PHP DOM getattribute manipulation

Question

i'm struggling to find an answer for the following... i suspect I don't really know what i'm asking for or how to ask it... let me describe:

I would like to grab some links from a page. I only want the links that have the following word as part of the URL: "advertid". Therefore and for example, the URL would be something like http://thisisanadvertis.com/questions/ask.

I've got this far

                <?php
// This is our starting point. Change this to whatever URL you want.
$start = "https://example.com";

function follow_links($url) {
    // Create a new instance of PHP's DOMDocument class.
    $doc = new DOMDocument();
    // Use file_get_contents() to download the page, pass the output of file_get_contents()
    // to PHP's DOMDocument class.
    @$doc->loadHTML(@file_get_contents($url));
    // Create an array of all of the links we find on the page. 
    $linklist = $doc->getElementsByTagName("a");
    // Loop through all of the links we find.
    foreach ($linklist as $link) {
        echo $link->getAttribute("href")."\n";
    }
}
// Begin the crawling process by crawling the starting link first.
follow_links($start);
        ?>

This returns all URLs on the page... which is OK. So to try and get the URLs i wanted, i tried a few things including trying to amend the getattribute part:

echo $link->getAttribute("href"."*advertid*")."\n";

I've tried a few things... but can't get what i want. Can someone point me in the right direction, i'm a bit stuck.

Many thanks in advance.

You want to filter some urls?

Felippe Duarte
– Felippe Duarte

2018-10-11 19:59:55 +00:00
Commented Oct 11, 2018 at 19:59 — Felippe Duarte
– Felippe Duarte, Commented Oct 11, 2018 at 19:59
Basically -- yes

GtDriver
– GtDriver

2018-10-11 20:01:31 +00:00
Commented Oct 11, 2018 at 20:01 — GtDriver
– GtDriver, Commented Oct 11, 2018 at 20:01

sietse85 · Accepted Answer · 2018-10-11 20:02:39Z

1

foreach ($linklist as $link) {
   if (strpos($link->getAttribute("href"), 'advertid') !== false) {
       echo $link->getAttribute("href")."\n";
   }
}

answered Oct 11, 2018 at 20:02

sietse85

1,5161 gold badge12 silver badges27 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

GtDriver Over a year ago

Just beaten to it ;). Thank you for this.

sietse85 Over a year ago

this was kinda funny the moment i posted my answer i saw the other answer which were almost identical haha.

Felippe Duarte · Accepted Answer · 2018-10-11 20:02:40Z

1

You can check if the href attribute has the info you want, with some logic, dependending on the case:

foreach ($linklist as $link) {
    if(strpos($link->getAttribute("href"), 'advertid') >= 0) {
        echo $link->getAttribute("href")."\n";
    }
}

answered Oct 11, 2018 at 20:02

Felippe Duarte

15.2k2 gold badges27 silver badges29 bronze badges

Comments

zkemppel · Accepted Answer · 2018-10-11 20:27:11Z

1

$links = []
foreach ($linklist as $link) {
    $href = $link->getAttribute("href");
    if (preg_match('/.*advertid.*/', $href)) {
        array_push($links, $href);
    }
}

edited Oct 11, 2018 at 20:27

answered Oct 11, 2018 at 20:08

zkemppel

2341 silver badge7 bronze badges

1 Comment

GtDriver Over a year ago

This is useful. I note the array_push function... i needed that also! Many thanks :)

Jimmy Surprenant · Accepted Answer · 2018-10-11 20:03:29Z

0

I would suggest you to use PHP function strpos

strpos takes at least two parameter, the first is the string you're searching in. The second parameter is what you're looking for in the first string.

strpos returns the position of the string if it's found, or false if it's not found.

So your loop would look something like :

foreach ($linklist as $link) {
    if( strpos($link->getAttribute("href"), 'advertid') !== false ){
       echo $link->getAttribute("href")."\n";
    }
}

answered Oct 11, 2018 at 20:03

Jimmy Surprenant

1637 bronze badges

3 Comments

GtDriver Over a year ago

Many thanks Jimmy -- this worked. I've now put each $link into an array. Am I correct in thinking that the array should now only contain the URLs I want (i.e., those with 'advertid' in them? I've tried print_r ($array)... but i can't see the URLs in the out put.

GtDriver Over a year ago

I think i'm populating my array incorrectly. I note zkempel below used the array_push function, which i will try :).

GtDriver Over a year ago

Like a charm :)

Collectives™ on Stack Overflow

PHP DOM getattribute manipulation

4 Answers 4

2 Comments

Comments

1 Comment

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

2 Comments

Comments

1 Comment

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related