Reading Google Analytics data from PHP

Google Analytics has become a important part of any web sites traffic analysis strategy. And with the release of the Analytics API people have been able to create custom reports and mashups for their organizations. Although no standard library is available from Google for PHP, some small and easy interfaces are available out there. In this post we will see how to access Google Analytics data using PHP using the GAPI library.

Installing the GAPI class

The following code uses the GAPI – Google Analytics API PHP Interface to help us access the Analytics data. So before proceeding you need to download the class file from the GAPI home.

Dimensions & Metrics

Before we start a small primer on Google Analytics Dimensions & Metrics will be helpful.

What is a dimension?
Dimensions are things like browser and country, browser versions, landing and exit pages, the URL of a page, and the source website a visitor has come from.
Google Analytics uses the following 5 main marketing dimensions for analysis:

* Source
* Medium
* Term
* Content
* Campaign

What is a metric?
Metrics are the quantitative measure of a dimension for specific data types, such as counts of new visitors, page views, unique page views etc.

Getting the Google Analytics data

Now that we have seen what Dimensions & Metrics are we will proceed with an example. In this example we will fetch the ‘source’ dimension, which shows the source website the visitor is coming from and the ‘visits’ metric. This tells us how many visitors are coming from a particular source to our site.

require 'gapi-1.3/gapi.class.php';

/* Set your Google Analytics credentials */
define('ga_account'     ,'YOUR ANALYTICS EMAIL');
define('ga_password'    ,'YOUR ANALYTICS PASSWORD');
define('ga_profile_id'  ,'ANALYTICS SITE PROFILE ID');

$ga = new gapi(ga_account,ga_password);

/* We are using the 'source' dimension and the 'visits' metrics */
$dimensions = array('source');
$metrics    = array('visits');

/* We will sort the result be desending order of visits, 
    and hence the '-' sign before the 'visits' string */
$ga->requestReportData(ga_profile_id, $dimensions, $metrics,'-visits');

$gaResults = $ga->getResults();

$i=1;

foreach($gaResults as $result)
{
    printf("%-4d %-40s %5d\n",
           $i++,
           $result->getSource(),
           $result->getVisits());
}

echo "\n-----------------------------------------\n";
echo "Total Results : {$ga->getTotalResults()}";    

?>

Below I’ve listed the top ten results of the output.

No.  Source                                   Visits
------------------------------------------------------
1    google                                   10549
2    (direct)                                  1484
3    stumbleupon.com                           1338
4    webintenta.com                             159
5    bing                                       142
6    yahoo                                      115
7    feedburner                                  97
8    phpdeveloper.org                            70
9    t3n.de                                      64
10   clearspace.openqa.org                       43

As you can see the main method in the class is the ‘requestReportData()’, which has the following structure:

function requestReportData($report_id,      
                           $dimensions, 
                           $metrics, 
                           $sort_metric=null, 
                           $filter=null, 
                           $start_date=null, 
                           $end_date=null, 
                           $start_index=1, 
                           $max_results=30)   

You can get the Dimension and Metric result by prefixing ‘get’ to the dimension or metric name. For e.g, if you metric name is ‘region’, you can get the result by using:

$result->getRegion();

Although I have only provided a single Dimension and Metric in the example code, the $dimensions and $metrics parameter can take multiple parameters as shown below:

$dimensions = array('source', 'region');
$metrics    = array('visits');

Bear in mind to specify a valid ‘dimension-metric’ combination as given in the API Docs. Specifying an invalid combination will return 0 results.

The output after adding the ‘region’ dimension is shown below.

No. Source     Region               Visits
-----------------------------------------
1   google     (not set)              965
2   google     England                796
3   google     California             650
4   google     Maharashtra            343
5   google     Karnataka              340
6   google     Tamil Nadu             295
7   google     New York               225
8   google     Andhra Pradesh         189
9   google     Texas                  172
10  google     Ontario                165

Modifying the amount of results returned

By default the class returns the first 30 results, although the raw Google API returns 1000 results by default. You can increase the same by changing the $max_results parameter. Google Analytics returns a maximum of 10,000 results, even if you set the $max_results parameter above 10,000. To get the results above that limit you need to set the $start_index parameter to 10,000, which will then get the results starting at 10,000.

$ga->requestReportData(ga_profile_id,
                       $dimensions,
                       $metrics,
                       '-visits', // Sort by 'visits' in descending order
                       '','','', // We are not using this paras yet
                       1,  // Start Index
                       500 // Max results
                       );

You can get the total number of results by using the getTotalResults() method. This can be helpful in pagination.

$ga->getTotalResults();

Setting the Google Analytics report period

By default the class returns the data for the last 1 month from today if no report period is specified. You can specify the report period as below. The date format is in the form ‘YYYY-MM-DD’.

$ga->requestReportData(ga_profile_id,
                       $dimensions,
                       $metrics,
                       '-visits', // Sort by 'visits' in descending order
                       '',
                       '2009-10-01', // Start Date
                       '2009-12-31', // End Date
                       1,  // Start Index
                       500 // Max results
                       );

Filtering the data

You can further filter the results using the $filter parameter. Filtering is a little tricky, so be sure to read the Google documentation.

$filter = 'country == United States';

$ga->requestReportData(ga_profile_id,
                       $dimensions,
                       $metrics,
                       '-visits', // Sort by 'visits' in descending order
                       $filter, // Filter the data
                       '2009-10-01', // Start Date
                       '2009-12-31', // End Date
                       1,  // Start Index
                       500 // Max results
                       );

You can also combine various options:

$filter = 'country == United States && visitorType == New Visitor';
// OR
$filter = 'country == United States &&
           visitorType == New Visitor &&
           browser == Firefox';

Getting a list of your Google Analytics Accounts

Most users have more than one profiles in their Analytics account. You can easily get a list of all your accounts (sitename – profileid) with the following code.

require 'gapi-1.3/gapi.class.php';

/* Set your Google Analytics credentials */
define('ga_account'     ,'YOUR ANALYTICS EMAIL');
define('ga_password'    ,'YOUR ANALYTICS PASSWORD');

$ga = new gapi(ga_account,ga_password);

$gaResult = $ga->requestAccountData();

foreach($gaResult as $result)
{
  printf("%-30s %15d\n", $result, $result->getProfileId());
}

?>

With this we conclude this post. It will be quite helpful if you go over the below references if you are unfamiliar with the Google Analytics API.

Update

Webresourcesdepot features a nifty little application using the above to dispay the Google pageviews in a Feed-burner style chicklet display.

References:
a. Google Analytics Data API – Data Feed
b. Dimensions & Metrics Reference
c. Filters