Initialization
To instantiate a new Tracker instance we need to make sure the Snowplow Tracker classes are available.
Include these class aliases in your project:
use Snowplow\Tracker\Tracker;
use Snowplow\Tracker\Subject;
use Snowplow\Tracker\Emitters\SyncEmitter;
We can now create our Emitter, Subject and Tracker objects.
Creating a Tracker
The most basic Tracker instance will only require you to provide an Emitter and the data Subject for which the Tracker will log events.
$emitter = new SyncEmitter($collector_uri, "http", "POST", 10, false);
$subject = new Subject();
$tracker = new Tracker($emitter, $subject);
Other Tracker arguments:
| Argument Name | Description | Required? | Default |
|---|---|---|---|
emitters | The emitter to which events are sent | Yes | None |
subject | The user being tracked | Yes | Subject() |
namespace | The name of the tracker instance | No | None |
app_id | The application ID | No | None |
encode_base64 | Whether to enable base 64 encoding | No | True |
Another example using all of the allowed arguments:
$tracker = new Tracker($emitter, $subject, "cf", "cf29ea", true);
emitters
This can be either a single emitter or an array of emitters. The tracker will send events to all of these emitters, which will, in turn, send them on to a collector.
$emitter1 = new SyncEmitter($collector_uri);
$emitter2 = new CurlEmitter($collector_uri, false, "GET", 2);
$emitter_array = array($emitter1, $emitter2);
// Tracker Init
$subject = new Subject();
$tracker1 = new Tracker($emitter1, $subject); # Single Emitter
$tracker2 = new Tracker($emitter_array, $subject); # Array of Emitters
subject
The user which the Tracker will track. This will give your events user-specific data such as timezone and language. You change the subject of your tracker at any time by calling updateSubject($new_subject_object). All events sent from this Tracker will now have the new subject information attached.
namespace
If provided, the namespace argument will be attached to every event fired by the new tracker. This allows you to later identify which tracker fired which event if you have multiple trackers running.
app_id
The app_id argument lets you set the application ID to any string.
encode_base64
By default, unstructured events and custom contexts are encoded into Base64 to ensure that no data is lost or corrupted. You can turn encoding on or off using the encode_base64 argument.