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Initialization and configuration

The package provides a single method to initialize and configure a new tracker, the Snowplow.createTracker method. It accepts configuration parameters for the tracker and returns a SnowplowTracker instance.

SnowplowTracker tracker = await Snowplow.createTracker(
namespace: 'ns1',
endpoint: 'http://...',
trackerConfig: const TrackerConfiguration(...),
gdprConfig: const GdprConfiguration(...),
subjectConfig: const SubjectConfiguration(...));

The method returns a SnowplowTracker instance. This can be later used for tracking events, or accessing tracker properties. However, all methods provided by the SnowplowTracker instance are also available as static functions in the Snowplow class but they require passing the tracker namespace as string.

The only required attributes of the Snowplow.createTracker method are namespace used to identify the tracker, and the Snowplow collector endpoint. Additionally, one can configure the HTTP method to be used when sending events to the collector, as well as a custom POST path, and provide configuration by instantiating classes for TrackerConfiguration, SubjectConfiguration, or GdprConfiguration. By default, events are sent by POST. The following arguments are accepted by the Snowplow.createTracker method:

namespaceStringTracker namespace to identify the tracker.
endpointStringURI for the Snowplow collector endpoint.
methodMethod?HTTP method to use: Method.get or ( is default).
customPostPathString?Custom POST path.
requestHeadersMap<String, String>?Map of custom HTTP headers to add to requests to the collector.
trackerConfigTrackerConfiguration?Configuration of the tracker and the core tracker properties.
gdprConfigGdprConfiguration?Determines the GDPR context that will be attached to all events sent by the tracker.
subjectConfigSubjectConfiguration?Subject information about tracked user and device that is added to events.
emitterConfigEmitterConfiguration?Configuration for how the events are sent.

The ability to set customPostPath was added in v0.2.0. Setting a custom POST path can be useful in avoiding adblockers; it replaces the default "com.snowplowanalytics/snowplow/tp2". Your event collector must also be configured to accept the custom path.


The EmitterConfiguration class was added in v0.3.0.

Configuration of tracker properties: TrackerConfiguration

TrackerConfiguration provides options to configure properties and features of the tracker. In addition to setting the app identifier and device platform, the configuration enables turning several automatic context entities on and off.

appIdString?Identifier of the app.null on Web, bundle identifier on iOS/Android
devicePlatformDevicePlatform?The device platform the tracker runs on. Available options are provided by the DevicePlatform enum."web" on Web, "mob" on iOS/Android
base64Encodingbool?Indicates whether payload JSON data should be base64 encoded.true
platformContextbool?Indicates whether platform (mobile) entity should be attached to tracked events.true
geoLocationContextbool?Indicates whether geo-location entity should be attached to tracked events.false
sessionContextbool?Indicates whether session entity should be attached to tracked events.true
webPageContextbool?Indicates whether a context entity about current web page should be attached to tracked events.true
screenContextbool?Indicates whether screen entity should be attached to tracked events.true
applicationContextbool?Indicates whether application entity should be attached to tracked events.true
webActivityTrackingWebActivityTracking?Enables activity tracking using page views and pings on the Web.true
userAnonymisationbool?Anonymizes certain user identifiers.false
lifecycleAutotrackingbool?Indicates whether the lifecycle entity and foreground and background events should be autotracked.true
screenEngagementAutotrackingbool?Indicates whether to enable tracking of the screen end event and the screen summary context entity.true
platformContextPropertiesPlatformContextProperties?Overrides for the values for properties of the platform context entity.null

The ability to enable userAnonymisation, or the screen and application context entities, was added in v0.3.0.


The ability to enable lifecycleAutotracking was added in v0.5.0.

The optional WebActivityTracking property configures page tracking on Web. Initializing the configuration will inform SnowplowObserver observers (see section on auto-tracking in "Tracking events") to auto track PageViewEvent events instead of ScreenView events on navigation changes. Further, setting the minimumVisitLength and heartbeatDelay properties of the WebActivityTracking instance will enable activity tracking using 'page ping' events on Web.

Activity tracking monitors whether a user continues to engage with a page over time, and record how they digest content on the page over time. That is accomplished using 'page ping' events. If activity tracking is enabled, the web page is monitored to see if a user is engaging with it. (E.g. is the tab in focus, does the mouse move over the page, does the user scroll etc.) If any of these things occur in a set period of time (minimumVisitLength seconds from page load and every heartbeatDelay seconds after that), a page ping event fires, and records the maximum scroll left / right and up / down in the last ping period. If there is no activity in the page (e.g. because the user is on a different browser tab), no page ping fires.

Lifecycle autotracking is only available on mobile apps (iOS and Android). When configured (it is enabled by default), a Lifecycle context entity is attached to all events. It records whether the app was visible or not when the event was tracked. In addition, a Background event will be tracked when the app is moved to background, and a Foreground event when the app moves back to foreground (becomes visible on the screen).

Screen engagement autotracking is also only available on mobile apps (iOS and Android). When configured (it is enabled by default), a screen summary context entity will be tracked along with screen end, foreground and background events. Make sure that you have lifecycle autotracking enabled for screen summary to have complete information.

See this page for information about anonymous tracking.

Configuration of emitter properties: EmitterConfiguration

This Configuration class was added in v0.3.0. Currently, the only property is serverAnonymisation.

serverAnonymisationbool?Prevents tracking of server-side user identifiers.false

Configuration of subject information: SubjectConfiguration

Subject information are persistent and global information about the tracked device or user. They apply to all events and are assigned as event properties.

Some of the properties are only configurable on iOS and Android and are automatically assigned on the Web.

userIdString?Business ID of the user.
networkUserIdString?Network user ID (UUIDv4).Non-configurable, auto-assigned.
domainUserIdString?Domain user ID (UUIDv4).Non-configurable, auto-assigned.
userAgentString?Custom user-agent. It overrides the user-agent used by default.Non-configurable, auto-assigned.
timezoneString?The timezone label.Non-configurable, auto-assigned.
languageString?The language set on the device.Non-configurable, auto-assigned.
screenResolutionSize?The screen resolution on the device.Non-configurable, auto-assigned.
screenViewportSize?The screen viewport.Non-configurable, auto-assigned.
colorDepthdouble?The color depth.Non-configurable, auto-assigned.

The configured attributes are mapped to Snowplow event properties described in the Snowplow Tracker Protocol. They are mapped as follows:

AttributeEvent Property

GDPR context entity configuration: GdprConfiguration

Determines the GDPR context that will be attached to all events sent by the tracker.

basisForProcessingStringBasis for processing.
documentIdStringID of a GDPR basis document.
documentVersionStringVersion of the document.
documentDescriptionStringDescription of the document.
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