Message/DOM/Document.pm

## NOTE: This module will be renamed as Document.pm.

package Message::DOM::Document;
use strict;
our $VERSION=do{my @r=(q$Revision: 1.21 $=~/\d+/g);sprintf "%d."."%02d" x $#r,@r};
push our @ISA, 'Message::DOM::Node', 'Message::IF::Document',
    'Message::IF::DocumentTraversal', 'Message::IF::DocumentXDoctype',
    'Message::IF::DocumentSelector', # MUST in Selectors API spec
    'Message::IF::HTMLDocument';
require Message::DOM::Node;
use Char::Class::XML
    qw/
      InXML_NameStartChar10 InXMLNameStartChar11
      InXMLNameChar10 InXMLNameChar11
      InXML_NCNameStartChar10 InXMLNCNameStartChar11
      InXMLNCNameChar10 InXMLNCNameChar11
    /;

sub ____new ($$) {
  my $self = shift->SUPER::____new (undef);
  $$self->{implementation} = $_[0];
  $$self->{strict_error_checking} = 1;
  $$self->{child_nodes} = [];
  $$self->{'http://suika.fam.cx/www/2006/dom-config/strict-document-children'} = 1;
  $$self->{'http://suika.fam.cx/www/2006/dom-config/dtd-default-attribute'} = 1;
  $$self->{'http://suika.fam.cx/www/2006/dom-config/clone-entity-reference-subtree'} = 1;
  $$self->{'error-handler'} = sub ($) {
    ## NOTE: Same as one set by |setParameter| with |undef| value.
    warn $_[0];
    return $_[0]->severity != 3; # SEVERITY_FATAL_ERROR
  };
  return $self;
} # ____new
             
sub AUTOLOAD {
  my $method_name = our $AUTOLOAD;
  $method_name =~ s/.*:://;
  return if $method_name eq 'DESTROY';

  if ({
    ## Read-only attributes (trivial accessors)
    implementation => 1,
  }->{$method_name}) {
    no strict 'refs';
    eval qq{
      sub $method_name (\$) {
        return \${\$_[0]}->{$method_name}; 
      }
    };
    goto &{ $AUTOLOAD };
  } elsif ({
    ## Read-write attributes (DOMString, trivial accessors)
    document_uri => 1,
    input_encoding => 1,
  }->{$method_name}) {
    no strict 'refs';
    eval qq{
      sub $method_name (\$;\$) {
        if (\@_ > 1) {
          if (\${\$_[0]}->{strict_error_checking} and
              \${\$_[0]}->{manakai_read_only}) {
            report Message::DOM::DOMException
                -object => \$_[0],
                -type => 'NO_MODIFICATION_ALLOWED_ERR',
                -subtype => 'READ_ONLY_NODE_ERR';
          }
          if (defined \$_[1]) {
            \${\$_[0]}->{$method_name} = ''.\$_[1];
          } else {
            delete \${\$_[0]}->{$method_name};
          }
        }
        return \${\$_[0]}->{$method_name};
      }
    };
    goto &{ $AUTOLOAD };
  } elsif ({
    ## Read-write attributes (boolean, trivial accessors)
    all_declarations_processed => 1,
  }->{$method_name}) {
    no strict 'refs';
    eval qq{
      sub $method_name (\$;\$) {
        if (\@_ > 1) {
          if (\${\$_[0]}->{manakai_strict_error_checking} and
              \${\$_[0]}->{manakai_read_only}) {
            report Message::DOM::DOMException
                -object => \$_[0],
                -type => 'NO_MODIFICATION_ALLOWED_ERR',
                -subtype => 'READ_ONLY_NODE_ERR';
          }
          if (\$_[1]) {
            \${\$_[0]}->{$method_name} = 1;
          } else {
            delete \${\$_[0]}->{$method_name};
          }
        }
        return \${\$_[0]}->{$method_name};
      }
    };
    goto &{ $AUTOLOAD };
  } elsif (my $module_name = {
    create_attribute => 'Message::DOM::Attr',
    create_attribute_ns => 'Message::DOM::Attr',
    create_attribute_definition => 'Message::DOM::AttributeDefinition',
    create_cdata_section => 'Message::DOM::Text',
    create_comment => 'Message::DOM::CharacterData',
    create_document_fragment => 'Message::DOM::DocumentFragment',
    create_document_type_definition => 'Message::DOM::DocumentType',
    create_element => 'Message::DOM::Element',
    create_element_ns => 'Message::DOM::Element',
    create_element_type_definition => 'Message::DOM::ElementTypeDefinition',
    create_entity_reference => 'Message::DOM::EntityReference',
    create_general_entity => 'Message::DOM::Entity',
    create_notation => 'Message::DOM::Notation',
    create_processing_instruction => 'Message::DOM::ProcessingInstruction',
    manakai_create_serial_walker => 'Message::DOM::SerialWalker',
    create_text_node => 'Message::DOM::Text',
    create_tree_walker => 'Message::DOM::TreeWalker',
    query_selector => 'Message::DOM::SelectorsAPI',
    query_selector_all => 'Message::DOM::SelectorsAPI',
  }->{$method_name}) {
    eval qq{ require $module_name } or die $@;
    goto &{ $AUTOLOAD };
  } else {
    require Carp;
    Carp::croak (qq<Can't locate method "$AUTOLOAD">);
  }
} # AUTOLOAD
sub implementation ($);
sub create_attribute ($$);
sub create_attribute_ns ($$$);
sub create_attribute_definition ($$);
sub create_cdata_section ($$);
sub create_comment ($$);
sub create_document_fragment ($);
sub create_document_type_definition ($$);
sub create_element ($$);
sub create_element_ns ($$$);
sub create_element_type_definition ($$);
sub create_entity_reference ($$);
sub create_general_entity ($$);
sub create_notation ($$);
sub create_processing_instruction ($$$);
sub create_text_node ($$);

## |Node| attributes

sub base_uri ($) {
  my $v = ${$_[0]}->{manakai_entity_base_uri};
  if (defined $v) {
    return $v;
  } else {
    return ${$_[0]}->{document_uri};
  }
  ## TODO: HTML5 <base>
} # base_uri

sub node_name () { '#document' }

sub node_type () { 9 } # DOCUMENT_NODE

sub text_content ($;$) {
  my $self = shift;
  if ($$self->{'http://suika.fam.cx/www/2006/dom-config/strict-document-children'}) {
    return undef;
  } else {
    local $Error::Depth = $Error::Depth + 1;
    return $self->SUPER::text_content (@_);
  }
} # text_content

## |Node| methods

sub adopt_node ($$) {
  my ($self, $source) = @_;
  ## TODO: Should we apply |copy-asis| configuration parameter to this method?

  return undef unless UNIVERSAL::isa ($source, 'Message::DOM::Node');

  my $strict = $self->strict_error_checking;
  if ($strict and $$self->{manakai_read_only}) {
    report Message::DOM::DOMException
        -object => $self,
        -type => 'NO_MODIFICATION_ALLOWED_ERR',
        -subtype => 'READ_ONLY_NODE_ERR';
  }

  my $parent = $source->parent_node;
  if ($strict and defined $parent and $$parent->{manakai_read_only}) {
    report Message::DOM::DOMException
        -object => $self,
        -type => 'NO_MODIFICATION_ALLOWED_ERR',
        -subtype => 'READ_ONLY_NODE_ERR';
  }

  my $nt = $source->node_type;
  my $oe;
  if ($nt == 2) { # ATTRIBUTE_NODE
    $oe = $source->owner_element;
    if ($strict and defined $oe and $$oe->{manakai_read_only}) {
      report Message::DOM::DOMException
          -object => $self,
          -type => 'NO_MODIFICATION_ALLOWED_ERR',
          -subtype => 'READ_ONLY_NODE_ERR';
    }
  } elsif ($nt == 9 or $nt == 10 or $nt == 6 or $nt == 12 or
           $nt == 81001 or $nt == 81002) {
    # DOCUMENT_NODE, DOCUMENT_TYPE_NODE, ENTITY_NODE, NOTATION_NODE,
    # ELEMENT_TYPE_DEFINITION_NODE, ATTRIBUTE_DEFINITION_NODE
    report Message::DOM::DOMException
        -object => $self,
        -type => 'NOT_SUPPORTED_ERR',
        -subtype => 'ADOPT_NODE_TYPE_NOT_SUPPORTED_ERR';
    ## ISSUE: Define ELEMENT_TYPE_DEFINITION_NODE and ATTRIBUTE_DEFINITION_NODE
  }

  my @change_od;
  my @nodes = ($source);
  while (@nodes) {
    my $node = shift @nodes;
    my $nt = $node->node_type;
    if ($strict and $$node->{manakai_read_only}) {
      report Message::DOM::DOMException
          -object => $self,
          -type => 'NO_MODIFICATION_ALLOWED_ERR',
          -subtype => 'READ_ONLY_NODE_ERR';
    }

    push @change_od, $node;
    push @nodes, @{$node->child_nodes}, @{$node->attributes or []};
  } # @nodes

  local $Error::Depth = $Error::Depth + 1;

  if (defined $parent) {
    $parent->remove_child ($source);
  } elsif (defined $oe) {
    $oe->remove_attribute_node ($source);
  }

  return $source if $self eq $change_od[0]->owner_document;
                         ## NOTE: The array must have more than zero
                         ##       nodes by definition.  In addition,
                         ##       it cannot contain document or document
                         ##       type nodes in current implementation.

  my @ud_node;
  for my $n (@change_od) {
    $$n->{owner_document} = $self;
    Scalar::Util::weaken ($$n->{owner_document});
    if ($$n->{user_data}) {
      push @ud_node, $n;
    }
  }

  for my $src (@ud_node) {
    my $src_ud = $$src->{user_data};
    for my $key (keys %{$src_ud}) {
      my $dh = $src_ud->{$key}->[1];
      if ($dh) {
        $dh->(5, $key, $src_ud->{$key}->[0], $src, undef); # NODE_ADOPTED
      }
    }
  }

  return $source;
} # adopt_node

sub append_child ($$) {
  ## NOTE: Overrides |Node|'s implementation.
  my $self = $_[0];
  
  ## NOTE: |$self_od| code here in some $self->node_type.

  ## -- Node Type check
  my @new_child;
  my $new_child_parent;
  if ($_[1]->node_type == 11) { # DOCUMENT_FRAGMENT_NODE
    push @new_child, @{$_[1]->child_nodes};
    $new_child_parent = $_[1];
  } else {
    @new_child = ($_[1]);
    $new_child_parent = $_[1]->parent_node;
  }

  ## NOTE: Depends on $self->node_type:
  if ($$self->{strict_error_checking}) {
    my $child_od = $_[1]->owner_document || $_[1]; # might be DocumentType
    if ($self ne $child_od and $child_od->node_type != 10) {
      report Message::DOM::DOMException # DOCUMENT_TYPE_NODE
          -object => $self,
          -type => 'WRONG_DOCUMENT_ERR',
          -subtype => 'EXTERNAL_OBJECT_ERR';
    }

    if ($$self->{manakai_read_only} or
        (@new_child and defined $new_child_parent and
         $$new_child_parent->{manakai_read_only})) {
      report Message::DOM::DOMException
          -object => $self,
          -type => 'NO_MODIFICATION_ALLOWED_ERR',
          -subtype => 'READ_ONLY_NODE_ERR';
    }

    ## NOTE: Only in |Document|:
    my $strict_children = $self->dom_config->get_parameter
        (q<http://suika.fam.cx/www/2006/dom-config/strict-document-children>);
    if ($strict_children) {
      my $has_el;
      my $has_dt;
      my $child_nt = $_[1]->node_type;
      if ($child_nt == 1) { # ELEMENT_NODE
        $has_el = 1;
      } elsif ($child_nt == 10) { # DOCUMENT_TYPE_NODE
        $has_dt = 1;
      } elsif ($child_nt == 11) { # DOCUMENT_FRAGMENT_NODE
        for my $cn (@{$_[1]->child_nodes}) {
          my $cnt = $cn->node_type;
          if ($cnt == 1) { # ELEMENT_NODE
            if ($has_el) {
              report Message::DOM::DOMException
                  -object => $self,
                  -type => 'HIERARCHY_REQUEST_ERR',
                  -subtype => 'CHILD_NODE_TYPE_ERR';
            }
            $has_el = 1;
          } elsif ($cnt == 10) { # DOCUMENT_TYPE_NODE
            ## NOTE: |DocumentType| node cannot be contained in
            ## |DocumentFragment| in strict mode.
            if ($has_dt) {
              report Message::DOM::DOMException
                  -object => $self,
                  -type => 'HIERARCHY_REQUEST_ERR',
                  -subtype => 'CHILD_NODE_TYPE_ERR';
            }
            $has_dt = 1;
          }
        }
      }
  
      if ($has_el) {
        my $anode = $self->last_child;
        while (defined $anode) {
          if ($anode->node_type == 1) { # ELEMENT_NODE
            report Message::DOM::DOMException
                -object => $self,
                -type => 'HIERARCHY_REQUEST_ERR',
                -subtype => 'CHILD_NODE_TYPE_ERR';
          }
          $anode = $anode->previous_sibling;
        }
      } # has_el
      if ($has_dt) {
        my $anode = $self->last_child;
        while (defined $anode) {
          my $ant = $anode->node_type;
          if ($ant == 1 or $ant == 10) { # ELEMENT_NODE or DOCUMENT_TYPE_NODE
            report Message::DOM::DOMException
                -object => $self,
                -type => 'HIERARCHY_REQUEST_ERR',
                -subtype => 'CHILD_NODE_TYPE_ERR';
          }
          $anode = $anode->previous_sibling;
        }
      } # has_dt
    }

    for my $cn (@new_child) {
      unless ({
               3, (not $strict_children), # TEXT_NODE
               5, (not $strict_children), # ENTITY_REFERENCE_NODE
               1, 1, # ELEMENT_NODE
               4, (not $strict_children), # CDATA_SECTION_NODE
               7, 1, # PROCESSING_INSTRUCTION_NODE
               8, 1, # COMMENT_NODE
               10, 1, # DOCUMENT_TYPE_NODE
              }->{$cn->node_type}) {
        report Message::DOM::DOMException
            -object => $self,
            -type => 'HIERARCHY_REQUEST_ERR',
            -subtype => 'CHILD_NODE_TYPE_ERR';
      }
    }

    ## NOTE: Ancestor check here in |Node|.
  }

  ## NOTE: "Insert at" code only in insert_before and replace_child

  ## -- Removes from parent
  if ($new_child_parent) {
    if (@new_child == 1) {
      my $v = $$new_child_parent->{child_nodes};
      RP: for my $i (0..$#$v) {
        if ($v->[$i] eq $new_child[0]) {
          splice @$v, $i, 1, ();
          last RP;
        }
      } # RP
    } else {
      @{$$new_child_parent->{child_nodes}} = ();
    }
  }

  ## -- Rewrite the |parentNode| properties
  for my $nc (@new_child) {
    $$nc->{parent_node} = $self;
    Scalar::Util::weaken ($$nc->{parent_node});
  }

  ## NOTE: Depends on method:
  push @{$$self->{child_nodes}}, @new_child;

  ## NOTE: Only in |Document|.
  for (@new_child) {
    delete $$_->{implementation};
    $$_->{owner_document} = $self;
    Scalar::Util::weaken ($$_->{owner_document});
  }

  return $_[1];
} # apepnd_child

sub manakai_append_text ($$) {
  my $self = shift;
  if ($$self->{'http://suika.fam.cx/www/2006/dom-config/strict-document-children'}) {
    #
  } else {
    local $Error::Depth = $Error::Depth + 1;
    return $self->SUPER::manakai_append_text (@_);
  }
} # manakai_append_text

sub insert_before ($$) {
  ## NOTE: Overrides |Node|'s implementation.
  my $self = $_[0];

  ## NOTE: |$self_od| code here depending on $self->node_type.

  ## -- Node Type check
  my @new_child;
  my $new_child_parent;
  if ($_[1]->node_type == 11) { # DOCUMENT_FRAGMENT_NODE
    push @new_child, @{$_[1]->child_nodes};
    $new_child_parent = $_[1];
  } else {
    @new_child = ($_[1]);
    $new_child_parent = $_[1]->parent_node;
  }

  ## NOTE: Depends on $self->node_type:
  if ($$self->{strict_error_checking}) {
    my $child_od = $_[1]->owner_document || $_[1]; # might be DocumentType
    if ($self ne $child_od and $child_od->node_type != 10) {
      report Message::DOM::DOMException # DOCUMENT_TYPE_NODE
          -object => $self,
          -type => 'WRONG_DOCUMENT_ERR',
          -subtype => 'EXTERNAL_OBJECT_ERR';
    }

    if ($$self->{manakai_read_only} or
        (@new_child and defined $new_child_parent and
         $$new_child_parent->{manakai_read_only})) {
      report Message::DOM::DOMException
          -object => $self,
          -type => 'NO_MODIFICATION_ALLOWED_ERR',
          -subtype => 'READ_ONLY_NODE_ERR';
    }

    ## NOTE: Only in |Document|:
    my $strict_children = $self->dom_config->get_parameter
        (q<http://suika.fam.cx/www/2006/dom-config/strict-document-children>);
    if ($strict_children) {
      my $has_el;
      my $has_dt;
      my $child_nt = $_[1]->node_type;
      if ($child_nt == 1) { # ELEMENT_NODE
        $has_el = 1;
      } elsif ($child_nt == 10) { # DOCUMENT_TYPE_NODE
        $has_dt = 1;
      } elsif ($child_nt == 11) { # DOCUMENT_FRAGMENT_NODE
        for my $cn (@{$_[1]->child_nodes}) {
          my $cnt = $cn->node_type;
          if ($cnt == 1) { # ELEMENT_NODE
            if ($has_el) {
              report Message::DOM::DOMException
                  -object => $self,
                  -type => 'HIERARCHY_REQUEST_ERR',
                  -subtype => 'CHILD_NODE_TYPE_ERR';
            }
            $has_el = 1;
          } elsif ($cnt == 10) { # DOCUMENT_TYPE_NODE
            ## NOTE: |DocumentType| node cannot be contained in
            ## |DocumentFragment| in strict mode.
            if ($has_dt) {
              report Message::DOM::DOMException
                  -object => $self,
                  -type => 'HIERARCHY_REQUEST_ERR',
                  -subtype => 'CHILD_NODE_TYPE_ERR';
            }
            $has_dt = 1;
          }
        }
      }

      ## ISSUE: This code is wrong.  Old manakai's implementation
      ## is better, but it is also wrong in some edge cases.
      ## Maybe we should remove these code entirely.  DOM3Core
      ## conformance is not important for this bit.  It only makes
      ## things too complex.  Same for replace_child's code.
      if ($has_el) {
        my $anode = $self->last_child;
        while (defined $anode) {
          if ($anode->node_type == 1) { # ELEMENT_NODE
            report Message::DOM::DOMException
                -object => $self,
                -type => 'HIERARCHY_REQUEST_ERR',
                -subtype => 'CHILD_NODE_TYPE_ERR';
          }
          $anode = $anode->previous_sibling;
        }
      } # has_el
      if ($has_dt) {
        my $anode = $self->last_child;
        while (defined $anode) {
          my $ant = $anode->node_type;
          if ($ant == 1 or $ant == 10) { # ELEMENT_NODE or DOCUMENT_TYPE_NODE
            report Message::DOM::DOMException
                -object => $self,
                -type => 'HIERARCHY_REQUEST_ERR',
                -subtype => 'CHILD_NODE_TYPE_ERR';
          }
          $anode = $anode->previous_sibling;
        }
      } # has_dt
    }

    for my $cn (@new_child) {
      unless ({
               3, (not $strict_children), # TEXT_NODE
               5, (not $strict_children), # ENTITY_REFERENCE_NODE
               1, 1, # ELEMENT_NODE
               4, (not $strict_children), # CDATA_SECTION_NODE
               7, 1, # PROCESSING_INSTRUCTION_NODE
               8, 1, # COMMENT_NODE
               10, 1, # DOCUMENT_TYPE_NODE
              }->{$cn->node_type}) {
        report Message::DOM::DOMException
            -object => $self,
            -type => 'HIERARCHY_REQUEST_ERR',
            -subtype => 'CHILD_NODE_TYPE_ERR';
      }
    }

    ## NOTE: Ancestor check here in |Node|.
  }
  
  ## -- Insert at... ## NOTE: Only in insert_before and replace_child
  my $index = -1; # last
  if (defined $_[2]) {
    ## error if $_[1] eq $_[2];
    
    my $cns = $self->child_nodes;
    my $cnsl = @$cns;
    C: {
      $index = 0;
      for my $i (0..($cnsl-1)) {
        my $cn = $cns->[$i];
        if ($cn eq $_[2]) {
          $index += $i;
          last C;
        } elsif ($cn eq $_[1]) {
          $index = -1; # offset
        }
      }
      
      report Message::DOM::DOMException
          -object => $self,
          -type => 'NOT_FOUND_ERR',
          -subtype => 'NOT_CHILD_ERR';
    } # C
  }
  ## NOTE: "else" only in replace_child

  ## -- Removes from parent
  if ($new_child_parent) {
    if (@new_child == 1) {
      my $v = $$new_child_parent->{child_nodes};
      RP: for my $i (0..$#$v) {
        if ($v->[$i] eq $new_child[0]) {
          splice @$v, $i, 1, ();
          last RP;
        }
      } # RP
    } else {
      @{$$new_child_parent->{child_nodes}} = ();
    }
  }

  ## -- Rewrite the |parentNode| properties
  for my $nc (@new_child) {
    $$nc->{parent_node} = $self;
    Scalar::Util::weaken ($$nc->{parent_node});
  }

  ## NOTE: Depends on method:
  if ($index == -1) {
    push @{$$self->{child_nodes}}, @new_child;
  } else {
    splice @{$$self->{child_nodes}}, $index, 0, @new_child;
  }

  ## NOTE: Only in |Document|.
  for (@new_child) {
    delete $$_->{implementation};
    $$_->{owner_document} = $self;
    Scalar::Util::weaken ($$_->{owner_document});
  }

  return $_[1];
} # insert_before

sub replace_child ($$) {
  ## NOTE: Overrides |Node|'s implementation.
  my $self = $_[0];

  ## NOTE: |$self_od| code here depending on $self->node_type.

  ## -- Node Type check
  my @new_child;
  my $new_child_parent;
  if ($_[1]->node_type == 11) { # DOCUMENT_FRAGMENT_NODE
    push @new_child, @{$_[1]->child_nodes};
    $new_child_parent = $_[1];
  } else {
    @new_child = ($_[1]);
    $new_child_parent = $_[1]->parent_node;
  }

  ## NOTE: Depends on $self->node_type:
  if ($$self->{strict_error_checking}) {
    my $child_od = $_[1]->owner_document || $_[1]; # might be DocumentType
    if ($self ne $child_od and $child_od->node_type != 10) {
      report Message::DOM::DOMException # DOCUMENT_TYPE_NODE
          -object => $self,
          -type => 'WRONG_DOCUMENT_ERR',
          -subtype => 'EXTERNAL_OBJECT_ERR';
    }

    if ($$self->{manakai_read_only} or
        (@new_child and defined $new_child_parent and
         $$new_child_parent->{manakai_read_only})) {
      report Message::DOM::DOMException
          -object => $self,
          -type => 'NO_MODIFICATION_ALLOWED_ERR',
          -subtype => 'READ_ONLY_NODE_ERR';
    }

    ## NOTE: Only in |Document|:
    my $strict_children = $self->dom_config->get_parameter
        (q<http://suika.fam.cx/www/2006/dom-config/strict-document-children>);
    if ($strict_children) {
      my $has_el;
      my $has_dt;
      my $child_nt = $_[1]->node_type;
      if ($child_nt == 1) { # ELEMENT_NODE
        $has_el = 1;
      } elsif ($child_nt == 10) { # DOCUMENT_TYPE_NODE
        $has_dt = 1;
      } elsif ($child_nt == 11) { # DOCUMENT_FRAGMENT_NODE
        for my $cn (@{$_[1]->child_nodes}) {
          my $cnt = $cn->node_type;
          if ($cnt == 1) { # ELEMENT_NODE
            if ($has_el) {
              report Message::DOM::DOMException
                  -object => $self,
                  -type => 'HIERARCHY_REQUEST_ERR',
                  -subtype => 'CHILD_NODE_TYPE_ERR';
            }
            $has_el = 1;
          } elsif ($cnt == 10) { # DOCUMENT_TYPE_NODE
            ## NOTE: |DocumentType| node cannot be contained in
            ## |DocumentFragment| in strict mode.
            if ($has_dt) {
              report Message::DOM::DOMException
                  -object => $self,
                  -type => 'HIERARCHY_REQUEST_ERR',
                  -subtype => 'CHILD_NODE_TYPE_ERR';
            }
            $has_dt = 1;
          }
        }
      }
  
      if ($has_el) {
        my $anode = $self->last_child;
        while (defined $anode) {
          if ($anode->node_type == 1) { # ELEMENT_NODE
            report Message::DOM::DOMException
                -object => $self,
                -type => 'HIERARCHY_REQUEST_ERR',
                -subtype => 'CHILD_NODE_TYPE_ERR';
          }
          $anode = $anode->previous_sibling;
        }
      } # has_el
      if ($has_dt) {
        my $anode = $self->last_child;
        while (defined $anode) {
          my $ant = $anode->node_type;
          if ($ant == 1 or $ant == 10) { # ELEMENT_NODE or DOCUMENT_TYPE_NODE
            report Message::DOM::DOMException
                -object => $self,
                -type => 'HIERARCHY_REQUEST_ERR',
                -subtype => 'CHILD_NODE_TYPE_ERR';
          }
          $anode = $anode->previous_sibling;
        }
      } # has_dt
    }

    for my $cn (@new_child) {
      unless ({
               3, (not $strict_children), # TEXT_NODE
               5, (not $strict_children), # ENTITY_REFERENCE_NODE
               1, 1, # ELEMENT_NODE
               4, (not $strict_children), # CDATA_SECTION_NODE
               7, 1, # PROCESSING_INSTRUCTION_NODE
               8, 1, # COMMENT_NODE
               10, 1, # DOCUMENT_TYPE_NODE
              }->{$cn->node_type}) {
        report Message::DOM::DOMException
            -object => $self,
            -type => 'HIERARCHY_REQUEST_ERR',
            -subtype => 'CHILD_NODE_TYPE_ERR';
      }
    }

    ## NOTE: Ancestor check here in |Node|.
  }
  
  ## -- Insert at... ## NOTE: Only in insertBefore and replaceChild
  my $index = -1; # last
  if (defined $_[2]) {
    ## error if $_[1] eq $_[2];
    
    my $cns = $self->child_nodes;
    my $cnsl = @$cns;
    C: {
      $index = 0;
      for my $i (0..($cnsl-1)) {
        my $cn = $cns->[$i];
        if ($cn eq $_[2]) {
          $index += $i;
          last C;
        } elsif ($cn eq $_[1]) {
          $index = -1; # offset
        }
      }
      
      report Message::DOM::DOMException
          -object => $self,
          -type => 'NOT_FOUND_ERR',
          -subtype => 'NOT_CHILD_ERR';
    } # C
  } else {
    ## NOTE: Only in replaceChild
    report Message::DOM::DOMException
        -object => $self,
        -type => 'NOT_FOUND_ERR',
        -subtype => 'NOT_CHILD_ERR';
  }

  ## -- Removes from parent
  if ($new_child_parent) {
    if (@new_child == 1) {
      my $v = $$new_child_parent->{child_nodes};
      RP: for my $i (0..$#$v) {
        if ($v->[$i] eq $new_child[0]) {
          splice @$v, $i, 1, ();
          last RP;
        }
      } # RP
    } else {
      @{$$new_child_parent->{child_nodes}} = ();
    }
  }

  ## -- Rewrite the |parentNode| properties
  for my $nc (@new_child) {
    $$nc->{parent_node} = $self;
    Scalar::Util::weaken ($$nc->{parent_node});
  }

  ## NOTE: Depends on method:
  splice @{$$self->{child_nodes}}, $index, 1, @new_child;
  delete ${$_[2]}->{parent_node};

  ## NOTE: Only in |Document|.
  for (@new_child) {
    delete $$_->{implementation};
    $$_->{owner_document} = $self;
    Scalar::Util::weaken ($$_->{owner_document});
  }

  return $_[2];
} # replace_child

## |Document| attributes

## NOTE: A manakai extension.
sub all_declarations_processed ($;$);

sub doctype ($) {
  my $self = $_[0];
  for (@{$self->child_nodes}) {
    if ($_->node_type == 10) { # DOCUMENT_TYPE_NODE
      return $_;
    }
  }
  return undef;
} # doctype

sub document_element ($) {
  my $self = shift;
  for (@{$self->child_nodes}) {
    if ($_->node_type == 1) { # ELEMENT_NODE
      return $_;
    }
  }
  return undef;
} # document_element

sub document_uri ($;$);

sub dom_config ($) {
  require Message::DOM::DOMConfiguration;
  return bless \\($_[0]), 'Message::DOM::DOMConfiguration';
} # dom_config

sub manakai_entity_base_uri ($;$) {
  my $self = $_[0];
  if (@_ > 1) {
    if ($$self->{strict_error_checking}) {
      if ($$self->{manakai_read_only}) {
        report Message::DOM::DOMException
            -object => $self,
            -type => 'NO_MODIFICATION_ALLOWED_ERR',
            -subtype => 'READ_ONLY_NODE_ERR';
      }
    }
    if (defined $_[1]) {
      $$self->{manakai_entity_base_uri} = ''.$_[1];
    } else {
      delete $$self->{manakai_entity_base_uri};
    }
  }
  
  if (defined $$self->{manakai_entity_base_uri}) {
    return $$self->{manakai_entity_base_uri};
  } else {
    return $$self->{document_uri};
  }
} # manakai_entity_base_uri

sub input_encoding ($;$);

sub strict_error_checking ($;$) {
  ## NOTE: Same as trivial boolean accessor, except no read-only checking.
  if (@_ > 1) {
    if ($_[1]) {
      ${$_[0]}->{strict_error_checking} = 1;
    } else {
      delete ${$_[0]}->{strict_error_checking};
    }
  }                   
  return ${$_[0]}->{strict_error_checking};
} # strict_error_checking

## ISSUE: Setting manakai_is_html true shadows 
## xml_* properties.  Is this desired?

sub xml_encoding ($;$) {
  my $self = $_[0];
  if (@_ > 1) {
    ## NOTE: A manakai extension.
    if ($$self->{strict_error_checking}) {
      if ($$self->{manakai_is_html}) {
        report Message::DOM::DOMException
            -object => $self,
            -type => 'NOT_SUPPORTED_ERR',
            -subtype => 'NON_HTML_OPERATION_ERR';
      }
      if ($$self->{manakai_read_only}) {
        report Message::DOM::DOMException
            -object => $self,
            -type => 'NO_MODIFICATION_ALLOWED_ERR',
            -subtype => 'READ_ONLY_NODE_ERR';
      }
    }
    if (defined $_[1]) {
      $$self->{xml_encoding} = ''.$_[1];
    } else {
      delete $$self->{xml_encoding};
    }
  }
  
  if ($$self->{manakai_is_html}) {
    return undef;
  } else {
    return $$self->{xml_encoding};
  }
} # xml_encoding

sub xml_standalone ($;$) {
  my $self = $_[0];
  if (@_ > 1) {
    if ($$self->{strict_error_checking}) {
      if ($$self->{manakai_is_html}) {
        report Message::DOM::DOMException
            -object => $self,
            -type => 'NOT_SUPPORTED_ERR',
            -subtype => 'NON_HTML_OPERATION_ERR';
      }
      ## NOTE: Not in DOM3.
      if ($$self->{manakai_read_only}) {
        report Message::DOM::DOMException
            -object => $self,
            -type => 'NO_MODIFICATION_ALLOWED_ERR',
            -subtype => 'READ_ONLY_NODE_ERR';
      }
    }
    if ($_[1]) {
      $$self->{xml_standalone} = 1;
    } else {
      delete $$self->{xml_standalone};
    }
  }
  
  if ($$self->{manakai_is_html}) {
    return 0;
  } else {
    return $$self->{xml_standalone};
  }
} # xml_standalone

sub xml_version ($;$) {
  my $self = $_[0];
  if (@_ > 1) {
    my $v = ''.$_[1];
    if ($$self->{strict_error_checking}) {
      if ($$self->{manakai_is_html}) {
        report Message::DOM::DOMException
            -object => $self,
            -type => 'NOT_SUPPORTED_ERR',
            -subtype => 'NON_HTML_OPERATION_ERR';
      }
      if ($v ne '1.0' and $v ne '1.1') {
        report Message::DOM::DOMException
            -object => $self,
            -type => 'NOT_SUPPORTED_ERR',
            -subtype => 'UNKNOWN_XML_VERSION_ERR';
      }
      if ($$self->{manakai_read_only}) {
        ## ISSUE: Not in DOM3.
        report Message::DOM::DOMException
            -object => $self,
            -type => 'NO_MODIFICATION_ALLOWED_ERR',
            -subtype => 'READ_ONLY_NODE_ERR';
      }
    }
    $$self->{xml_version} = $v;
  }
  
  if (defined wantarray) {
    if ($$self->{manakai_is_html}) {
      return undef;
    } elsif (defined $$self->{xml_version}) {
      return $$self->{xml_version};
    } else {
      return '1.0';
    }
  }
} # xml_version

## |Document| methods

sub get_element_by_id ($$) {
  local $Error::Depth = $Error::Depth + 1;
  my @nodes = @{$_[0]->child_nodes};
  N: while (@nodes) {
    my $node = shift @nodes;
    next N unless $node->node_type == 1; # ELEMENT_NODE
    for my $attr (@{$node->attributes}) {
      if ($attr->is_id and $attr->value eq $_[1]) {
        return $node;
      }
    }
    unshift @nodes, @{$node->child_nodes};
  } # N
  return undef;
} # get_element_by_id

## TODO: HTML5 case normalization
sub get_elements_by_tag_name ($$) {
  my $name = ''.$_[1];
  my $chk;
  if ($name eq '*') {
    $chk = sub () { 1 };
  } else {
    $chk = sub ($) {
      return $_[0]->manakai_tag_name eq $name;
    };
  }

  require Message::DOM::NodeList;
  return bless \[$_[0], $chk], 'Message::DOM::NodeList::GetElementsList';
} # get_elements_by_tag_name

sub get_elements_by_tag_name_ns ($$$) {
  my $nsuri = defined $_[1] ? ''.$_[1] : '';
  my $lname = ''.$_[2];
  my $chk;
  if ($nsuri eq '*') {
    if ($lname eq '*') {
      $chk = sub () { 1 };
    } else {
      $chk = sub ($) {
        return $_[0]->manakai_local_name eq $lname;
      };
    }
  } elsif ($nsuri eq '') {
    if ($lname eq '*') {
      $chk = sub ($) {
        return not defined $_[0]->namespace_uri;
      };
    } else {
      $chk = sub ($) {
        return (not defined $_[0]->namespace_uri and
                $_[0]->manakai_local_name eq $lname);
      };
    }
  } else {
    if ($lname eq '*') {
      $chk = sub ($) {
        my $ns = $_[0]->namespace_uri;
        return (defined $ns and $ns eq $nsuri);
      };
    } else {
      $chk = sub ($) {
        my $ns = $_[0]->namespace_uri;
        return (defined $ns and $ns eq $nsuri and
                $_[0]->manakai_local_name eq $lname);
      };
    }
  }

  require Message::DOM::NodeList;
  return bless \[$_[0], $chk], 'Message::DOM::NodeList::GetElementsList';
} # get_elements_by_tag_name

## TODO: import_node

## TODO: normalize_document

## TODO: rename_node

## |DocumentTraversal| methods

## TODO: create_node_iterator

sub manakai_create_serial_walker ($$;$$$);

sub create_tree_walker ($$;$$$);

## |HTMLDocument| attributes

sub compat_mode ($) {
  if (${$_[0]}->{manakai_is_html}) {
    if (defined ${$_[0]}->{manakai_compat_mode} and
        ${$_[0]}->{manakai_compat_mode} eq 'quirks') {
      return 'BackCompat';
    }
  }
  return 'CSS1Compat';
} # compat_mode

sub manakai_compat_mode ($;$) {
  if (${$_[0]}->{manakai_is_html}) {
    if (@_ > 1 and defined $_[1] and
        {'no quirks' => 1, 'limited quirks' => 1, 'quirks' => 1}->{$_[1]}) {
      ${$_[0]}->{manakai_compat_mode} = $_[1];
    }
    return ${$_[0]}->{manakai_compat_mode} || 'no quirks';
  } else {
    return 'no quirks';
  }
} # manakai_compat_mode

sub inner_html ($;$) {
  my $self = $_[0];
  local $Error::Depth = $Error::Depth + 1;

  if ($$self->{manakai_is_html}) {
    require Whatpm::HTML;
    if (@_ > 1) {
      ## Step 1
      ## TODO: Stop parsing and ...
      
      ## Step 2
      my @cn = @{$self->child_nodes};
      for (@cn) { ## NOTE: Might throw a |NO_MODIFICATION_ALLOWED_ERR|.
        $self->remove_child ($_); #
      }

      ## Step 3, 4, 5
      Whatpm::HTML->parse_string ($_[1] => $self);

      ## TODO:
      ## <script>var input = function_to_do_xmlhttprequest (location.href);
      ## document.innerHTML = input</script>

      return unless defined wantarray;
    }

    return ${ Whatpm::HTML->get_inner_html ($self) };
  } else {
    if (@_ > 1) {
      ## Step 1
      require Whatpm::XMLParser; # MUST
      my $doc = $self->implementation->create_document;
      
      ## Step 2
      #

      ## Step 3
      $doc = Whatpm::XMLParser->parse_string ($_[1] => $doc); # MUST

      ## Step 4
      #

      ## Step 5
      ## TODO: ill-formed -> SYNTAX_ERR # MUST

      ## Step 6 # MUST
      my @cn = @{$self->child_nodes}; ## TODO: If read-only
      for (@cn) {
        $self->remove_child ($_);
      }

      ## Step 7, 8, 9, 10
      for my $node (@{$doc->child_nodes}) {
        $self->append_child ($self->adopt_node ($node));
      }

      return unless defined wantarray;
    }

    ## TODO: This serializer is currently not conformant to HTML5 spec.
    require Whatpm::XMLSerializer;
    my $r = '';
    for (@{$self->child_nodes}) {
      $r .= ${ Whatpm::XMLSerializer->get_outer_xml ($_, sub {
        ## TODO: INVALID_STATE_ERR
      }) };
    }
    return $r;
  }
} # inner_html

sub manakai_is_html ($;$) {
  if (@_ > 1) {
    if ($_[1]) {
      ${$_[0]}->{manakai_is_html} = 1;
    } else {
      delete ${$_[0]}->{manakai_is_html};
      delete ${$_[0]}->{manakai_compat_mode};
    }
  }
  return ${$_[0]}->{manakai_is_html};
} # manakai_is_html

package Message::IF::Document;
package Message::IF::DocumentTraversal;
package Message::IF::DocumentXDoctype;
package Message::IF::DocumentSelector;
package Message::IF::HTMLDocument;

package Message::DOM::DOMImplementation;

sub create_document ($;$$$) {
  my $r = Message::DOM::Document->____new ($_[0]);

  if (defined $_[2]) {
    local $Error::Depth = $Error::Depth + 1;
    $r->append_child ($r->create_element_ns ($_[1], $_[2])); # NAMESPACE_ERR
    ## NOTE: manakai might raise DOMExceptions in cases not defined
    ## in DOM3Core spec: XMLNSPREFIX_NONXMLNSNS_ERR,
    ## XMLNS_NONXMLNSNS_ERR, and NONXMLNSPREFIX_XMLNSNS_ERR.
  } elsif (defined $_[1]) {
    report Message::DOM::DOMException
        -object => $_[0],
        -type => 'NAMESPACE_ERR',
        -subtype => 'QNAME_NULLNS_ERR';
  }

  if (defined $_[3]) {
    if ($_[3]->parent_node) {
      report Message::DOM::DOMException
          -object => $_[0],
          -type => 'WRONG_DOCUMENT_ERR',
          -subtype => 'INUSE_DOCTYPE_ERR';
    }
    local $Error::Depth = $Error::Depth + 1;
    $r->insert_before ($_[3], $r->first_child); # EXTERNAL_OBJECT_ERR
  }

  return $r;
} # create_document

=head1 LICENSE

Copyright 2007 Wakaba <w@suika.fam.cx>

This program is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.

=cut

1;
## $Date: 2007/07/29 08:31:14 $