DomNode->add_namespace

(no version information, might be only in CVS)

DomNode->add_namespace --  Adds a namespace declaration to a node

说明

class DOMNode {

bool add_namespace ( string uri, string prefix )

}

This method adds a namespace declaration to a node.

注: This method is not part of the DOM specification.

参数

uri

The namespace URI of the node.

prefix

The namespace prefix of the node.

返回值

如果成功则返回 TRUE,失败则返回 FALSE

Migrating to PHP 5

You can set the namespace URI and prefix of a DOMElement or a DOMAttr at creation time by using DOMDocument->createElementNS() or DOMDocument->createAttributeNS().

注: Remember the an attribute does not inherit its namespace from the element it is attached to.


add a note add a note User Contributed Notes
tkearns at fastmail dot fm
17-Sep-2003 05:02
<?php
// EXAMPLE USING PHP 4.3.3
$objDoc = domxml_new_doc("1.0");
$ndRoot = $objDoc->create_element("root");
$ndRoot = $objDoc->append_child($ndRoot);

$ndRoot->set_namespace("foo/the/bar");
// using ramdom prefix, produces something like
// <a3767:root xmlns:a3767="foo/the/bar"/>

$ndRoot->set_namespace("yet/another/namespace","yan");
// modifies the existing prefix (again) produces something like
// <yan:root xmlns:a3767="foo/the/bar" xmlns:yan="yet/another/namespace"/>

$ndRoot->set_namespace("yet/another/namespace","foo");
// attempt to use the same ns id has again no effect. element is un-touched
// <yan:root xmlns:a3767="foo/the/bar" xmlns:yan="yet/another/namespace"/>

$ndRoot->set_namespace("new/ns/no/prefix");
// munges the existing element prefix again as well as adding declaration
// <a1757:root
//    xmlns:a3767="foo/the/bar"
//    xmlns:yan="yet/another/namespace"
//    xmlns:a1757="new/ns/no/prefix"
// />

/*
It seems that the only way to add a DEFAULT namespace to a node (without
affecting the current prefix), is to use set_attribute("xmlns",$ndId).
*/

$ndRoot->set_attribute("xmlns","default/ns/no/prefix");
// now we have
// <a1757:root
//    xmlns:a3767="foo/the/bar"
//    xmlns:yan="yet/another/namespace"
//    xmlns:a1757="new/ns/no/prefix"
//    xmlns="default/ns/no/prefix"
// />

/*
Note that namespace declarations inserted using set_namespace are not classed as
attributes, so they do not show up in an attribute list. Since we set our
default namespace using the set_attribute() method, it is the only one that will
show up.
*/
var_dump($ndRoot->attributes());
// see that only the defaul namespace is returned because it is of type
// "domattribute" because we set it with an attribute method.

$ndRoot->set_attribute("xmlns:pfx","non/default/with/prefix");
// now we have
// <a1757:root
//    xmlns:a3767="foo/the/bar"
//    xmlns:yan="yet/another/namespace"
//    xmlns:a1757="new/ns/no/prefix"
//    xmlns="default/ns/no/prefix"
//    xmlns:pfx="non/default/with/prefix"
// />

/*
Any XML processor still regards it as a namespace declaration the same way
they recognise the other namespaces we declared. Problem for us is that we
cannot ascertain the existing namespace declarations on any element if they are
not declared using set_attribute. Furthermore, external files imported into
DOMXML objects do NOT have their namespace declarations detected as attributes -
and rightly so. But the problem arises that now there is no way to detect these
declarations.
*/

var_dump($ndRoot->attributes());
// Our new "xmlns:pfx" *attribute* now shows up because we set it with an
// attribute method and it is of type "domattribute". So what of our namespace
// declarations using set_namespace() then? Do they have a type?

/*
Well there doesn't seem to be any other dom type where our declarations can
reside. This is problably the reason why we have no way of detecting them.
It's important to note that when parsing in external XML files, the prefixed
namespace declarations do NOT show up in the list of attribute nodes.
*/

/*
I would also argue that destroying the existing element prefix by forcing the
[re]population of it with a new one when using set_namespace() should be
considdered "unexpected behaviour". If the user doesn not supply a prefix, then
it should be added as the default namespace (with no prefix).
Using set_attribute() is a workaround to the "problem" and not a solution.
*/

/*
The behaviour of set_namespace() is not the biggest problem though.
Inability to detect existing namespace declarations is. How do I find out if
a namespace with id of "yet/another/namespace" has been declared in this
element? The answer is I can't. And if I could, I would also want to know what
prefix it is using.
*/

echo htmlentities($objDoc->dump_mem(true));
?>