使用xpath从网页刮取特定文本

问题描述：

I've searched and tried multiple ways to get this but I'm not sure why it won't find most of the information on the webpage.

Page to scrape: https://m.safeguardproperties.com/

Info needed: Version number for PhotoDirect for Apple (currently 4.4.0)

Xpath to text needed (I think) : /html/body/div[1]/div[2]/div[1]/div[4]/div[3]/a

Attempts:

<?php

$file = "https://m.safeguardproperties.com/";
$doc = new DOMDocument();
$doc->loadHTMLFile($file);

$xpath = new DOMXpath($doc);

$elements = $xpath->query("/html/body/div[1]/div[2]/div[1]/div[4]/div[3]/a");

echo "<PRE>";

if (!is_null($elements)) {
  foreach ($elements as $element) {
      var_dump ($element);
    echo "<br/>[". $element->nodeName. "]";

    $nodes = $element->childNodes;
    foreach ($nodes as $node) {
      echo $node->nodeValue. "
";
    }
  }
}

echo "</PRE>";

?>

Second Attempt:

<?PHP
$file = "https://m.safeguardproperties.com/";
$doc = new DOMDocument();
$doc->loadHTMLFile($file);

echo '<pre>';

  // trying to find all links in document to see if I can see the correct one
  $links = [];
  $arr = $doc->getElementsByTagName("a");

  foreach($arr as $item) { 
    $href =  $item->getAttribute("href");
    $text = trim(preg_replace("/[
]+/", " ", $item->nodeValue));
    $links[] = [
      'href' => $href,
      'text' => $text
    ];
  }

var_dump($links);
echo '</pre>';
?>

我已经搜索并尝试了多种方法来获取此信息，但我不确定为什么它找不到网页上的信息。 p>

要刮的页面： https：/ /m.safeguardproperties.com/ p>

需要的信息： PhotoDirect for Apple的版本号（目前为4.4.0） p>

Xpath 需要的文字（我认为）：/ html / body / div [1] / div [2] / div [1] / div [4] / div [3] / a p>

尝试： p>

 ＆lt;？php 
 
 $ file =“https://m.safeguardproperties.com/";
$doc = new DOMDocument（）;  
 $ doc-＆gt; loadHTMLFile（$ file）; 
 
 $ xpath = new DOMXpath（$ doc）; 
 
 $ elements = $ xpath-＆gt; query（“/ html / body / div [1  ] / div [2] / div [1] / div [4] / div [3] / a“）; 
 
echo”＆lt; PRE＆gt;“; 
 
if（！is_null（$ elements））{  
 foreach（$ elements as $ element）{
 var_dump（$ element）; 
 echo“＆lt; br /＆gt; [”。  $元素 - ＆GT;节点名称。  “]”; 
 
 $ nodes = $ element-＆gt; childNodes; 
 foreach（$ nodes as $ node）{
 echo $ node-＆gt; nodeValue。  “
”; 
} 
} 
} 
 
echo“＆lt; / PRE＆gt;”; 
 
？＆gt; 
  code>  pre> 
 
  第二次尝试： p> 
 
 
 ＆lt;？PHP 
 $ file =“https://m.safeguardproperties.com/";
$doc = new DOMDocument（）; \  n $ doc-＆gt; loadHTMLFile（$ file）; 
 
echo'＆lt; pre＆gt;'; 
 
 //尝试查找文档中的所有链接，看看我是否能看到正确的链接
 $ links =  []; 
 $ arr = $ doc-＆gt; getElementsByTagName（“a”）; 
 
 foreach（$ arr as $ item）{
 $ href = $ item-＆gt; getAttribute（“href”）;  
 $ text = trim（preg_replace（“/ [
 
] + /”，“”，$ item-＆gt; nodeValue））; 
 $ links [] = [
'href'=＆gt;  $ href，
'text'=＆gt;  $ text 
]; 
} 
 
var_dump（$ links）; 
echo'＆lt; / pre＆gt;'; 
？＆gt; 
  code>  pre> 
  div>

答

For that particular website, the versions are being loaded from JSON data client side, you won't find them in the base document.

http://m.safeguardproperties.com/js/photodirect.json

This was located by comparing the original document source to the finished DOM and inspecting the network activity in the developer console.

$url = 'https://m.safeguardproperties.com/js/photodirect.json';
$json = file_get_contents( $url );
$object = json_decode( $json );
echo $object->ios->version; //4.4.0

Please respect other websites and cache your GET request.

使用xpath从网页刮取特定文本

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