php - Simple HTML dom - elements between other elements - php

Question

I'm trying to write a php script to crawl a website and keep some elements in data base.
Here is my problem : A web page is written like this :
<h2>The title 1</h2>
<p class="one_class"> Some text </p>
<p> Some interesting text </p>
<h2>The title 2</h2>
<p class="one_class"> Some text </p>
<p> Some interesting text </p>
<p class="one_class"> Some different text </p>
<p> Some other interesting text </p>
<h2>The title 3</h2>
<p class="one_class"> Some text </p>
<p> Some interesting text </p>
I want to get only the h2 and p with interesting text, not the p class="one_class".
I tried this php code :
<?php
$numberP = 0;
foreach($html->find('p') as $p)
{
$pIsOneClass = PIsOneClass($html, $p);
if($pIsOneClass == false)
{
echo $p->outertext;
$h2 = $html->find("h2", $numberP);
echo $h2->outertext;
$numberP++;
}
}
?>
the function PIsOneClass($html, $p) is :
<?php
function PIsOneClass($html, $p)
{
foreach($html->find("p.one_class") as $p_one_class)
{
if($p == $p_one_class)
{
return true;
}
}
return false;
}
?>
It doesn't work, i understand why but i don't know how to resolve it.
How can we say "I want every p without class who are between two h2 ?"
Thx a lot !

Answer 1

This task is easier with XPath, since you're scraping more than one element and you want to keep the source in order. You can use PHP's DOM library, which includes DOMXPath, to find and filter the elements you want:
$html = '<h2>The title 1</h2>
<p class="one_class"> Some text </p>
<p> Some interesting text </p>
<h2>The title 2</h2>
<p class="one_class"> Some text </p>
<p> Some interesting text </p>
<p class="one_class"> Some different text </p>
<p> Some other interesting text </p>
<h2>The title 3</h2>
<p class="one_class"> Some text </p>
<p> Some interesting text </p>';
# create a new DOM document and load the html
$dom = new DOMDocument;
$dom->loadHTML($html);
# create a new DOMXPath object
$xp = new DOMXPath($dom);
# search for all h2 elements and all p elements that do not have the class 'one_class'
$interest = $xp->query('//h2 | //p[not(#class="one_class")]');
# iterate through the array of search results (h2 and p elements), printing out node
# names and values
foreach ($interest as $i) {
echo "node " . $i->nodeName . ", value: " . $i->nodeValue . PHP_EOL;
}
Output:
node h2, value: The title 1
node p, value: Some interesting text
node h2, value: The title 2
node p, value: Some interesting text
node p, value: Some other interesting text
node h2, value: The title 3
node p, value: Some interesting text
As you can see, the source text stays in order, and it's easy to eliminate the nodes you don't want.

Answer 2

From the simpleHTML dom manual
[attribute=value]
Matches elements that have the specified attribute with a certain value.
or
[!attribute]
Matches elements that don't have the specified attribute.