File Coverage

blib/lib/Mojo/DOM58/_HTML.pm

Criterion	Covered	Total	%
statement	113	115	98.2
branch	97	100	97.0
condition	39	46	84.7
subroutine	18	18	100.0
pod	0	7	0.0
total	267	286	93.3

package Mojo::DOM58::_HTML;

# This file is part of Mojo::DOM58 which is released under:
#   The Artistic License 2.0 (GPL Compatible)
# See the documentation for Mojo::DOM58 for full license details.

use strict;
use warnings;
use Exporter 'import';
use Mojo::DOM58::Entities qw(html_attr_unescape html_escape html_unescape);
use Scalar::Util 'weaken';

our $VERSION = '2.000';

our @EXPORT_OK = 'tag_to_html';

my $ATTR_RE = qr/
  ([^<>=\s\/]+|\/)                         # Key
  (?:
    \s*=\s*
    (?s:(?:"(.*?)")|(?:'(.*?)')|([^>\s]*)) # Value
  )?
  \s*
/x;
my $TOKEN_RE = qr/
  ([^<]+)?                                            # Text
  (?:
    <(?:
      !(?:
        DOCTYPE(
        \s+\w+                                        # Doctype
        (?:(?:\s+\w+)?(?:\s+(?:"[^"]*"|'[^']*'))+)?   # External ID
        (?:\s+\[.+?\])?                               # Int Subset
        \s*)
      |
        --(.*?)--\s*                                  # Comment
      |
        \[CDATA\[(.*?)\]\]                            # CDATA
      )
    |
      \?(.*?)\?                                       # Processing Instruction
    |
      \s*([^<>\s]+\s*(?>(?:$ATTR_RE){0,32766})*)       # Tag
      # Workaround for perl's limit of * to {0,32767}
    )>
  |
    (<)                                               # Runaway "<"
  )??
/xis;

# HTML elements that only contain raw text
my %RAW = map { $_ => 1 } qw(script style);

# HTML elements that only contain raw text and entities
my %RCDATA = map { $_ => 1 } qw(title textarea);

# HTML elements with optional end tags
my %END = (body => 'head', optgroup => 'optgroup', option => 'option');

# HTML elements that break paragraphs
$END{$_} = 'p' for
  qw(address article aside blockquote details dialog div dl fieldset),
  qw(figcaption figure footer form h1 h2 h3 h4 h5 h6 header hgroup hr main),
  qw(menu nav ol p pre section table ul);

# HTML table elements with optional end tags
my %TABLE = map { $_ => 1 } qw(colgroup tbody td tfoot th thead tr);

# HTML elements with optional end tags and scoping rules
my %CLOSE
  = (li => [{li => 1}, {ul => 1, ol => 1}], tr => [{tr => 1}, {table => 1}]);
$CLOSE{$_} = [\%TABLE, {table => 1}] for qw(colgroup tbody tfoot thead);
$CLOSE{$_} = [{dd => 1, dt => 1}, {dl    => 1}] for qw(dd dt);
$CLOSE{$_} = [{rp => 1, rt => 1}, {ruby  => 1}] for qw(rp rt);
$CLOSE{$_} = [{th => 1, td => 1}, {table => 1}] for qw(td th);

# HTML elements without end tags
my %EMPTY = map { $_ => 1 } (
  qw(area base br col embed hr img input keygen link menuitem meta param),
  qw(source track wbr)
);

# HTML elements categorized as phrasing content (and obsolete inline elements)
my @PHRASING = (
  qw(a abbr area audio b bdi bdo br button canvas cite code data datalist),
  qw(del dfn em embed i iframe img input ins kbd keygen label link map mark),
  qw(math meta meter noscript object output picture progress q ruby s samp),
  qw(script select slot small span strong sub sup svg template textarea time u),
  qw(var video wbr)
);
my @OBSOLETE = qw(acronym applet basefont big font strike tt);
my %PHRASING = map { $_ => 1 } @OBSOLETE, @PHRASING;

# HTML elements that don't get their self-closing flag acknowledged
my %BLOCK = map { $_ => 1 } (
  qw(a address applet article aside b big blockquote body button caption),
  qw(center code col colgroup dd details dialog dir div dl dt em fieldset),
  qw(figcaption figure font footer form frameset h1 h2 h3 h4 h5 h6 head),
  qw(header hgroup html i iframe li listing main marquee menu nav nobr),
  qw(noembed noframes noscript object ol optgroup option p plaintext pre rp),
  qw(rt s script section select small strike strong style summary table),
  qw(tbody td template textarea tfoot th thead title tr tt u ul xmp)
);

sub new {
  my $class = shift;
  bless @_ ? @_ > 1 ? {@_} : {%{$_[0]}} : {}, ref $class || $class;
}

sub tag { shift->tree(['root', _tag(@_)]) }

sub tag_to_html { _render(_tag(@_), undef) }

sub tree {
  my $self = shift;
  return exists $self->{tree} ? $self->{tree} : ($self->{tree} = ['root']) unless @_;
  $self->{tree} = shift;
  return $self;
}

sub xml {
  my $self = shift;
  return $self->{xml} unless @_;
  $self->{xml} = shift;
  return $self;
}

sub parse {
  my ($self, $html) = (shift, "$_[0]");

  my $xml = $self->xml;
  my $current = my $tree = ['root'];
  while ($html =~ /\G$TOKEN_RE/gcso) {
    my ($text, $doctype, $comment, $cdata, $pi, $tag, $runaway)
      = ($1, $2, $3, $4, $5, $6, $11);

    # Text (and runaway "<")
    $text .= '<' if defined $runaway;
    _node($current, 'text', html_unescape $text) if defined $text;

    # Tag
    if (defined $tag) {

      # End
      if ($tag =~ /^\/\s*(\S+)/) { _end($xml ? $1 : lc $1, $xml, \$current) }

      # Start
      elsif ($tag =~ m!^([^\s/]+)([\s\S]*)!) {
        my ($start, $attr) = ($xml ? $1 : lc $1, $2);

        # Attributes
        my (%attrs, $closing);
        while ($attr =~ /$ATTR_RE/go) {
          my $key = $xml ? $1 : lc $1;
          my $value = defined($2) ? $2 : defined($3) ? $3 : $4;

          # Empty tag
          ++$closing and next if $key eq '/';

          $attrs{$key} = defined $value ? html_attr_unescape $value : $value;
        }

        # "image" is an alias for "img"
        $start = 'img' if !$xml && $start eq 'image';
        _start($start, \%attrs, $xml, \$current);

        # Element without end tag (self-closing)
        _end($start, $xml, \$current)
          if !$xml && $EMPTY{$start} || ($xml || !$BLOCK{$start}) && $closing;

        # Raw text elements
        next if $xml || !$RAW{$start} && !$RCDATA{$start};
        next unless $html =~ m!\G(.*?)<\s*/\s*\Q$start\E\s*>!gcsi;
        _node($current, 'raw', $RCDATA{$start} ? html_unescape $1 : $1);
        _end($start, 0, \$current);
      }
    }

    # DOCTYPE
    elsif (defined $doctype) { _node($current, 'doctype', $doctype) }

    # Comment
    elsif (defined $comment) { _node($current, 'comment', $comment) }

    # CDATA
    elsif (defined $cdata) { _node($current, 'cdata', $cdata) }

    # Processing instruction (try to detect XML)
    elsif (defined $pi) {
      $self->xml($xml = 1) if !exists $self->{xml} && $pi =~ /xml/i;
      _node($current, 'pi', $pi);
    }
  }

  return $self->tree($tree);
}

sub render { _render($_[0]->tree, $_[0]->xml) }

sub _end {
  my ($end, $xml, $current) = @_;

  # Search stack for start tag
  my $next = $$current;
  do {

    # Ignore useless end tag
    return if $next->[0] eq 'root';

    # Right tag
    return $$current = $next->[3] if $next->[1] eq $end;

    # Phrasing content can only cross phrasing content
    return if !$xml && $PHRASING{$end} && !$PHRASING{$next->[1]};

  } while $next = $next->[3];
}

sub _node {
  my ($current, $type, $content) = @_;
  push @$current, my $new = [$type, $content, $current];
  weaken $new->[2];
}

sub _render {
  my ($tree, $xml) = @_;

  # Tag
  my $type = $tree->[0];
  if ($type eq 'tag') {

    # Start tag
    my $tag    = $tree->[1];
    my $result = "<$tag";

    # Attributes
    for my $key (sort keys %{$tree->[2]}) {
      my $value = $tree->[2]{$key};
      $result .= $xml ? qq{ $key="$key"} : " $key" and next
        unless defined $value;
      $result .= qq{ $key="} . html_escape($value) . '"';
    }

    # No children
    return $xml ? "$result />" : $EMPTY{$tag} ? "$result>" : "$result>"
      unless $tree->[4];

    # Children
    no warnings 'recursion';
    $result .= '>' . join '', map { _render($_, $xml) } @$tree[4 .. $#$tree];

    # End tag
    return "$result";
  }

  # Text (escaped)
  return html_escape($tree->[1]) if $type eq 'text';

  # Raw text
  return $tree->[1] if $type eq 'raw';

  # Root
  return join '', map { _render($_, $xml) } @$tree[1 .. $#$tree]
    if $type eq 'root';

  # DOCTYPE
  return '[1] . '>' if $type eq 'doctype';

  # Comment
  return '' if $type eq 'comment';

  # CDATA
  return '[1] . ']]>' if $type eq 'cdata';

  # Processing instruction
  return '[1] . '?>' if $type eq 'pi';

  # Everything else
  return '';
}

sub _start {
  my ($start, $attrs, $xml, $current) = @_;

  # Autoclose optional HTML elements
  if (!$xml && $$current->[0] ne 'root') {
    if (my $end = $END{$start}) { _end($end, 0, $current) }

    elsif (my $close = $CLOSE{$start}) {
      my ($allowed, $scope) = @$close;

      # Close allowed parent elements in scope
      my $parent = $$current;
      while ($parent->[0] ne 'root' && !$scope->{$parent->[1]}) {
        _end($parent->[1], 0, $current) if $allowed->{$parent->[1]};
        $parent = $parent->[3];
      }
    }
  }

  # New tag
  push @$$current, my $new = ['tag', $start, $attrs, $$current];
  weaken $new->[3];
  $$current = $new;
}

sub _tag {
  my $tree = ['tag', shift, undef, undef];

  # Content
  push @$tree, ref $_[-1] eq 'CODE' ? ['raw', pop->()] : ['text', pop]
    if @_ % 2;

  # Attributes
  my $attrs = $tree->[2] = {@_};
  return $tree unless exists $attrs->{data} && ref $attrs->{data} eq 'HASH';
  my $data = delete $attrs->{data};
  @$attrs{map { y/_/-/; lc "data-$_" } keys %$data} = values %$data;

  return $tree;
}

1;

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