如何使用 PHP 从 class 名称的 HTML 中获取元素和子元素？

Question

我有一个 HTML 文件，其中的曲目在列表中。我想为每个轨道创建一个 PHP 对象并将所有对象保存到一个 PHP-Array.

HTML DOM 在我的 test.html 文件中：

<ul>
    <li class="track">
        <span id="primary-info">
            <span class="interpret">Lorem ipsum</span>
            <span class="title">dolor sit amet</span>
        </span>
        <span class="secondary-info">
            <span class="playtime">6:00</span>
            <span class="label">consetetur</span>
        </span>
    </li>

    <li class="track">
        <span id="primary-info">
            <span class="interpret">sed diam</span>
            <span class="title">nonumy eirmod</span>
        </span>
        <span class="secondary-info">
            <span class="playtime">7:00</span>
            <span class="label">invidunt</span>
        </span>
    </li>

</ul>

我的PHP代码：

    <?php

    $lTracklistArr = [];

    // get the html
    $HTML = file_get_contents("http://localhost/test.html");

    // load the dom
    $lDoc = new DOMDocument();
    $lDoc->loadHTML($HTML);

    // create XPath obj
    $XPath = new DOMXPath($lDoc);

    // get all tracks
    $lTracks = $XPath->query("//*[@class='track']");

    $i = 0;
    while($lTracks->item($i))
    {
        // How can I get the values from the sub-elements from the DOM?
        $lInterpret = $lTracks->item($i)-> ?
        $lTitle = $lTracks->item($i)-> ?
        $lPlaytime = $lTracks->item($i)-> ?
        $lLabel = $lTracks->item($i)-> ?

        $lTracklistArr[] = new Track($lInterpret, $lTitle, $lPlaytime, $lLabel);

        $i++; 
    }

    // show tracklist
    print_r($lTracklistArr);

    // PHP class about one track
    Class Track
    {
        var $m_Interpret;
        var $m_Title;
        var $m_Playtime;
        var $m_Label;

        public function __construct($pInterpret, $pTitle, $pPlaytime, $pLabel) 
        {
            $m_Interpret = $pInterpret;
            $m_Title = $pTitle;
            $m_Playtime = $pPlaytime;
            $m_Label = $pLabel;
        }
    }
?>

拿到曲目没问题。但是我无法通过 class 名称从子元素中获取值。

注意：曲目中 DOM 的顺序可以更改。需要通过class名称获取元素。

Answer 1

您可以使用 SimpleXML 执行此操作：

<?php


$lTracklistArr = [];

// get the html
$HTML = file_get_contents("http://localhost/test.html");


$classes = ["interpret", "title", "playtime", "label"];


$data = simplexml_load_string($HTML);


foreach ($data->li as $e) {

    $data = [];

    $attr = (array) $e->attributes();

    if (    !isset($attr["@attributes"]["class"])
        ||  ("track" !== $attr["@attributes"]["class"])
    ) {
        continue;
    }


    foreach ($e->span as $e2) {
        foreach ($e2->span as $e3) {
            $attr = (array) $e3->attributes();

            if (!isset($attr["@attributes"]["class"])) {
                continue;
            }

            $class = $attr["@attributes"]["class"];

            if (!in_array($class, $classes)) {
                continue;
            }

            $data[$class] = (string) $e3;
        }
    }

    $lTracklistArr[] = new Track($data["interpret"], $data["title"], $data["playtime"], $data["label"]);

}


// show tracklist
var_dump($lTracklistArr);

// PHP class about one track
Class Track
{
    var $m_Interpret;
    var $m_Title;
    var $m_Playtime;
    var $m_Label;

    public function __construct($pInterpret, $pTitle, $pPlaytime, $pLabel) 
    {
        $this->m_Interpret = $pInterpret;
        $this->m_Title = $pTitle;
        $this->m_Playtime = $pPlaytime;
        $this->m_Label = $pLabel;
    }
}

Answer 2

当我将每个轨道的 DOMElement 转换为 html 并将 html 再次转换为 DOMXPath:

时，我可以对每个轨道使用 xpath

$lTracklistArr = [];

// get the html
$HTML = file_get_contents("http://localhost/test.html");

$XPath = GetXPathByHTML($HTML);

// get all tracks
$lTracks = $XPath->query("//*[@class='track']");

$i = 0;
while($lTracks->item($i))
{               
    //save DOMElement of the Track as HTML and Convert it back into DOMXPath
    $XPathTrack = GetXPathByHTML($lTracks->item($i)->ownerDocument->saveHTML( $lTracks->item($i) ));

    // How can I get the values from the sub-elements from the DOM?
    $lInterpret = $XPathTrack->query("//*[@class='interpret']")->item(0)->nodeValue;
    $lTitle =  $XPathTrack->query("//*[@class='title']")->item(0)->nodeValue;
    $lPlaytime =  $XPathTrack->query("//*[@class='playtime']")->item(0)->nodeValue;
    $lLabel =  $XPathTrack->query("//*[@class='label']")->item(0)->nodeValue;

    $lTracklistArr[] = new Track($lInterpret, $lTitle, $lPlaytime, $lLabel);

    $i++; 
}

function GetXPathByHTML($pHTML) 
{
    // load the dom
    $lDoc = new DOMDocument();
    libxml_use_internal_errors(true); // suppress warnings
    $lDoc->loadHTML($pHTML);

    // create XPath obj
    return new DOMXPath($lDoc);
}

这对我有用。 A print_r($lTracklistArr) 正确显示结果：

Array ( [0] => Track Object ( [m_Interpret] => Lorem ipsum [m_Title] => dolor sit amet [m_Playtime] => 6:00 [m_Label] => consetetur ) [1] => Track Object ( [m_Interpret] => sed diam [m_Title] => nonumy eirmod [m_Playtime] => 7:00 [m_Label] => invidunt ) )

如何使用 PHP 从 class 名称的 HTML 中获取元素和子元素？

How can I get elements and child elements from an HTML by class name using PHP?

html

php

domdocument