Can't PHP screen scrape

[DrJohnSmitherson]

Hey guys! On my website you all helped me display the text from another website. When the source website changed, you all helped me fix it so it would work again. It's broken once again so I decided I would try to learn it on my own but I can't figure it out. Could someone post the code and then explain what's going on by any chance? :cry:

So this is the site and I would like to display the downloads from that webpage. I would like it to load the downloads everytime someone loads MY webpage so the downloads are always current.

https://addons.mozilla.org/en-US/firefox/addon/strike-49896/

Thanks again Neowinians!! :yes:

[sweetsam]

It is very easy using php oop.

$data = file_get_contents('https://addons.mozilla.org/en-US/firefox/addon/strike-49896/');

$html = new DOMDocument();

@$html->loadHTML($data);

foreach($html->getElementsByTagName('strong') as $strong):
        if ($strong->getAttribute('class') === 'downloads'):
                echo $strong->childNodes[0]->nodeValue;
        endif;
endforeach;

[DrJohnSmitherson]

<?php
$data = file_get_contents('https://addons.mozilla.org/en-US/firefox/addon/strike-49896/');

$html = new DOMDocument();

@$html->loadHTML($data);

foreach($html->getElementsByTagName('strong') as $strong):
        if ($strong->getAttribute('class') === 'downloads'):
                echo $strong->childNodes[0]->nodeValue;
        endif;
endforeach;
?>

I added this but it didn't work :(

http://firefox.thechillroom.com/strike.php

[AnthonySterling]

YQL can make this easier...

Check out %27"]this query.

<?php
try{
  $response = new SimpleXMLElement(
    "http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20html%20where%20url%3D%22https%3A%2F%2Faddons.mozilla.org%2Fen-US%2Ffirefox%2Faddon%2Fstrike-49896%2F%22%20and%0A%20%20%20%20%20%20xpath%3D'%2F%2Fstrong%5B%40class%20%3D%20%22downloads%22%5D    null,
    true
  );
}catch(Exception $e){
  $response = null;
}

$count = '0';

if(null !== $response && 1 === count($response->results)){
  $count = (string)$response->results->strong;
}

echo $count;

It's untested, so you may have to tweak.

[sweetsam]

Yeah I tested it after seeing your post and indeed it does not work. file_get_contents does not support https. There is some tweaks to get it to work but at this point it is not worth the effort. Anthony's approach is much better.

  On 04/02/2011 at 03:48, thatguyandrew1992 said:

<?php
$data = file_get_contents('https://addons.mozilla.org/en-US/firefox/addon/strike-49896/');

$html = new DOMDocument();

@$html->loadHTML($data);

foreach($html->getElementsByTagName('strong') as $strong):
        if ($strong->getAttribute('class') === 'downloads'):
                echo $strong->childNodes[0]->nodeValue;
        endif;
endforeach;
?>

I added this but it didn't work :(

http://firefox.thechillroom.com/strike.php

[DrJohnSmitherson]

  On 04/02/2011 at 11:54, AnthonySterling said:

YQL can make this easier...

Check out %27"]this query.

$count = '0';

It's untested, so you may have to tweak.

I appreciate your help very much. I tried it out. But that line is what defines the number that appears instead of what is from the mozilla site, and I'm not sure how to fix it :blush:

[sweetsam]

I tried what Anthony posted and it works perfectly and the output matches the number on Mozilla's website. You might wanna check the code and make sure there are not line breaks where there shouldn't be any.

[DrJohnSmitherson]

  On 04/02/2011 at 22:04, sweetsam said:

I tried what Anthony posted and it works perfectly and the output matches the number on Mozilla's website. You might wanna check the code and make sure there are not line breaks where there shouldn't be any.

You were right! Copying it from neowin caused some line breaks! Thanks for all the help guys!!! :D

[sweetsam]

I would recommend storing the data locally and updating it once a day. Do not load the data remotely every time your page loads because it might get you banned.

[DrJohnSmitherson]

  On 05/02/2011 at 02:40, sweetsam said:

I would recommend storing the data locally and updating it once a day. Do not load the data remotely every time your page loads because it might get you banned.

I see. I don't know how to do that though. :unsure:

[sweetsam]

Try this...

		$file = 'count.txt';

		if ( file_exists($file) and time() - filemtime($file) < 3600):
			$count = file_get_contents($file);
		else:
			try{
				$response = new SimpleXMLElement("http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20html%20where%20url%3D%22https%3A%2F%2Faddons.mozilla.org%2Fen-US%2Ffirefox%2Faddon%2Fstrike-49896%2F%22%20and%0A%20%20%20%20%20%20xpath%3D'%2F%2Fstrong%5B%40class%20%3D%20%22downloads%22%5Dnull, true);
			}catch(Exception $e){
				$response = null;
			}

			$count = '0';

			if(null !== $response && 1 === count($response->results)):
			  $count = (string)$response->results->strong;
			endif;

			file_put_contents($file, $count);
		endif;

		echo $count;

[DrJohnSmitherson]

  On 05/02/2011 at 17:23, sweetsam said:

Try this...

		$file = 'count.txt';

		if ( file_exists($file) and time() - filemtime($file) < 3600):
			$count = file_get_contents($file);
		else:
			try{
				$response = new SimpleXMLElement("http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20html%20where%20url%3D%22https%3A%2F%2Faddons.mozilla.org%2Fen-US%2Ffirefox%2Faddon%2Fstrike-49896%2F%22%20and%0A%20%20%20%20%20%20xpath%3D'%2F%2Fstrong%5B%40class%20%3D%20%22downloads%22%5Dnull, true);
			}catch(Exception $e){
				$response = null;
			}

			$count = '0';

			if(null !== $response && 1 === count($response->results)):
			  $count = (string)$response->results->strong;
			endif;

			file_put_contents($file, $count);
		endif;

		echo $count;

Now I would use the code for multiple pages on my website. Should I change count.txt to countstrike.txt. Then have countsky.txt and countroyalblue.txt etc on my other pages?

[sweetsam]

Don't need different file names as long as the data being stored is the same.

[DrJohnSmitherson]

  On 06/02/2011 at 01:17, sweetsam said:

Don't need different file names as long as the data being stored is the same.

Ok. In this case it will be different since my all themes have different downloads.

[AnthonySterling]

Elaborating on SweetSam's example, you could create two handy-dandy functions to help.

function get_stats($id){
  try{
    $response = new SimpleXMLElement(
      "http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20html%20where%20url%3D%22https%3A%2F%2Faddons.mozilla.org%2Fen-US%2Ffirefox%2Faddon%2F" . $id . "%2F%22%20and%0A%20%20%20%20%20%20xpath%3D'%2F%2Fstrong%5B%40class%20%3D%20%22downloads%22%5D'",
      null,
      true
    );
  }catch(Exception $e){
    $response = null;
  }

  $count = '0';

  if(null !== $response && 1 === count($response->results)){
    $count = (string)$response->results->strong;
  }

  return $count;
}

function get_cached_stats($id, $lifetime = 3600){
  $file = $id . '_stats_cache.txt';
  if(is_readable($file) && time() - filemtime($file) < (int)$lifetime){
    return file_get_contents($file);
  }
  $data = get_stats($id);
  file_put_contents($file, $data);
  return $data;
}

[DrJohnSmitherson]

Hmm interesting. Where do I insert the, id, I suppose, so it knows which addon page to go to?

[AnthonySterling]

<?php
echo get_cached_stats('strike-49896');