DOMDocument::createAttribute()

(PHP 5, PHP 7)

Create new attribute

说明

publicDOMDocument::createAttribute(string $name): DOMAttr

This function creates a new instance of class DOMAttr.此节点出现在文档中，除非是用诸如DOMNode->appendChild()等函数来将其插入。

参数

$name

The name of the attribute.

返回值

The new DOMAttr or FALSE if an error occurred.

错误／异常

DOM_INVALID_CHARACTER_ERR

Raised if$namecontains an invalid character.

参见

• DOMNode::appendChild() Adds new child at the end of the children
• DOMDocument::createAttributeNS() Create new attribute node with an associated namespace
• DOMDocument::createCDATASection() Create new cdata node
• DOMDocument::createComment() Create new comment node
• DOMDocument::createDocumentFragment() Create new document fragment
• DOMDocument::createElement() Create new element node
• DOMDocument::createElementNS() Create new element node with an associated namespace
• DOMDocument::createEntityReference() Create new entity reference node
• DOMDocument::createProcessingInstruction() Creates new PI node
• DOMDocument::createTextNode() Create new text node

Just in case it isn't clear (like I had), an example:
<?php
$domDocument = new DOMDocument('1.0', "UTF-8");
$domElement = $domDocument->createElement('field','some random data');
$domAttribute = $domDocument->createAttribute('name');
// Value for the created attribute
$domAttribute->value = 'attributevalue';
// Don't forget to append it to the element
$domElement->appendChild($domAttribute);
// Append it to the document itself
$domDocument->appendChild($domElement);
?>
Will output:
<?xml version="1.0" encoding="UTF-8"?>
<field name="attributevalue">some random data</field>

This may be obvious to most people, but it gave me a few minutes of head-scratching before I figured it out, but ampersands need to be properly escaped as HTML entities.
<?php
$doc= new DOMDocument('1.0', "UTF-8");
$invalid_elem = $doc->createElement('field', 'incorrect attribute');
$invalid_attr = $doc->createAttribute('name');
$invalid_attr->value = 'foo&bar';
$invalid_elem->appendChild($invalid_attr);
$doc->appendChild($invalid_elem);
$valid_elem = $doc->createElement('field', 'correct attribute');
$valid_attr = $doc->createAttribute('name');
$valid_attr->value = 'foo&amp;bar';
$valid_elem->appendChild($valid_attr);
$doc->appendChild($valid_elem);
?>
Will output:
<?xml version="1.0" encoding="UTF-8"?>
<field name="foo">incorrect attribute</field>
<field name="foo&bar">correct attribute</field>
As near as I can figure out, no exception is thrown for an invalid attribute. This will affect DOMDocuments created as HTML as well as XML.