DOMXPath->query()

(No version information available, might be only in CVS)

DOMXPath->query() — Evaluates the given XPath expression

说明

DOMXPath

DOMNodeList query ( string $expression [, DOMNode $contextnode ] )

Executes the given XPath expression .

参数

expression: The XPath expression to execute.
contextnode: The optional contextnode can be specified for doing relative XPath queries. By default, the queries are relative to the root element.

返回值

Returns a DOMNodeList containing all nodes matching the given XPath expression . Any expression which do not return nodes will return an empty DOMNodeList.

范例

Example#1 Getting all the english books


<?php

$doc = new DOMDocument;

// We don't want to bother with white spaces
$doc->preserveWhiteSpace = false;

$doc->Load('book.xml');

$xpath = new DOMXPath($doc);

// We starts from the root element
$query = '//book/chapter/para/informaltable/tgroup/tbody/row/entry[. = "en"]';

$entries = $xpath->query($query);

foreach ($entries as $entry) {
    echo "Found {$entry->previousSibling->previousSibling->nodeValue}," .
         " by {$entry->previousSibling->nodeValue}\n";
}
?>

上例将输出：

Found The Grapes of Wrath, by John Steinbeck
Found The Pearl, by John Steinbeck

We can also use the contextnode parameter to shorten our expression:


<?php

$doc = new DOMDocument;
$doc->preserveWhiteSpace = false;

$doc->load('book.xml');

$xpath = new DOMXPath($doc);

$tbody = $doc->getElementsByTagName('tbody')->item(0);

// our query is relative to the tbody node
$query = 'row/entry[. = "en"]';

$entries = $xpath->query($query, $tbody);

foreach ($entries as $entry) {
    echo "Found {$entry->previousSibling->previousSibling->nodeValue}," .
         " by {$entry->previousSibling->nodeValue}\n";
}
?>

参见

DOMXPath->evaluate()


	PHP5中文手册 DOMXPath->evaluate() DOMXPath->registerNamespace() DOM PHP Manual DOMXPath->query() (No version information available, might be only in CVS) DOMXPath->query() — Evaluates the given XPath expression 说明 DOMXPath DOMNodeList query ( string `$expression` [, DOMNode `$contextnode` ] ) Executes the given XPath `expression` . 参数 `expression` The XPath expression to execute. `contextnode` The optional `contextnode` can be specified for doing relative XPath queries. By default, the queries are relative to the root element. 返回值 Returns a DOMNodeList containing all nodes matching the given XPath `expression` . Any expression which do not return nodes will return an empty DOMNodeList. 范例 Example#1 Getting all the english books <?php $doc = new DOMDocument; // We don't want to bother with white spaces $doc->preserveWhiteSpace = false; $doc->Load('book.xml'); $xpath = new DOMXPath($doc); // We starts from the root element $query = '//book/chapter/para/informaltable/tgroup/tbody/row/entry[. = "en"]'; $entries = $xpath->query($query); foreach ($entries as $entry) { echo "Found {$entry->previousSibling->previousSibling->nodeValue}," . " by {$entry->previousSibling->nodeValue}\n"; } ?> 上例将输出： Found The Grapes of Wrath, by John Steinbeck Found The Pearl, by John Steinbeck We can also use the `contextnode` parameter to shorten our expression: `<?php $doc = new DOMDocument; $doc->preserveWhiteSpace = false; $doc->load('book.xml'); $xpath = new DOMXPath($doc); $tbody = $doc->getElementsByTagName('tbody')->item(0); // our query is relative to the tbody node $query = 'row/entry[. = "en"]'; $entries = $xpath->query($query, $tbody); foreach ($entries as $entry) { echo "Found {$entry->previousSibling->previousSibling->nodeValue}," . " by {$entry->previousSibling->nodeValue}\n"; } ?>` 参见 DOMXPath->evaluate() DOMXPath->evaluate() DOMXPath->registerNamespace() DOM PHP Manual