
29			unless ($has_anchored_cell[$_]) {
30			if ($table->{column}->[$_]) {
31			$onerror->(type => 'column with no anchored cell',
32			node => $table->{column}->[$_]->{element});
33			} else {
34			$onerror->(type => 'colspan makes column with no anchored cell',
35			node => $column_generated_by[$_]);
36			}
37			}
38			}
39			}; # $check_empty_column
40
41			## Step 4
42			## "If the table element has no table children, then return the table (which will be empty), and abort these steps."
43			## ISSUE: What is "table children"?
44			my @table_child = @{$table_el->child_nodes};
45			return unless @table_child; # don't call $check_empty_column
46
47			## Step 5, 6, 8
48			my $current_element;
49			my $current_ln;
50			NEXT_CHILD: {
51			$current_element = shift @table_child;
52			if (defined $current_element) {
53			redo NEXT_CHILD unless $current_element->node_type == 1;
54			my $nsuri = $current_element->namespace_uri;
55			redo NEXT_CHILD unless defined $nsuri and
56			$nsuri eq q<http://www.w3.org/1999/xhtml>;
57			$current_ln = $current_element->manakai_local_name;
58
59			if ($current_ln eq 'caption' and not defined $table->{caption}) {
60			## Step 7
61			$table->{caption} = {element => $current_element};
62			redo NEXT_CHILD; # Step 8
63			}
64
65			redo NEXT_CHILD unless {
66			#caption => 1, ## Step 6
67			colgroup => 1,
68			thead => 1,
69			tbody => 1,
70			tfoot => 1,
71			tr => 1,
72			}->{$current_ln};
73			} else {
74			## End of subsection
75			$check_empty_column->();
76			## Step 5 2nd paragraph
77			return $table;
78			}
79			} # NEXT_CHILD
80
81			## ISSUE: Step 9.1 /next column/ is not used.
82
83			## Step 9
84			while ($current_ln eq 'colgroup') { # Step 9, Step 9.5
85			## Step 2: column groups
86			my @col = grep {
87			$_->node_type == 1 and
88			defined $_->namespace_uri and
89			$_->namespace_uri eq q<http://www.w3.org/1999/xhtml> and
90			$_->manakai_local_name eq 'col'
91			} @{$current_element->child_nodes};
92			if (@col) {
93			## Step 1
94			my $x_start = $x_max + 1;
95
96			## Step 2, 6
97			while (@col) {
98			my $current_column = shift @col;
99
100			## Step 3: columns
101			my $span = 1;
102			my $col_span = $current_column->get_attribute_ns (undef, 'span');
103			## Parse non-negative integer
104			if (defined $col_span and $col_span =~ /^[\x09-\x0D\x20]*([0-9]+)/) {
105			$span = $1 \|\| 1;
106			}
107			## ISSUE: If span=0, what is /span/ value?
108
109			## Step 4, 5
110			$table->{column}->[++$x_max] = {element => $current_column} for 1..$span;
111			}
112
113			## Step 7
114			my $cg = {element => $current_element,
115			x => $x_start, y => 1,
116			width => $x_max - $x_start - 1};
117			$table->{column_group}->[$_] = $cg for $x_start .. $x_max;
118			} else { # no <col> children
119			## Step 1
120			my $span = 1;
121			my $col_span = $current_element->get_attribute_ns (undef, 'span');
122			## Parse non-negative integer
123			if (defined $col_span and $col_span =~ /^[\x09-\x0D\x20]*([0-9]+)/) {
124			$span = $1 \|\| 1;
125			}
126			## ISSUE: If span=0, what is /span/ value?
127
128			## Step 2
129			$x_max += $span;
130
131			## Step 3
132			my $cg = {element => $current_element,
133			x => $x_max - $span + 1, y => 1,
134			width => $span};
135			$table->{column_group}->[$_] = $cg for (($x_max - $span + 1) .. $x_max);
136			}
137
138			## Step 3, 4
139			NEXT_CHILD: {
140			$current_element = shift @table_child;
141			if (defined $current_element) {
142			redo NEXT_CHILD unless $current_element->node_type == 1;
143			my $nsuri = $current_element->namespace_uri;
144			redo NEXT_CHILD unless defined $nsuri and
145			$nsuri eq q<http://www.w3.org/1999/xhtml>;
146			$current_ln = $current_element->manakai_local_name;
147
148			redo NEXT_CHILD unless {
149			colgroup => 1,
150			thead => 1,
151			tbody => 1,
152			tfoot => 1,
153			tr => 1,
154			}->{$current_ln};
155			} else {
156			## End of subsection
157			$check_empty_column->();
158			## Step 5 of overall steps 2nd paragraph
159			return $table;
160			}
161			} # NEXT_CHILD
162			}
163
164			## Step 10
165			my $y_current = 0;
166
167			## Step 11
168			my @downward_growing_cells;
169
170			my $growing_downward_growing_cells = sub {
171			## Step 1
172			return unless @downward_growing_cells;
173
174			## Step 2
175			if ($y_max < $y_current) {
176			$y_max++;
177			undef $y_max_node;
178			}
179
180			## Step 3
181			for (@downward_growing_cells) {
182			for my $x ($_->[1] .. ($_->[1] + $_->[2] - 1)) {
183			$table->{cell}->[$x]->[$y_current] = [$_->[0]];
184			$_->[0]->{height}++;
185			}
186			}
187			}; # $growing_downward_growing_cells
188
189			my $process_row = sub {
190			## Step 1
191			$y_current++;
192
193			## Step 2
194			$growing_downward_growing_cells->();
195
196			## Step 3
197			my $x_current = 1;
198
199			## Step 4
200			my $tr = shift;
201			my @tdth = grep {
202			$_->node_type == 1 and
203			defined $_->namespace_uri and
204			$_->namespace_uri eq q<http://www.w3.org/1999/xhtml> and
205			{td => 1, th => 1}->{$_->manakai_local_name}
206			} @{$tr->child_nodes};
207			#return unless @tdth; # redundant with \|while\| below
208
209			## Step 5, 16, 17, 18
210			## ISSUE: Step 18 says "step 5 (cells)" while "cells" is step 6.
211			while (@tdth) {
212			my $current_cell = shift @tdth;
213
214			## Step 6: cells
215			$x_current++
216			while ($x_current <= $x_max and
217			$table->{cell}->[$x_current]->[$y_current]);
218
219			## Step 7
220			if ($x_current > $x_max) {
221			$x_max++;
222			}
223
224			## Step 8
225			## ISSUE: How to parse \|colspan\| is not explicitly specified
226			## (while \|span\| was).
227			my $colspan = 1;
228			my $attr_value = $current_cell->get_attribute_ns (undef, 'colspan');
229			if (defined $attr_value and $attr_value =~ /^[\x09-\x0D\x20]*([0-9]+)/) {
230			$colspan = $1 \|\| 1;
231			}
232
233			## Step 9
234			my $rowspan = 1;
235			## ISSUE: How to parse
236			my $attr_value = $current_cell->get_attribute_ns (undef, 'rowspan');
237			if (defined $attr_value and $attr_value =~ /^[\x09-\x0D\x20]*([0-9]+)/) {
238			$rowspan = $1;
239			}
240
241			## Step 10
242			my $cell_grows_downward;
243			if ($rowspan == 0) {
244			$cell_grows_downward = 1;
245			$rowspan = 1;
246			}
247
248			## Step 11
249			if ($x_max < $x_current + $colspan - 1) {
250			@column_generated_by[$_] = $current_cell
251			for $x_max + 1 .. $x_current + $colspan - 1;
252			$x_max = $x_current + $colspan - 1;
253			}
254
255			## Step 12
256			if ($y_max < $y_current + $rowspan - 1) {
257			$y_max = $y_current + $rowspan - 1;
258			$y_max_node = $current_cell;
259			}
260
261			## Step 13
262			my $cell = {
263			is_header => ($current_ln eq 'th'),
264			element => $current_cell,
265			x => $x_current, y => $y_current,
266			width => $colspan, height => $rowspan,
267			};
268			$has_anchored_cell[$x_current] = 1;
269			for my $x ($x_current .. ($x_current + $colspan - 1)) {
270			for my $y ($y_current .. ($y_current + $rowspan - 1)) {
271			unless ($table->{cell}->[$x]->[$y]) {
272			$table->{cell}->[$x]->[$y] = [$cell];
273			} else {
274			$onerror->(type => "cell overlapping:$x:$y", node => $current_cell);
275			push @{$table->{cell}->[$x]->[$y]}, $cell;
276			}
277			}
278			}
279
280			## Step 14
281			if ($cell_grows_downward) {
282			push @downward_growing_cells, [$cell, $x_current, $colspan];
283			}
284
285			## Step 15
286			$x_current += $colspan;
287			}
288			}; # $process_row
289
290			## Step 12: rows
291			unshift @table_child, $current_element;
292			ROWS: {
293			NEXT_CHILD: {
294			$current_element = shift @table_child;
295			if (defined $current_element) {
296			redo NEXT_CHILD unless $current_element->node_type == 1;
297			my $nsuri = $current_element->namespace_uri;
298			redo NEXT_CHILD unless defined $nsuri and
299			$nsuri eq q<http://www.w3.org/1999/xhtml>;
300			$current_ln = $current_element->manakai_local_name;
301
302			redo NEXT_CHILD unless {
303			thead => 1,
304			tbody => 1,
305			tfoot => 1,
306			tr => 1,
307			}->{$current_ln};
308			} else {
309			## Step 10 2nd sentense
310			if ($y_current != $y_max) {
311			$onerror->(type => 'rowspan expands table',
312			node => $y_max_node);
313			}
314			## End of subsection
315			$check_empty_column->();
316			## Step 5 2nd paragraph
317			return $table;
318			}
319			} # NEXT_CHILD
320
321			## Step 13
322			if ($current_ln eq 'tr') {
323			$process_row->($current_element);
324			redo ROWS;
325			}
326
327			## Step 14
328			## Ending a row group
329			## Step 1
330			if ($y_current < $y_max) {
331			$onerror->(type => 'rowspan expands table', node => $y_max_node);
332			}
333			## Step 2
334			while ($y_current < $y_max) {
335			## Step 1
336			$y_current++;
337			$growing_downward_growing_cells->();
338			}
339			## Step 3
340			@downward_growing_cells = ();
341
342			## Step 15
343			my $y_start = $y_max + 1;
344
345			## Step 16
346			for (grep {
347			$_->node_type == 1 and
348			defined $_->namespace_uri and
349			$_->namespace_uri eq q<http://www.w3.org/1999/xhtml> and
350			$_->manakai_local_name eq 'tr'
351			} @{$current_element->child_nodes}) {
352			$process_row->($_);
353			}
354
355			## Step 17
356			if ($y_max >= $y_start) {
357			my $rg = {element => $current_element,
358			x => 1, y => $y_start,
359			height => $y_max - $y_start + 1};
360			$table->{row_group}->[$_] = $rg for $y_start .. $y_max;
361			}
362
363			## Step 18
364			## Ending a row group
365			## Step 1
366			if ($y_current < $y_max) {
367			$onerror->(type => 'rowspan expands table', node => $y_max_node);
368			}
369			## Step 2
370			while ($y_current < $y_max) {
371			## Step 1
372			$y_current++;
373			$growing_downward_growing_cells->();
374			}
375			## Step 3
376			@downward_growing_cells = ();
377
378			## Step 19
379			redo ROWS; # Step 12
380			} # ROWS
381			} # form_table
382
383			## TODO: Implement scope="" algorithm
384
385			1;
386			## $Date:$