DOMDocument PHP web scraping

Question

I was wondering if there was any way to use dom to select elements that have dynamic tags. All of the tags start with link_(some id).

Example:

<tr id="link_111111">something in here...</tr>

<tr id="link_222222">something in here...</tr>

<tr id="link_333333">something in here...</tr>

<tr id="link_444444">something in here...</tr>

<tr id="link_555555">something in here...</tr>

I was wondering if I could grab all the tr's that have the id with link_ because I don't have the specific id's, they are random.

Answer 1

You can use an XPath expression to achieve this:

//tr[starts-with(@id, "link")]

Example:

$dom = new DOMDocument;
$dom->loadHTML($html);

$xpath = new DOMXPath($dom);
$nodes = $xpath->query('///tr[starts-with(@id, "link")]');

foreach ($nodes as $node) {
    // Do whatever
}

Demo

Answer 2

DOM way using some string functions ...

$dom = new DOMDocument;
$dom->loadHTML($html); $tagK = 'link_';
foreach ($dom->getElementsByTagName('tr') as $tag) {
    if (substr(strtolower($tag->getAttribute('id')),0,strlen($tagK))===$tagK) {
        echo $tag->getAttribute('id').PHP_EOL; 
    }
}

Demo

Answer 3

Or if you want to have more flexible way and easy to Web Scrape.. I suggest you take a look at https://github.com/fabpot/goutte which act as wrapper. that you can also used for clicking a link or submitting a form..

I made some tutorials using Goutte Class for Web Scraping.. Feel free to check it. http://iapdesign.com/webdev/laravel-4-webdev/superb-web-scraping-tutorials-using-laravel-4/