PHP扩展之XML操作（四）——XMLReader

一、概述及安装

The XMLReader extension is an XML Pull parser. The reader acts as a cursor going forward on the document stream and stopping at each node on the way.

It is important to note that internally, libxml uses the UTF-8 encoding and as such, the encoding of the retrieved contents will always be in UTF-8 encoding.

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。

The XMLReader extension was initially a PECL extension for PHP 5. It was later moved to the PHP source (bundled) as of PHP 5.1.0, and later enabled by default as of PHP 5.1.2.

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

二、XMLReader类及其成员函数
XMLReader::close — Close the XMLReader input
XMLReader::expand — Returns a copy of the current node as a DOM object
XMLReader::getAttribute — Get the value of a named attribute
XMLReader::getAttributeNo — Get the value of an attribute by index
XMLReader::getAttributeNs — Get the value of an attribute by localname and URI
XMLReader::getParserProperty — Indicates if specified property has been set
XMLReader::isValid — Indicates if the parsed document is valid
XMLReader::lookupNamespace — Lookup namespace for a prefix
XMLReader::moveToAttribute — Move cursor to a named attribute
XMLReader::moveToAttributeNo — Move cursor to an attribute by index
XMLReader::moveToAttributeNs — Move cursor to a named attribute
XMLReader::moveToElement — Position cursor on the parent Element of current Attribute
XMLReader::moveToFirstAttribute — Position cursor on the first Attribute
XMLReader::moveToNextAttribute — Position cursor on the next Attribute
XMLReader::next — Move cursor to next node skipping all subtrees
XMLReader::open — Set the URI containing the XML to parse
XMLReader::read — Move to next node in document
XMLReader::readInnerXML — Retrieve XML from current node
XMLReader::readOuterXML — Retrieve XML from current node, including it self
XMLReader::readString — Reads the contents of the current node as a string
XMLReader::setParserProperty — Set parser options
XMLReader::setRelaxNGSchema — Set the filename or URI for a RelaxNG Schema
XMLReader::setRelaxNGSchemaSource — Set the data containing a RelaxNG Schema
XMLReader::setSchema — Validate document against XSD
XMLReader::XML — Set the data containing the XML to parse