如何在PHP中抓取JavaScript值

Question

I'm new to PHP and coding in general and I can't figure this out. I'm trying to get the number of kills from this profile page .

At the moment, the string I am trying to get is:

29362

When I view the page source, this number is nowhere to be seen.

When I use inspect element, however, I find:

<td class="num">29362</td>

How can I get the content shown in inspect element instead of the content shown by viewing the page source?

Answer 1

In using a tool like Firebug for Firefox, or the inspector for Safari and Chrome, you can see that at page load a series of AJAX requests are made for data. Though I didn't dig through all of the data returned by those requests, I do see the data you're looking for in at least one of them:

http://uberstrike.com/profile/all_stats/631163 

So at page load JavaScript makes a series of AJAX requests back to the server to get all the data, then it manipulates the DOM to insert it all into the view.

If you wanted, your PHP could directly request the URL I pasted above and json_decode the response. This would produce a data structure for you to use which includes that number in the kills_all_time property.

Quick and dirty example:

<?php
$data_url = 'http://uberstrike.com/profile/all_stats/631163';

$serialized_data = file_get_contents($data_url);

$data = json_decode($serialized_data, true);

var_dump($data['kills_all_time']);

Answer 2

I looked and it looks like there is no API currently, so your best method will be to do an inter-web-server http request. Get the page you want and then it is a lot of string math from there.

I would recommend using string search to find <td class="name">Kills</td> and the kills row will appear right after it. From there its simply extracting the number using string math.

Answer 3

To add to what JAAulde has explained, it seems like there is a method to these AJAX requests. And they are all based on the profile ID that can be found at the end of the URL:

http://uberstrike.com/public_profile/631163

Then in the Safari debugger (which is what I am using) you can see these XHR ( XMLHttpRequest ) requests which are directly connected to API calls:

Then looking at the data in them shows some really nicely formatted JSON. Great! No scraping! So just go through these URLs to see what you can see:

http://uberstrike.com/profile/items

http://uberstrike.com/profile/user_info/631163

http://uberstrike.com/profile/user_loadout/631163

http://uberstrike.com/profile/all_stats/631163

And looking at the all_stats endpoint shows:

"kills_all_time":29362,

Nice!

So now let's use some PHP json_decode ing like this:

// Set the URL to the data.
$url = 'http://uberstrike.com/profile/all_stats/631163';

// Get the contenst of the URL via file_get_contents.
$all_stats_json = file_get_contents($url);

// Decode the JSON string with the 'true' optionso we get any array.
$all_stats_json_decoded = json_decode($all_stats_json, true);

// Dump the results for testing.
echo '<pre>';
print_r($all_stats_json_decoded);
echo '</pre>';

Which will dump an array like this:

Array
(
    [headshots_record] => 24
    [nutshots_record] => 33
    [damage_dealt_record] => 6710
    [damage_received_record] => 31073
    [kills_record] => 50
    [smackdowns_record] => 45
    [headshots_all_time] => 4299
    [nutshots_all_time] => 1925
    [kills_all_time] => 29362
    [deaths_all_time] => 16491
    …

Now to get kills_all_time just do this:

// Return the 'kills_all_time'.
echo $all_stats_json_decoded['kills_all_time'];

Which gives us:

29362