Javascript API Reference

Flagger

init

Flagger.init(options): Promise<void>

init method gets FlaggerConfiguration, establishes and maintains SSE connections and initializes Ingester

Note: init must be called only once, at the start of your application. Your program must wait for the promise to resolve before using any other Flagger methods

Provide <API_KEY> either by passing it directly to init method as an argument or by setting environment variable

import Flagger from 'flagger'

await Flagger.init({
  apiKey: '<API-KEY>', // could be omitted if FLAGGER_API_KEY env variable is set
  logLevel: 'DEBUG', // could be omitted, ERROR by default
})
nameEnvironment variableDefaultDescription
apiKeyFLAGGER_API_KEYNoneAPI key to an environment
sourceURLFLAGGER_SOURCE_URLhttps://flags.airdeploy.io/v3/config/URL to get FlaggerConfiguration
backupSourceURLFLAGGER_BACKUP_SOURCE_URLhttps://backup-api.airshiphq.com/v3/config/backup URL to get FlaggerConfiguration
sseURLFLAGGER_SSE_URLhttps://sse.airdeploy.io/v3/sse/URL for real-time updates of FlaggerConfiguration via sse
ingestionURLFLAGGER_INGESTION_URLhttps://ingestion.airdeploy.io/v3/ingest/URL for ingestion
logLevelFLAGGER_LOG_LEVELERRORset up log level: ERROR, WARN, DEBUG. Debug is the most verbose level and includes all Network requests
  • If <API_KEY> is not provided init promise is rejected
  • Passing argument directly to init function overrides corresponding environment variable
  • If not provided default arguments values are used and printed to Debug
  • If second (third …) call of init happens:
    • If the arguments are the same, init method does nothing
    • If arguments differ, Flagger prints warnings and recreates(closes and creates new) resources(SSE connection, Ingester, gets new FlaggerConfiguration).

    • Note: you must call init only once

  • If initial FlaggerConfiguration is not fetched from source/backup, Flagger prints a warning
  • If Flagger fails to get FlaggerConfiguration then all Flags Functions return Default Variation
  • If Flagger fails to establish SSE connection, it retries every 30 seconds until succeeded
  • If you call any Flag Function BEFORE init promise is resolved then you get Default Variation

shutdown

Flagger.shutdown(): Promise<void>

ingests data(if any), stops ingester and closes SSE connection.

Note: you must call shutdown only once before the end of the application runtime.

await Flagger.shutdown()

addFlaggerConfigUpdateListener

public static addFlaggerConfigUpdateListener(
    listener: (config: IFlaggerConfiguration) => void
  ): void

Add a listener to subscribe to event when Flagger gets new FlaggerConfiguration

removeFlaggerConfigUdateListener

public static removeFlaggerConfigUpdateListener(
    listener: (config: IFlaggerConfiguration) => void
  ): void

Removes a listener

publish

Flagger.publish(entity: Entity): void

Explicitly notifies Airdeploy about an Entity

Flagger.publish({id: '1'})

track

Flagger.track(eventName: String, eventProperties: Object, entity: Entity): void

Event tracking API. Entity is an optional parameter if it was set before.

Flagger.track(
  'Purchase Completed',
  {
    plan: 'Gold',
    referrer: 'www.Google.com',
    shirt_size: 'medium',
  },
  {id: '543'}
)

// If `entity` has been set before:
Flagger.track('Purchase Completed', {
  plan: 'Gold',
  referrer: 'www.Google.com',
  shirt_size: 'medium',
})

setEntity

Flagger.setEntity(entity: Entity): void

setEntity stores an entity in Flagger, which allows omission of entity in other API methods.

const entity = {
  id: '543',
  type: 'User', // optional - type defaults to "User"
  name: 'John Smithson',
}
Flagger.setEntity(entity)

// here we are omitting, because Flagger has already stored "entity"
Flagger.isEnabled('stripe-payment')
Flagger.track('some-event', {content: 'some-text'})

// Flagger will use "differentEntity", because it will override "entity"
const differentEntity = {id: '94239643'}
Flagger.isEnabled('strip-payment', differentEntity)

Flagger.setEntity(null) // to remove global entity

If you don't provide any entity to Flagger:

  • flag functions always resolve with the default variation
  • track method doesn't record an event

Rule of thumb: make sure you always provide an entity to the Flagger

isEnabled

Flagger.isEnabled(codename: String, entity: Entity): Boolean

Determines if flag is enabled for entity.

const isEnabled = Flagger.isEnabled('color-theme', {id: '1'})

Group example:

const entityWithGroup = {
  type: 'User',
  id: '19421826',
  group: {type: 'Company', id: '52272353'},
}
const isEnabled = Flagger.flagisEnabled('color-theme', entityWithGroup)

isSampled

Flagger.isSampled(codename: String, entity: Entity): Boolean

Determines if entity is within the targeted subpopulations

const isSampled = Flagger.isSampled('color-theme', {id: '1'})

Group example:

const entityWithGroup = {
  type: 'User',
  id: '19421826',
  group: {type: 'Company', id: '52272353'},
}
const isSampled = Flagger.isSampled('color-theme', entityWithGroup)

getVariation

Flagger.getVariation(codename: String, entity: Entity): String

Returns the variation assigned to the entity in a multivariate flag

const variation = Flagger.getVariation('color-theme', {id: '1'})

Group example:

const entityWithGroup = {
  type: 'User',
  id: '19421826',
  group: {type: 'Company', id: '52272353'},
}
const variation = Flagger.getVariation('color-theme', entityWithGroup)

getPayload

Flagger.getPayload(codename: String, entity: Entity): Object

Returns the payload associated with the treatment assigned to the entity

const payload = Flagger.getPayload('color-theme', {id: '1'})

Group example:

const entityWithGroup = {
  type: 'User',
  id: '19421826',
  group: {type: 'Company', id: '52272353'},
}
const payload = Flagger.getPayload('color-theme', entityWithGroup)

isConfigured

Flagger.isConfigured(): boolean

Returns true if init() promise is resolved - i.e., flagger has apiKey and received FlaggerConfiguration from server.

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