CSS::DOM::Value - CSSValue class for CSS::DOM

CSS-DOM documentation Contained in the CSS-DOM distribution.

Index

Code Index:

NAME

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CSS::DOM::Value - CSSValue class for CSS::DOM

VERSION

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Version 0.14

SYNOPSIS

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  # ...

DESCRIPTION

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This module implements objects that represent CSS property values. It implements the DOM CSSValue interface.

This class is used only for custom values (neither primitive values nor lists) and the special 'inherit' value.

METHODS

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Object Methods

cssText

Returns a string representation of the attribute. Pass an argument to set it.

cssValueType

Returns one of the constants below.

Constructor

You probably don't need to call this, but here it is anyway:

  $val = new CSS::DOM::Value %arguments;

The hash-style %arguments are as follows:

type

CSS_INHERIT or CSS_CUSTOM

css

A string of CSS code. This is only used when TYPE is CSS_CUSTOM.

owner

The style object that owns this value; if this is omitted, then the value is read-only. The value object holds a weak reference to the owner.

property

The name of the CSS property to which this value belongs. cssText uses this to determine how to parse text passed to it.

CONSTANTS

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The following constants can be imported with use CSS::DOM::Value ':all'. They represent the type of CSS value.

CSS_INHERIT (0)
CSS_PRIMITIVE_VALUE (1)
CSS_VALUE_LIST (2)
CSS_CUSTOM (3)

SEE ALSO

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CSS::DOM

CSS::DOM::Value::Primitive

CSS::DOM::Value::List

CSS::DOM::Style

CSS-DOM documentation Contained in the CSS-DOM distribution. 
package CSS::DOM::Value;

$VERSION = '0.14';

use warnings; no warnings qw 'utf8 parenthesis';;
use strict;

use Carp;
use CSS::DOM::Constants;
use CSS'DOM'Exception 'NO_MODIFICATION_ALLOWED_ERR';
use Exporter 5.57 'import';
use Scalar'Util < weaken reftype >;

use constant 1.03 our $_const = {
    type => 0,
    valu => 1,
    ownr => 2,
    prop => 3,
};
{ no strict; delete @{__PACKAGE__.'::'}{_const => keys %{our $_const}} }

*EXPORT_OK = $CSS::DOM::Constants::EXPORT_TAGS{value};
our %EXPORT_TAGS = ( all => \our @EXPORT_OK );

sub new {
	my $self = bless[], shift;
	my %args = @_;
	my $type = $self->[type] = $args{type};
	$type == CSS_CUSTOM
	? !exists $args{value} && croak
	   'new CSS::DOM::Value(type => CSS_CUSTOM) requires a value'
	: $type == CSS_INHERIT
		|| croak "Type must be CSS_CUSTOM or CSS_INHERIT";

	@$self[valu,ownr,prop] = @args{< value owner property >};
	weaken $$self[ownr];

	$self;
}

sub cssValueType { shift->[type] }

sub cssText {
	my $self = shift;
	my $old = $self->[type] == CSS_CUSTOM
		? $self->[valu] : 'inherit'
	 if defined wantarray;
	if(@_) {
		die new CSS'DOM'Exception
		  NO_MODIFICATION_ALLOWED_ERR,
		 "Unowned value objects cannot be modified"
		   unless my $owner = $self->[ownr];
		die new CSS'DOM'Exception
		  NO_MODIFICATION_ALLOWED_ERR,
		 "CSS::DOM::Value objects that do not know to which "
		 ."property they belong cannot be modified"
		   unless my $prop = $self->[prop];

		if(
		 my @arsg
		  = $owner->property_parser->match($prop, $_[0])
		) {
			_apply_args_to_self($self,$owner,$prop,@arsg);
		}

		if(my $mh = $owner->modification_handler) {
			&$mh();
		}
	}
	$old
}

sub _apply_args_to_self {
  my($self,$owner,$prop,@arsg) = @_;
 _load_if_necessary($arsg[1]);
  my $new = $arsg[1]->new(
   owner => $owner, property => $prop, @arsg[2...$#arsg]
  );
  reftype $self eq "HASH"
   ?  %$self = %$new
   : (@$self = @$new);
  bless $self, ref $new unless ref $new eq ref $self;
}

sub _load_if_necessary {
 $_[0]->can('new')
  || do {
      (my $pack = $_[0]) =~ s e::e/egg;
      require "$pack.pm";
     };
}

                              !()__END__()!