regex to match a class element - GoFuckYourself.com

fris · 03-08-2012, 03:42 PM

im looking to match a h1 tag with a class, but also match after that class so

<h1 class="video-title one two clearfloat">get this</h1>

/<h1 class="video-title .*?\">(.*?)<\/h1>/

is this correct?

nm_ · 03-08-2012, 04:30 PM

i suck at remembering regex, so i always use dom->xpath queries instead. you could find the tag with a query something like this:

<?php

$dom = new DOMDocument();

$dom->loadHTML(HTMLHERE);

$xpath = new DOMXpath($dom);

$selectH1 = $xpath->query('//h1[@class="classnamehere"]');

?>

just came up with that right now, so dunno if that's the exact syntax, but i prefer traversing html w/ dom rather than regex

this is a good xpath query guide: http://www.earthinfo.org/xpaths-with-php-by-example/

Barry-xlovecam · 03-08-2012, 05:01 PM

\"video-title

Why · 03-08-2012, 05:43 PM

i know regex well enough to know thats not correct, but i dont know regex well enough to help you either.

sorry

raymor · 03-08-2012, 06:19 PM

Quote:

Originally Posted by fris

im looking to match a h1 tag with a class, but also match after that class so

<h1 class="video-title one two clearfloat">get this</h1>

/<h1 class="video-title .*?\">(.*?)<\/h1>/

is this correct?

You probably should be using a parser because your regexes and such are going to get out of hand as the project grows. That said, the .* will include > so you need a class there and the ? is meaningless given the * . So you're looking at something like:

/<h1 class="video-title([^>]*)\">([^<]*)<\/h1>/

Brujah · 03-08-2012, 08:11 PM

Like post #2 I prefer to use DOM for this type thing but something else I tend to do is use negatives in my regex so like this where $html contains the html/string:

Code:

if ( preg_match( '/<h1 class="video-title[^"]+">([^<]+)/', $html, $m ) )
{
        // var_dump($m);
        $h1 = $m[1];
}

edit: Ah I see ray had a similar thought.

fris · 03-08-2012, 08:22 PM

Quote:

Originally Posted by raymor

You probably should be using a parser because your regexes and such are going to get out of hand as the project grows. That said, the .* will include > so you need a class there and the ? is meaningless given the * . So you're looking at something like:

/<h1 class="video-title([^>]*)\">([^<]*)<\/h1>/

ya its only one regex in the script.

Brujah · 03-08-2012, 08:26 PM

I didn't even think to test fris' regex, but it works in this example too

Brujah · 03-08-2012, 08:33 PM

I want to expand on #2 post, so you can see a working example.

Code:

$html = '<h1 class="video-title one two clearfloat">get this</h1>';

$dom = new DOMDocument();

$dom->loadHTML( $html );

$xpath = new DOMXpath( $dom );

$h1 = $xpath->query( '//h1[contains(@class,"video-title")]' );

var_dump( $h1->item(0)->nodeValue );

DOM is so much better for parsing/scraping once you figure out how to use xpath queries. I had to use "contains(@class,"video-title")" in the above query because the class actually contains more than just 'video-title'

fris · 03-09-2012, 09:25 AM

Quote:

Originally Posted by Brujah

I want to expand on #2 post, so you can see a working example.

Code:

$html = '<h1 class="video-title one two clearfloat">get this</h1>';

$dom = new DOMDocument();

$dom->loadHTML( $html );

$xpath = new DOMXpath( $dom );

$h1 = $xpath->query( '//h1[contains(@class,"video-title")]' );

var_dump( $h1->item(0)->nodeValue );

DOM is so much better for parsing/scraping once you figure out how to use xpath queries. I had to use "contains(@class,"video-title")" in the above query because the class actually contains more than just 'video-title'

i actually timed it, the preg match is faster

Brujah · 03-09-2012, 11:56 AM

Quote:

Originally Posted by fris

i actually timed it, the preg match is faster

I can believe it, the DOM method does a lot more but is definitely overkill for just a simple one-off regex.

fris · 03-09-2012, 02:21 PM

ya only 1 regex was needed

Mr Cheeks · 03-09-2012, 02:37 PM

also try http://www.rubular.com/

mikke · 03-09-2012, 03:19 PM

Quote:

/<h1 class="video-title\s+(.*?)">(.*?)<\/h1>/i

try this one..

Brujah · 03-09-2012, 03:38 PM

These regex examples also rely on video-title to be the first class immediately after the quote mark, the DOM example is smart enough that it doesn't matter where video-title is located in the class order.

raymor · 03-09-2012, 03:55 PM

Quote:

Originally Posted by mikke

/<h1 class="video-title\s+(.*?)">(.*?)<\/h1>/i

try this one..

See my post for four reasons that's wrong.

fris · 03-09-2012, 04:12 PM

Quote:

Originally Posted by Brujah

These regex examples also rely on video-title to be the first class immediately after the quote mark, the DOM example is smart enough that it doesn't matter where video-title is located in the class order.

ya it is the first one

fris · 03-10-2012, 08:22 AM

Quote:

Originally Posted by raymor

See my post for four reasons that's wrong.

i used this one, it works correctly in php.

fris · 03-10-2012, 08:28 AM

Code:

<?php

$html = '<h1 class="video-title one two clearfloat">get this</h1>';

$raymor_regex = '/<h1 class="video-title([^>]*)\">([^<]*)<\/h1>/';
$brujah_regex = '/<h1 class="video-title[^"]+">([^<]+)/';
$mikke_regex = '/<h1 class="video-title\s+(.*?)">(.*?)<\/h1>/i';

preg_match($raymor_regex,$html,$raymor);
preg_match($brujah_regex,$html,$brujah);
preg_match($mikke_regex,$html,$mikke);

echo "raymor \n\n";
print_r($raymor);

echo "brujah \n\n";
print_r($brujah);

echo "mikke \n\n";
print_r($mikke);

these are the results

Code:

raymor

Array
(
    [0] => <h1 class="video-title one two clearfloat">get this</h1>
    [1] =>  one two clearfloat
    [2] => get this
)
brujah

Array
(
    [0] => <h1 class="video-title one two clearfloat">get this
    [1] => get this
)
mikke

Array
(
    [0] => <h1 class="video-title one two clearfloat">get this</h1>
    [1] => one two clearfloat
    [2] => get this
)

fris · 03-10-2012, 08:32 AM

modified brujah's with ending </h1>

Code:

/<h1 class="video-title[^"]+">([^<]+)<\/h1>/

gets 2 results, the orig, and the text between

Code:

Array
(
    [0] => <h1 class="video-title one two clearfloat">get this</h1>
    [1] => get this
)

03-08-2012, 03:42 PM	#1
fris Too lazy to set a custom title Industry Role: Join Date: Aug 2002 Posts: 55,372	regex to match a class element im looking to match a h1 tag with a class, but also match after that class so <h1 class="video-title one two clearfloat">get this</h1> /<h1 class="video-title .?\">(.?)<\/h1>/ is this correct? __________________ Since 1999: 69 Adult Industry awards for Best Hosting Company and professional excellence. WP Stuff

03-08-2012, 08:11 PM	#6
Brujah Beer Money Baron Industry Role: Join Date: Jan 2001 Location: brujah / gmail Posts: 22,157	Like post #2 I prefer to use DOM for this type thing but something else I tend to do is use negatives in my regex so like this where $html contains the html/string: Code: if ( preg_match( '/<h1 class="video-title[^"]+">([^<]+)/', $html, $m ) ) { // var_dump($m); $h1 = $m[1]; } edit: Ah I see ray had a similar thought. __________________ Free Premium Domain Lists and Tools at Clickmojo.com For Sale: Obscenity.com Last edited by Brujah; 03-08-2012 at 08:12 PM..

03-08-2012, 08:26 PM	#8
Brujah Beer Money Baron Industry Role: Join Date: Jan 2001 Location: brujah / gmail Posts: 22,157	I didn't even think to test fris' regex, but it works in this example too __________________ Free Premium Domain Lists and Tools at Clickmojo.com For Sale: Obscenity.com

03-08-2012, 08:33 PM	#9
Brujah Beer Money Baron Industry Role: Join Date: Jan 2001 Location: brujah / gmail Posts: 22,157	I want to expand on #2 post, so you can see a working example. Code: $html = '<h1 class="video-title one two clearfloat">get this</h1>'; $dom = new DOMDocument(); $dom->loadHTML( $html ); $xpath = new DOMXpath( $dom ); $h1 = $xpath->query( '//h1[contains(@class,"video-title")]' ); var_dump( $h1->item(0)->nodeValue ); DOM is so much better for parsing/scraping once you figure out how to use xpath queries. I had to use "contains(@class,"video-title")" in the above query because the class actually contains more than just 'video-title' __________________ Free Premium Domain Lists and Tools at Clickmojo.com For Sale: Obscenity.com

03-09-2012, 02:21 PM	#12
fris Too lazy to set a custom title Industry Role: Join Date: Aug 2002 Posts: 55,372	ya only 1 regex was needed __________________ Since 1999: 69 Adult Industry awards for Best Hosting Company and professional excellence. WP Stuff

03-08-2012, 04:30 PM	#2
nm_ Confirmed User Industry Role: Join Date: May 2011 Location: San Diego Posts: 328	i suck at remembering regex, so i always use dom->xpath queries instead. you could find the tag with a query something like this: <?php $dom = new DOMDocument(); $dom->loadHTML(HTMLHERE); $xpath = new DOMXpath($dom); $selectH1 = $xpath->query('//h1[@class="classnamehere"]'); ?> just came up with that right now, so dunno if that's the exact syntax, but i prefer traversing html w/ dom rather than regex this is a good xpath query guide: http://www.earthinfo.org/xpaths-with-php-by-example/

03-08-2012, 05:01 PM	#3
Barry-xlovecam It's 42 Industry Role: Join Date: Jun 2010 Location: Global Posts: 18,083	\"video-title

03-08-2012, 05:43 PM	#4
Why MFBA Industry Role: Join Date: Mar 2003 Location: PNW Posts: 7,230	i know regex well enough to know thats not correct, but i dont know regex well enough to help you either. sorry

03-09-2012, 02:37 PM	#13
Mr Cheeks Confirmed User Join Date: Apr 2002 Posts: 901	also try http://www.rubular.com/

03-09-2012, 03:38 PM	#15
Brujah Beer Money Baron Industry Role: Join Date: Jan 2001 Location: brujah / gmail Posts: 22,157	These regex examples also rely on video-title to be the first class immediately after the quote mark, the DOM example is smart enough that it doesn't matter where video-title is located in the class order. __________________ Free Premium Domain Lists and Tools at Clickmojo.com For Sale: Obscenity.com

03-10-2012, 08:32 AM	#20
fris Too lazy to set a custom title Industry Role: Join Date: Aug 2002 Posts: 55,372	modified brujah's with ending </h1> Code: /<h1 class="video-title[^"]+">([^<]+)<\/h1>/ gets 2 results, the orig, and the text between Code: Array ( [0] => <h1 class="video-title one two clearfloat">get this</h1> [1] => get this ) __________________ Since 1999: 69 Adult Industry awards for Best Hosting Company and professional excellence. WP Stuff