Subjects

The Subject object lets you send any additional information about your application’s environment, current user etc to Snowplow.

To create a new subject:

$subject = new Subject();

By default the subject has one piece information in it already, the platform [“p” => “srv”].

The Subject class contains a variety of ‘set’ methods to attach extra data to your event.

• setPlatform
• setUserId
• setScreenRes
• setViewport
• setColorDepth
• setTimezone
• setLanguage
• setIpAddress
• setUseragent
• setNetworkUserId
• setDomainUserId

These set methods can be called either directly onto a subject object:

$subject = new Subject();
$subject->setPlatform("tv");

Or they can be called through the tracker object:

$tracker->returnSubject()->setPlatform("tv");

setPlatform

The default platform is “srv”. You can change the platform of the subject by calling:

$subject->setPlatform($platform);

For example:

$subject->setPlatform("tv") # Running on a Connected TV

For a full list of supported platforms, please see the Snowplow Tracker Protocol.

setUserId

You can set the user ID to any string:

$subject->setUserId($id);

Example:

$subject->setUserId("jbeem");

setScreenResolution

If your PHP code has access to the device’s screen resolution, then you can pass this in to Snowplow too:

$subject->setScreenResolution($width, $height);

Both numbers should be positive integers; note the order is width followed by height. Example:

$subject->setScreenResolution(1366, 768);

setViewport

If your PHP code has access to the viewport dimensions, then you can pass this in to Snowplow too:

$subject->setViewport($width, $height);

Both numbers should be positive integers; note the order is width followed by height. Example:

$subject->setViewport(300, 200);

setColorDepth

If your PHP code has access to the bit depth of the device’s color palette for displaying images, then you can pass this in to Snowplow too:

$subject->setColorDepth($depth);

The number should be a positive integer, in bits per pixel. Example:

$subject->setColorDepth(32);

setTimezone

This method lets you pass a user’s timezone in to Snowplow:

$subject->setTimezone($timezone);

The timezone should be a string:

$subject->setTimezone("Europe/London");

setLanguage

This method lets you pass a user’s language in to Snowplow:

$subject->setLanguage($language);

The language should be a string:

$subject->setLanguage('en');

setIpAddress

This method lets you pass a user’s IP Address in to Snowplow:

$subject->setIpAddress($ip);

The IP Address should be a string:

$subject->setIpAddress('127.0.0.1');

setUseragent

This method lets you pass a useragent in to Snowplow:

$subject->setUseragent($useragent);

The useragent should be a string:

$subject->setUseragent('Agent Smith');

setNetworkUserId

This method lets you pass a Network User ID in to Snowplow:

$subject->setNetworkUserId($networkUserId);

The network user id should be a string:

$subject->setNetworkUserId("network-id");

setDomainUserId

This method lets you pass a Domain User ID in to Snowplow:

$subject->setDomainUserId($domainUserId);

The domain user id should be a string:

$subject->setDomainUserId("domain-id");