manakai//DOM Perl Binding

Conformance

[48] Statements about conformance in this specification are only applied to implementations that support related feature. For example, MUST-level requirements for treatement of the EventHandler objects do not apply to implementations that do not support DOM Events module.

Objects and interfaces

[3] A DOM object, i.e. an object implementing one or more DOM interfaces, MUST be represented by a Perl object, i.e. a thingly referenced by some Perl references and blessed in a Perl class, unless otherwise specified. The Perl class MUST implement the DOM interfaces implemented by the DOM object.

Methods and attributes

[5] A DOM method MUST be implemented as a Perl method.

[6] A read-only DOM attribute MUST be implemented as a Perl method that returns the value contained in the DOM attribute. The Perl method MAY throw an implementation dependent exception if any argument is specified for the Perl method.

[7] A read-write DOM attribute MUST be implemented as a Perl method. The Perl method MUST return the value contained in the DOM attribute if no argument is specified for the Perl method (i.e. the only argument to the subroutine implementing the Perl method is the object itself). Otherwise, the Perl method MUST try to set the first argument specified for the method (i.e. the second argument to the subroutine implementing the Perl method) to the DOM attribute.

[8] A DOM parameter to a method is optional if either null or boolean false value is allowed to be specified to that parameter and any following DOM parameter is optional.

The Perl method MUST act as if an undef or a Perl false value, depending on the data type of the parameter, is specified to each optional parameter if no argument corresponding to that parameter is specified.

Constants

Exceptions and errors

[9] Throwing an exception MUST be implemented by Perl die function. If the exception is one defined in DOM specification, the argument to the die function MUST be an object implementing the associated exception interface.

Events

Naming Rule

[15] Names of DOM methods and attributes MUST be mapped to Perl method (subroutine) name by following algorithm:

1. Let n as the name of a DOM method or attribute.
2. If the first column of the table >>14 contains n, then return the name contained in the cell in the second column of the same row.
3. Otherwise, replace a sequence of one or more uppercase letters at the end of n, if any, by the lowercase variant of the sequence.
4. Replace any sequence of two or more uppercase letters in n by a sequence of a LOW LINE character, the lowercase variant of the sequence except the last letter, a LOW LINE character, and the lowercase variant of the last letter of the sequence.
5. Replace any uppercase letter by a LOW LINE character followed by the lowercase variant of the letter.
6. Then, return n.

[14] Exceptions.

Data types

[10] In this section, number types includes: long, unsigned long, unsigned long long, short, and unsigned short.

[11] If the return value of the DOM method or the DOM attribute is of number type and a Perl method return a value in that type, jt MUST return a value that can be evaluated as a number (by, e.g., 0+ operation).

[12] If a DOM method parameter or the DOM attribute is of number type and it is necessary for a Perl method to get the specified value, it MAY evaluate the specified value as a value (by, e.g., 0+ operation).

    is expected to be evaluated in the Boolean context.

    IDL type <TYPE^^DISCore|QName::idl|any> is corresponding to any scalar valu\
e
    in Perl.  IDL type <TYPE^^DISCore|QName::idl|Object> is bound to object.

  The <TYPE::MIString> type is bound to Perl string value and
    expected to be evaluated in the string context.  A <TYPE::MIString>
    value <kwd:MUST> be interpreted as a sequence of characters rather than
    a sequence of bytes or octets.  If it is represented
    internally as a byte string, i.e. the utf8 flag turned off,
    it <kwd:MUST> be interpreted as a ISO/IEC 8859-1 <bibref::ISO8859-1> string\
.

Security

Features

DOMImplementationRegistry

[16] The variable $Message::DOM::DOMImplementationRegistry MUST contain a value via which methods provided by DOMImplementationRegistry object can be invoked.

$Message::DOM::DOMImplementationRegistry->get_dom_implementation

returns a DOM implementation.

Operator overloading

[18] Unless otherwise specified, an object implementing DOM interface MUST NOT overload an operator by use overload in a way that breaks how that operator works for normal objects.

[28] In any way, when an operator is overloaded, it MUST be consistent with other operators.

my $eq = $a eq $b;
my $ne = $a ne $b;
die unless ($eq and not $ne) or (not $eq and $ne);

... must not die.

Function-like interfaces

[22] Several interfaces are defined as function-like. Only Perl native CODE references, i.e. values whose ref is CODE, and objects for which the &{} operation is defined MUST be treated as if they implement the function-like interfaces and are referred to as objects implementing the function-like interfaces. Each function-like interface has a method, typically named as handleEvent. Invoking that method on the object implementing a function-like interface from another language binding invokes the object itself, by &{} operation. In the Perl binding itself, however, the method of the interface is not directly accessible on the object implementing the interface.

[43] Function-like interfaces are:

• DOMErrorHandler
• EventHandler
• NodeFilter
• UserDataHandler
• VoidCallback

[44] When the method would be invoked, the &{} operation MUST be performed over the object with appropriate arguments. The return value of the &{} operation MUST be treated as if the return value of the method. If the &{} operation results in an exception is raised, it MUST be treated as if it is an exception raised by the method.

$node->add_event_listener ('click', sub {
  my $ev = shift;
  print $ev->details, "\n";
  return 0;
});

would make the subroutine invoked when the node is clicked. The subroutine, implementing the EventHandler interface and treated as if it is the handleEvent method, would prints the number of clicks and then cancel the default action for the event.

[45] Though in some of function-like interfaces constants are defined, they are not accessible via the object implemeting that interface in the Perl binding. Other interface might provide such constants alternatively. For example, objects implementing the Node interface provides contants in UserDataHandler interface (see >>42).

Specifics

my $c1 = $node->child_nodes;
my $c2 = $node->child_nodes;
die unless $c1 eq $c2;

sub {
  my $prefix = $_[0];
  if (UNIVERSAL::can ($obj, 'lookup_namespace_uri')) {
    return $obj->lookup_namespace_uri ($prefix);
  } else {
    return $obj->($prefix);
  }
}

References

memo

[35]

[36]

[37]

[38]

[39] >>38 $SourceClass (名無しさん)

[40]

(名無しさん)

[41]

[49]

In binding languages that support setting to a readonly attribute setting media to a string must set the value of mediaText on the MediaList object.

[CSSOM]

(名無しさん)