pro*_*son 148
更新:*[@class~='my-class']css选择器的Xpath版本
所以在我的评论下面回应hakre的评论后,我很好奇,并查看了背后的代码Zend_Dom_Query.看起来上面的选择器被编译为以下xpath(未经测试):
[contains(concat(' ', normalize-space(@class), ' '), ' my-class ')]
所以php将是:
$dom = new DomDocument();
$dom->load($filePath);
$finder = new DomXPath($dom);
$classname="my-class";
$nodes = $finder->query("//*[contains(concat(' ', normalize-space(@class), ' '), ' $classname ')]");
基本上,我们在这里所做的只是规范化class属性,以便即使单个类也以空格为界,并且完整的类列表以空格为界.然后用空格追加我们正在搜索的类.这样我们就可以有效地寻找并找到实例my-class.
使用xpath选择器？
$dom = new DomDocument();
$dom->load($filePath);
$finder = new DomXPath($dom);
$classname="my-class";
$nodes = $finder->query("//*[contains(@class, '$classname')]");
如果它只是一种类型的元素,您可以用*特定的标记名替换它.
如果您需要使用非常复杂的选择器进行大量操作,我建议使用Zend_Dom_Query哪种支持CSS选择器语法(la jQuery):
$finder = new Zend_Dom_Query($html);
$classname = 'my-class';
$nodes = $finder->query("*[class~=\"$classname\"]");
Tsc*_*cka 17
如果你希望得到没有zend的类的innerhtml,你可以使用这个:
$dom = new DomDocument();
$dom->load($filePath);
$classname = 'main-article';
$finder = new DomXPath($dom);
$nodes = $finder->query("//*[contains(concat(' ', normalize-space(@class), ' '), ' $classname ')]");
$tmp_dom = new DOMDocument();
foreach ($nodes as $node)
{
$tmp_dom->appendChild($tmp_dom->importNode($node,true));
}
$innerHTML.=trim($tmp_dom->saveHTML());
echo $innerHTML;
dav*_*dav 11
我认为接受的方式更好,但我想这可能也有效
function getElementByClass(&$parentNode, $tagName, $className, $offset = 0) {
$response = false;
$childNodeList = $parentNode->getElementsByTagName($tagName);
$tagCount = 0;
for ($i = 0; $i < $childNodeList->length; $i++) {
$temp = $childNodeList->item($i);
if (stripos($temp->getAttribute('class'), $className) !== false) {
if ($tagCount == $offset) {
$response = $temp;
break;
}
$tagCount++;
}
}
return $response;
}
还有一种不使用DomXPath或的方法Zend_Dom_Query。
基于dav的原始函数，我编写了以下函数，该函数返回其tag和class与参数匹配的父节点的所有子节点。
function getElementsByClass(&$parentNode, $tagName, $className) {
$nodes=array();
$childNodeList = $parentNode->getElementsByTagName($tagName);
for ($i = 0; $i < $childNodeList->length; $i++) {
$temp = $childNodeList->item($i);
if (stripos($temp->getAttribute('class'), $className) !== false) {
$nodes[]=$temp;
}
}
return $nodes;
}
假设您具有$html以下HTML 变量：
<html>
<body>
<div id="content_node">
<p class="a">I am in the content node.</p>
<p class="a">I am in the content node.</p>
<p class="a">I am in the content node.</p>
</div>
<div id="footer_node">
<p class="a">I am in the footer node.</p>
</div>
</body>
</html>
的使用getElementsByClass非常简单：
$dom = new DOMDocument('1.0', 'utf-8');
$dom->loadHTML($html);
$content_node=$dom->getElementById("content_node");
$div_a_class_nodes=getElementsByClass($content_node, 'div', 'a');//will contain the three nodes under "content_node".
DOMDocument的输入速度很慢,而phpQuery的内存泄漏问题也很糟糕.我最终使用:
https://github.com/wasinger/htmlpagedom
要选择一个班级:
include 'includes/simple_html_dom.php';
$doc = str_get_html($html);
$href = $doc->find('.lastPage')[0]->href;
我希望这对其他人也有帮助
PHP's native DOM handling is so absurdly bad, do yourself a favour and use this or any other modern HTML parsing package which can handle this within in few lines:
Install paquettg/php-html-parser with
composer require paquettg/php-html-parser
Then create a .php file in the same folder with this content
<?php
// load dependencies via Composer
require __DIR__ . '/vendor/autoload.php';
use PHPHtmlParser\Dom;
$dom = new Dom;
$dom->loadFromUrl("https://example.com");
$links = $dom->find('.classname a');
foreach ($links as $link) {
echo $link->getAttribute('href');
}
P.S. You'll find information on how to install Composer on Composer's homepage.