php 使用 DOMdocument() 方法通过 ClassName 获取元素
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Get Element by ClassName with DOMdocument() Method
提问by justberare
Here is what I am trying to achieve : retrieve all products on a page and put them into an array. Here is the code I am using :
这是我想要实现的目标：检索页面上的所有产品并将它们放入一个数组中。这是我正在使用的代码：
$page2 = curl_exec($ch);
$doc = new DOMDocument();
@$doc->loadHTML($page2);
$nodes = $doc->getElementsByTagName('title');
$noders = $doc->getElementsByClassName('productImage');
$title = $nodes->item(0)->nodeValue;
$product = $noders->item(0)->imageObject.src;
It works for the $title butnot for the product. For info, in the HTML code the img tag looks like this :
它适用于$title but非产品。有关信息，在 HTML 代码中，img 标签如下所示：
<img alt="" class="productImage" data-altimages="" src="xxxx">
I have been looking at this (PHP DOMDocument how to get element?) but I still don't understand how to make it work.
我一直在看这个（PHP DOMDocument 如何获取元素？）但我仍然不明白如何使它工作。
PS : I get this error :
PS：我收到此错误：
Call to undefined method
DOMDocument::getElementsByclassName()
调用未定义的方法
DOMDocument::getElementsByclassName()
回答by justberare
I finally used the following solution :
我最终使用了以下解决方案：
$classname="blockProduct";
$finder = new DomXPath($doc);
$spaner = $finder->query("//*[contains(@class, '$classname')]");
回答by Ulad Kasach
https://stackoverflow.com/a/31616848/3068233
https://stackoverflow.com/a/31616848/3068233
Linking this answer as it helped me the most with this problem.
链接这个答案，因为它对我解决这个问题的帮助最大。
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;
}
Theres the code and heres the usage
代码如下，用法如下
$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');
回答by Mahbub Alam
function getElementsByClassName($dom, $ClassName, $tagName=null) {
if($tagName){
$Elements = $dom->getElementsByTagName($tagName);
}else {
$Elements = $dom->getElementsByTagName("*");
}
$Matched = array();
for($i=0;$i<$Elements->length;$i++) {
if($Elements->item($i)->attributes->getNamedItem('class')){
if($Elements->item($i)->attributes->getNamedItem('class')->nodeValue == $ClassName) {
$Matched[]=$Elements->item($i);
}
}
}
return $Matched;
}
// usage
$dom = new \DOMDocument('1.0');
@$dom->loadHTML($html);
$elementsByClass = getElementsByClassName($dom, $className, 'h1');
