XMLReader类

XmlReader允许您从流或者XML文档中访问XML数据。这个类提供了对XML数据快速、非缓存、只读、只向前的访问方式。

此扩展需要 libxml PHP 扩展。这表示需要使用--enable-libxml，尽管这将隐式完成因为 libxml 是缺省开启的。

安装

XMLReader扩展最初是PHP 5的PECL扩展。它后来从PHP 5.1.0开始被移动到PHP源代码（捆绑），并在PHP 5.1.2以后默认启用.

此扩展默认为启用,编译时可通过下列选项禁用：--disable-xmlreader

XMLReader类

(PHP 5 >= 5.1.0, PHP 7)

XMLReader扩展是一个XML Pull解析器。读卡器充当一个光标，在文档流上前进并在途中的每个节点处停止。

XMLReader 
{
	/* 常量 */
	const int NONE = 0 ;
	const int ELEMENT = 1 ;
	const int ATTRIBUTE = 2 ;
	const int TEXT = 3 ;
	const int CDATA = 4 ;
	const int ENTITY_REF = 5 ;
	const int ENTITY = 6 ;
	const int PI = 7 ;
	const int COMMENT = 8 ;
	const int DOC = 9 ;
	const int DOC_TYPE = 10 ;
	const int DOC_FRAGMENT = 11 ;
	const int NOTATION = 12 ;
	const int WHITESPACE = 13 ;
	const int SIGNIFICANT_WHITESPACE = 14 ;
	const int END_ELEMENT = 15 ;
	const int END_ENTITY = 16 ;
	const int XML_DECLARATION = 17 ;
	const int LOADDTD = 1 ;
	const int DEFAULTATTRS = 2 ;
	const int VALIDATE = 3 ;
	const int SUBST_ENTITIES = 4 ;
	/* 属性 */
	public readonly int $attributeCount ;
	public readonly string $baseURI ;
	public readonly int $depth ;
	public readonly bool $hasAttributes ;
	public readonly bool $hasValue ;
	public readonly bool $isDefault ;
	public readonly bool $isEmptyElement ;
	public readonly string $localName ;
	public readonly string $name ;
	public readonly string $namespaceURI ;
	public readonly int $nodeType ;
	public readonly string $prefix ;
	public readonly string $value ;
	public readonly string $xmlLang ;
	/* 方法 */
	public close ( void ) : bool
	public expand ([ DOMNode $basenode ] ) : DOMNode
	public getAttribute ( string $name ) : string
	public getAttributeNo ( int $index ) : string
	public getAttributeNs ( string $localName , string $namespaceURI ) : string
	public getParserProperty ( int $property ) : bool
	public isValid ( void ) : bool
	public lookupNamespace ( string $prefix ) : string
	public moveToAttribute ( string $name ) : bool
	public moveToAttributeNo ( int $index ) : bool
	public moveToAttributeNs ( string $localName , string $namespaceURI ) : bool
	public moveToElement ( void ) : bool
	public moveToFirstAttribute ( void ) : bool
	public moveToNextAttribute ( void ) : bool
	public next ([ string $localname ] ) : bool
	public open ( string $URI [, string $encoding [, int $options = 0 ]] ) : bool
	public read ( void ) : bool
	public readInnerXml ( void ) : string
	public readOuterXml ( void ) : string
	public readString ( void ) : string
	public setParserProperty ( int $property , bool $value ) : bool
	public setRelaxNGSchema ( string $filename ) : bool
	public setRelaxNGSchemaSource ( string $source ) : bool
	public setSchema ( string $filename ) : bool
	public xml ( string $source [, string $encoding [, int $options = 0 ]] ) : bool
}

属性

• $attributeCount：The number of attributes on the node
• $baseURI：The base URI of the node
• $depth：Depth of the node in the tree, starting at 0
• $hasAttributes：Indicates if node has attributes
• $hasValue：Indicates if node has a text value
• $isDefault：Indicates if attribute is defaulted from DTD
• $isEmptyElement：Indicates if node is an empty element tag
• $localName：The local name of the node
• $name：The qualified name of the node
• $namespaceURI：The URI of the namespace associated with the node
• $nodeType：The node type for the node
• $prefix：The prefix of the namespace associated with the node
• $value：The text value of the node
• $xmlLang：The xml:lang scope which the node resides

预定义常量

XMLReader Node Types

• XMLReader::NONE：No node type
• XMLReader::ELEMENT：Start element
• XMLReader::ATTRIBUTE：Attribute node
• XMLReader::TEXT：Text node
• XMLReader::CDATA：CDATA node
• XMLReader::ENTITY_REF：Entity Reference node
• XMLReader::ENTITY：Entity Declaration node
• XMLReader::PI：Processing Instruction node
• XMLReader::COMMENT：Comment node
• XMLReader::DOC：Document node
• XMLReader::DOC_TYPE：Document Type node
• XMLReader::DOC_FRAGMENT：Document Fragment node
• XMLReader::NOTATION：Notation node
• XMLReader::WHITESPACE：Whitespace node
• XMLReader::SIGNIFICANT_WHITESPACE：Significant Whitespace node
• XMLReader::END_ELEMENT：End Element
• XMLReader::END_ENTITY：End Entity
• XMLReader::XML_DECLARATION：XML Declaration node

XMLReader Parser Options

• XMLReader::LOADDTD：Load DTD but do not validate
• XMLReader::DEFAULTATTRS：Load DTD and default attributes but do not validate
• XMLReader::VALIDATE：Load DTD and validate while parsing
• XMLReader::SUBST_ENTITIES：Substitute entities and expand references