Overview
The Event Library enables you to track a user's activity while using a Sync-enabled mobile application. The Event Library can record read and write transactions. Developers can also configure custom events to record button presses, the data displayed in the UI, or other important details.
When you use the Event Library, you can specify the events you want to record. This means opening two realms:
The user realm, where the user does the reading and writing in the client application
The event realm, where the Event Library records scoped and custom events
The data from both realms syncs to your App Services App. The client user never interacts directly with the event realm or its data; and the event realm Sync user can even be different from the user realm.
Because the Event Library generates a large amount of data:
The client device must have enough capacity to store the data
Expect Device Sync usage for the event realm to be higher than the reading and writing in the user realm
El clúster Atlas de respaldo de la aplicación debe tener suficiente capacidad de almacenamiento para gestionar los datos generados por la librería de eventos
Antes de comenzar
La biblioteca de eventos almacena datos en un AuditEvent colección en su fuente de datos Atlas vinculada. Habilitar Modo de desarrollo en su aplicación App Services para permitir que Atlas cree la colección e infiera el esquema a partir de los eventos cargados
Importante
Se requiere sincronización basada en particiones
La biblioteca de eventos no admite la grabación de AuditEvents mediante la sincronización flexible. Esta función requiere una aplicación de servicios de sincronización basada en particiones para grabar datos de AuditEvent.
Enable Event Recording
Para habilitar la grabación de eventos,configure la propiedad Event.Configuration en Realm.Configuration.
You can initialize the EventConfiguration in either of two ways:
Use the default-initialized configuration when you don't need to specify details
Pass additional parameters to customize the event configuration
Default Event Configuration
Si no necesitas especificar parámetros particulares, puedes usar el EventConfiguration inicializado por defecto:
var config = user.configuration(partitionValue: "Some partition value") config.eventConfiguration = EventConfiguration()
Pasar parámetros a la configuración del evento
You can pass optional parameters to customize the EventConfiguration:
metadata: Diccionario de metadatos de tipo String para agregar a cada eventosyncUser: The user to use for syncing event realm(s). If nil, defaults to the user from theRealm.Configuration.partitionPrefix: String prefix to append to the event partition valuelogger: Registrador personalizado para usar en eventos. Si es nil, se utiliza por defecto el registrador del usuario en el realm.errorHandler: The custom error handler called if a Sync error occurs when uploading event data. Ifnil, the SDK logs the event and then callsabort(). Production apps should always define an eventerrorHandlerunless aborting on the error is the desired behavior.
let eventSyncUser = try await app.login(credentials: Credentials.anonymous) var config = user.configuration(partitionValue: "Some partition value") config.eventConfiguration = EventConfiguration(metadata: ["username": "Jason Bourne"], syncUser: eventSyncUser, partitionPrefix: "event-")
Update Event Metadata
You can update metadata even after you have started recording events. Use the updateMetadata() function to replace the metadata supplied in the event configuration with new values.
If you update metadata while an event scope is active, the Event Library does not use the new metadata until the next event scope begins.
var config = user.configuration(partitionValue: "Some partition value") config.eventConfiguration = EventConfiguration(metadata: ["username": "Jason Bourne"], syncUser: user, partitionPrefix: "event-") let realm = try! Realm(configuration: config) let events = realm.events! let updateUsernameScope = events.beginScope(activity: "Update username") // Call some function that updates the user's username updateUsername() updateUsernameScope.commit() // Update the metadata you supplied with the initial EventConfiguration events.updateMetadata(["username": "John Michael Kane"])
Registro Eventos
Interact with the Event Realm
Después de definir la configuración de eventos, puedes invocar la funcionalidad de grabación de eventos con la nueva propiedad events en un realm. Esto devuelve una instancia Event ligada a ese realm.
let realm = try! Realm(configuration: config) let events = realm.events!
Record Read or Write Events
Changed in version 10.36.0: endScope() deprecated for commit() and cancel(), new Scope object
The Event Library records read and write events within the context of a scope. The scope is the period during which the Event Library watches for and records realm activities. You can set different scopes to record different types of events. For example, you might have scopes for specific user flows such as "login", different scopes for different screens, or different scopes for specific compliance-related activities.
Utiliza beginScope(activity: "some activity") para comenzar a registrar un nuevo evento con el nombre de actividad dado. Esto devuelve un objeto Scope, que puedes usar posteriormente para confirmar o cancelar el alcance. El comenzar un alcance registra las actividades que ocurren dentro de ese alcance como eventos de lectura o escritura.
Read events: run queries and instantiate objects. When the scope ends, the event realm records these activities as read events.
Write events: modify objects. When the scope ends, the event realm records the initial state of the object, as well as the new values of any properties that change durign the scope of the event.
Using beginScope to record an event opens the event realm if it is not already open. The SDK opens event realms on the background thread and reports errors to the error callback.
Nota
Overlapping Event Scopes
If more than one event scope is active simultaneously, generated events are recorded by all active scopes.
When you're done recording events for a scope, use commit() to save events that occurred within the scope. When you end the recording, the Event Library saves the event to disk locally. Then, if the device has a network connection, the SDK asynchronously sends the data to the server.
// Read event let readEventScope = events.beginScope(activity: "read object") let person = realm.objects(Person.self).first! print("Found this person: \(person.name)") readEventScope.commit() let mutateEventScope = events.beginScope(activity: "mutate object") // Write event try! realm.write { // Change name from "Anthony" to "Tony" person.name = "Tony" } mutateEventScope.commit()
Alternately, you can cancel() an event scope. This stops recording events, and does not persist the events to disk or to the server.
let eventScope = events.beginScope(activity: "read object") let person1 = realm.objects(Person.self).first! print("Found this person: \(person1.name)") eventScope.cancel()
You can check whether a given scope is currently in progress using the isActive bool. This returns true if you have begun a scope that you have not yet committed or canceled.
let readPersonScope = events.beginScope(activity: "read object") let person2 = realm.objects(Person.self).first! print("Found this person: \(person2.name)") if readPersonScope.isActive { print("The readPersonScope is active") } else { print("The readPersonScope is no longer active") } readPersonScope.cancel()
You can pass an optional completion block to commit() when you finish recording. The SDK calls this block when the event data has been successfully persisted - not when the event realm upload has completed.
let mutateScope = events.beginScope(activity: "mutate object with completion") // Write event try! realm.write { // Add a userId person.userId = "tony.stark@starkindustries.com" } mutateScope.commit(completion: { error in if let error = error { print("Error recording write event: \(error.localizedDescription)") return } print("Successfully recorded a write event") })
Record Custom Events
La librería de eventos te permite registrar clics de botón u otros eventos que no impliquen lecturas y guardados en la base de datos. Utiliza registroEvento para registrar un evento personalizado. Esta función toma los siguientes parámetros:
activity: the activity name. This is an arbitrary string, such as "user registration."eventType: the type of event. This is an arbitrary string, such as "pressed Submit button."data: an optional data payload for the event.completion: an optional completion handler. The Event Library calls this completion block once the event has been saved to the event realm, or if an error occurs. A nil error indicates success.
A custom event doesn't have a scope like read and write events. Instead, recording a custom event is more analogous to firing a trigger.
events.recordEvent(activity: "event", eventType: "custom event")
Event Object Serialization
Serialización de objetos JSON
The Event Library converts each event object to a JSON object. Most Realm types have an analogous JSON representation. For example, a Realm String property becomes a JSON String.
This is how the Event Library represents the types that do not have a direct JSON analog:
fecha | Codificado en una cadena en formato ISO 8601-:.12019 |
Datos | Excluido completamente del evento. |
UUID | Encoded to a RFC-4122-compliant string. |
ObjectID | Codificado en nuestra representación de cadena ObjectID. |
Decimal128 | Encoded to a string, not a number. JSON numbers are officially infinite- precision, but are rarely actually implemented as such. |
Lista | Encoded as an array. |
Configura | Encoded as an array. |
Dictionary | Encoded as an object. |
Objetos incrustados | Encoded as an object. |
Non-embedded object links are encoded as the primary key of the target. In read events, if the link is followed, this expands to the full object. If the link is not followed, this remains a primary key.
Customize Event Serialization
Puede personalizar la serialización JSON de los objetos de evento. Para personalizar la carga útil del evento, utilice el protocolo CustomEventRepresentable.
When an object conforms to CustomEventRepresentable, the Event Library serializes objects by:
Constructing an accessor object
Calling
customEventRepresentationon that accessor objectSerializing the result instead of the original object
Para cumplir con CustomEventRepresentable, tu objeto debe implementar una función customEventRepresentation que defina tu serialización personalizada.
// To customize event serialization, your object must // conform to the `CustomEventRepresentable` protocol. class Person: Object, CustomEventRepresentable { (primaryKey: true) var _id: ObjectId var name: String var employeeId: Int var userId: String? convenience init(name: String, employeeId: Int) { self.init() self.name = name self.employeeId = employeeId } // To conform to `CustomEventRepresentable`, your object // must implement a `customEventRepresentation` func that // defines your customized event serialization func customEventRepresentation() -> String { if employeeId == 0 { return "invalid json" } return "{\"int\": \(employeeId)}" } }
Event Realm File Size
The event realm can grow quite large if the device is offline for an extended time.
To compensate for this, the Event Library automatically splits event data into multiple partitions as needed. When a partition reaches its maximum size, the Event Library closes the event realm and automatically begins writing to a new partition.
The Event Library checks whether the user has any unsynced partitions. If they do, the Event Library opens one, uploads the data, and then closes the file and deletes it. This repeats until the user has no unsynced partitions.
Referencia de la Biblioteca de Eventos
Eventos
The AuditEvent collection where events are stored must have a schema defined on the server for the App receiving events.
The schema must contain the following fields:
ID |
| ObjectId. |
Type of Event |
| Optional string. |
Event Scope |
| Optional string. The scope name passed to |
Marca de tiempo |
| Device local time when the event scope is ended and the data is committed, or the time when the event hits the server. |
Datos |
| The event payload. This is a JSON blob for scoped events, or an arbitrary string for custom events. |
Metadata |
| Un diccionario de metadatos opcional. Cuando este diccionario contiene claves y valores, la clave se convierte en un nombre de campo en el objeto de evento, y el valor se almacena en ese campo para cada evento. |
Event Payload
Cada evento contiene una carga útil en la propiedad data que captura el estado actual de los objetos que se están leyendo o escribiendo.
Payloads for custom events can be whatever the developer desires, including nil.
Importante
Debido a que la carga útil captura el estado actual de los objetos que se están leyendo o escribiendo, esto produce una gran cantidad de datos. Sin embargo, esto debe realizarse en el cliente y no en el servidor, ya que es posible que los datos exactos que ve el usuario nunca existan del lado del servidor. En la práctica, esto significa que el dispositivo debe tener la capacidad de almacenar una gran cantidad de datos si queda sin conexión. Además, el uso de Device Sync para el realm de evento puede ser mucho mayor que para la lectura y escritura que el usuario realiza en el realm de usuario.
Ejemplo
En nuestros ejemplos de eventos de registro anteriores, estas son las data cargas útiles para los eventos de lectura y escritura:
{ "type":"Person", "value": [{ "_id":"62b38b3c10846041166f5deb", "_partition":"", "employeeId":2, "name":"Anthony", "userId":null }] }
{ "Person": { "modifications": [{ "newValue": { "name":"Tony" }, "oldValue":{ "_id":"62b38b3c10846041166f5deb", "_partition":"", "employeeId":2, "name":"Anthony", "userId":null } }] } }