Semantic Conventions for mobile events

Status: Experimental

This document defines semantic conventions for instrumentations that emit events on mobile platforms. All mobile events MUST use a namespace of device in the event.name property.

Lifecycle instrumentation

This section defines how to apply semantic conventions when instrumenting application lifecycle.

Device app lifecycle event

Status:

The event name MUST be device.app.lifecycle.

This event represents an occurrence of a lifecycle transition on Android or iOS platform.

The event body fields MUST be used to describe the state of the application at the time of the event. This event is meant to be used in conjunction with os.name resource semantic convention to identify the mobile operating system (e.g. Android, iOS). The android.state and ios.state fields are mutually exclusive and MUST NOT be used together, each field MUST be used with its corresponding os.name value.

Body fields:

Body Field	Type	Description	Examples	Requirement Level	Stability
android.state	enum	This attribute represents the state the application has transitioned into at the occurrence of the event. [1]	created	Conditionally Required if and only if os.name is android
ios.state	enum	This attribute represents the state the application has transitioned into at the occurrence of the event. [2]	active	Conditionally Required if and only if os.name is ios

[1]: The Android lifecycle states are defined in Activity lifecycle callbacks, and from which the OS identifiers are derived.

[2]: The iOS lifecycle states are defined in the UIApplicationDelegate documentation, and from which the OS terminology column values are derived.

android.state has the following list of well-known values. If one of them applies, then the respective value MUST be used; otherwise, a custom value MAY be used.

Value	Description	Stability
background	Any time after Activity.onPause() or, if the app has no Activity, Context.stopService() has been called when the app was in the foreground state.
created	Any time before Activity.onResume() or, if the app has no Activity, Context.startService() has been called in the app for the first time.
foreground	Any time after Activity.onResume() or, if the app has no Activity, Context.startService() has been called when the app was in either the created or background states.

ios.state has the following list of well-known values. If one of them applies, then the respective value MUST be used; otherwise, a custom value MAY be used.

Value	Description	Stability
active	The app has become active. Associated with UIKit notification applicationDidBecomeActive.
background	The app is now in the background. This value is associated with UIKit notification applicationDidEnterBackground.
foreground	The app is now in the foreground. This value is associated with UIKit notification applicationWillEnterForeground.
inactive	The app is now inactive. Associated with UIKit notification applicationWillResignActive.
terminate	The app is about to terminate. Associated with UIKit notification applicationWillTerminate.