Problems extracing keyword from GA cookie

PHP
1

Morning all - I’m hoping someone might be able to help me with a function problem I’m having.

I’m trying to extract keyword information from the Google Analytics cookie with the following code:


<?
function parse_ga_cookie($cookie)

{

    $values = sscanf($cookie, '%d.%d.%d.%d.utmcsr=%[^|]|utmccn=%[^|]|utmcmd=%[^|]|utmctr=%[^|]');

    if (count($values) !== 8) {

        // return false; trigger_error(...); ... or whatever you like

        throw new InvalidArgumentException("Cookie value '$cookie' does not conform to the __utmz pattern");

    }

    $keys = array('domain', 'timestamp', 'visits', 'sources', 'campaign', 'source', 'medium', 'keyword');

    return array_combine($keys, $values);

}

// Cookie info
$keyword=print_r(parse_ga_cookie($_COOKIE['__utmz']));
?>

Now unfortunately, the $keyword variable is coming up empty all the time and I was hoping someone might be able to tell me where I’m going wrong.

Having looked through it, I"m wondering if the problem lies with the sscanf() function which parses a string based on placeholders. However, “%[^|]” looks more like a regular expression which isn’t valid in sscaf()

If that’s the case, how should I go about changing this? Is it just as simple as replacing sscanf() with preg_match()?

Thanks a lot for your help!

2

$keyword will contain the return value from print_r() which will be TRUE.

Those %[^|] are not regular expressions. They are basic wildcard patterns (in this case, “some non-pipe characters”), a perhaps small but important distinction.

Finally, a few questions. What does the print_r() actually output, I’m guessing the expected array? Why would you expect a function that returns an array to return a single value (the keywords)?

3

Sorry, you’re right - I posted the wrong snippet. I included the print_r() variable like that, just to make sure that the array was being formed correctly.

I guess I was originally concerned that nothing was coming through in the keyword section of the array, which was I wasked the question about regular expressions. The “%d” seems to indicate I was looking for an integer, where as the keyword part of the array will obviously be containing a string.

If you think it still looks ok though, I’ll continue to test.

4

Show us some examples of the cookie values that cause the error, and the output from the function.

5

Thanks for taking the time to look at this Salathe - it’s much appreciated.

Here’s a screenshot of the populated array the last time that I ran the script.

As you can see, the integers have populated without a problem, but the strings aren’t there, which is why I thought there might have been a problem with the sscanf() function.

6

Show us some examples of the cookie values that cause the error… (:

7

Sorry Salathe,

Here you go:

217416581.1296138642.1.1.utmccn=(organic)|utmcsr=google|utmctr=best+ereader+reviews|utmcmd=organic
8

Ahh, the utm* items are in a different order than required for the sscanf() to read them. A regex, or more involved approach, might be necessary.

9

That would make sense.

When you speak of regex, if I’m only looking for one value (in this case the utmctr value) would it be possible to set up a simple pattern match which would simply look for the string ‘utmctr=’ and then assign everything from there up to the pipe in a variable?

Thanks,

10

Sure, why don’t you have a go while I finish up here at work. :slight_smile:

11

I think I managed to get it sorted out last night - it’s not quite as elegant as the previous code, but it seems to solve the problems that were being caused.

Thanks for highlighting the issues Salathe, and for your help!