How to parse HTML in PHP?

I know we can use PHP DOM to parse HTML using PHP. I found a lot of questions here on Stack Overflow too. But I have a specific requirement. I have an HTML content like below

<p class="Heading1-P">
    <span class="Heading1-H">Chapter 1</span>
</p>
<p class="Normal-P">
    <span class="Normal-H">This is chapter 1</span>
</p>
<p class="Heading1-P">
    <span class="Heading1-H">Chapter 2</span>
</p>
<p class="Normal-P">
    <span class="Normal-H">This is chapter 2</span>
</p>
<p class="Heading1-P">
    <span class="Heading1-H">Chapter 3</span>
</p>
<p class="Normal-P">
    <span class="Normal-H">This is chapter 3</span>
</p>

I want to parse the above HTML and save the content into two different arrays like:

$heading and $content

$heading = array('Chapter 1','Chapter 2','Chapter 3');
$content = array('This is chapter 1','This is chapter 2','This is chapter 3');

I can achieve this simply using jQuery. But I am not sure, if that's the right way. It would be great if someone can point me to the right direction. Thanks in advance.


Solution 1:

I have used domdocument and domxpath to get the solution, you can find it at:

<?php
$dom = new DomDocument();
$test='<p class="Heading1-P">
    <span class="Heading1-H">Chapter 1</span>
</p>
<p class="Normal-P">
    <span class="Normal-H">This is chapter 1</span>
</p>
<p class="Heading1-P">
    <span class="Heading1-H">Chapter 2</span>
</p>
<p class="Normal-P">
    <span class="Normal-H">This is chapter 2</span>
</p>
<p class="Heading1-P">
    <span class="Heading1-H">Chapter 3</span>
</p>
<p class="Normal-P">
    <span class="Normal-H">This is chapter 3</span>
</p>';

$dom->loadHTML($test);
$xpath = new DOMXpath($dom);
    $heading=parseToArray($xpath,'Heading1-H');
    $content=parseToArray($xpath,'Normal-H');

var_dump($heading);
echo "<br/>";
var_dump($content);
echo "<br/>";

function parseToArray($xpath,$class)
{
    $xpathquery="//span[@class='".$class."']";
    $elements = $xpath->query($xpathquery);

    if (!is_null($elements)) {  
        $resultarray=array();
        foreach ($elements as $element) {
            $nodes = $element->childNodes;
            foreach ($nodes as $node) {
              $resultarray[] = $node->nodeValue;
            }
        }
        return $resultarray;
    }
}

Live result: http://saji89.codepad.org/2TyOAibZ

Solution 2:

Try to look at PHP Simple HTML DOM Parser

It has brilliant syntax similar to jQuery so you can easily select any element you want by ID or class

// include/require the simple html dom parser file

$html_string = '
    <p class="Heading1-P">
        <span class="Heading1-H">Chapter 1</span>
    </p>
    <p class="Normal-P">
        <span class="Normal-H">This is chapter 1</span>
    </p>
    <p class="Heading1-P">
        <span class="Heading1-H">Chapter 2</span>
    </p>
    <p class="Normal-P">
        <span class="Normal-H">This is chapter 2</span>
    </p>
    <p class="Heading1-P">
        <span class="Heading1-H">Chapter 3</span>
    </p>
    <p class="Normal-P">
        <span class="Normal-H">This is chapter 3</span>
    </p>';
$html = str_get_html($html_string);
foreach($html->find('span') as $element) {
    if ($element->class === 'Heading1-H') {
        $heading[] = $element->innertext;
    }else if($element->class === 'Normal-H') {
        $content[] = $element->innertext;
    }
}

Solution 3:

One option for you is to use DOMDocument and DOMXPath. They do require a bit of a curve to learn, but once you do, you will be pretty happy with what you can achieve.

Read the following in php.net

http://php.net/manual/en/class.domdocument.php

http://php.net/manual/en/class.domxpath.php

Hope this helps.

Solution 4:

Here's an alternative way to parse the html using DiDOM which offers significantly better performance in terms of speed and memory footprint.

composer require imangazaliev/didom
<?php

use DiDom\Document;

require_once('vendor/autoload.php');

$html = <<<HTML
<p class="Heading1-P">
    <span class="Heading1-H">Chapter 1</span>
</p>
<p class="Normal-P">
    <span class="Normal-H">This is chapter 1</span>
</p>
<p class="Heading1-P">
    <span class="Heading1-H">Chapter 2</span>
</p>
<p class="Normal-P">
    <span class="Normal-H">This is chapter 2</span>
</p>
<p class="Heading1-P">
    <span class="Heading1-H">Chapter 3</span>
</p>
<p class="Normal-P">
    <span class="Normal-H">This is chapter 3</span>
</p>
HTML;

$document = new Document($html);

// find chapter headings
$elements = $document->find('.Heading1-H');

$headings = [];

foreach ($elements as $element) {
    $headings[] = $element->text();
}

// find chapter texts
$elements = $document->find('.Normal-H');

$chapters = [];

foreach ($elements as $element) {
    $chapters[] = $element->text();
}

echo("Headings\n");

foreach ($headings as $heading) {
    echo("- {$heading}\n");
}

echo("Chapter texts\n");

foreach ($chapters as $chapter) {
    echo("- {$chapter}\n");
}