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Swift (iOS)

This SDK supports the following platforms and versions:

  • iOS 12 and above
  • Apple TvOS 12 and above
  • Apple WatchOS 5.0 and above

Installation​

CocoaPods​

Add the following to your podfile:

source 'https://github.com/CocoaPods/Specs.git'

target 'MyApp' do
  pod 'GrowthBook-IOS'
end

Then, install:

pod install

Swift Package Manager (SPM)​

Add GrowthBook to your Package.swift file:

dependencies: [
  .package(url: "https://github.com/growthbook/growthbook-swift.git")
]

Quick Usage​

// First, create a GrowthBook instance using your unique features endpoint
var gb: GrowthBookSDK = GrowthBookBuilder(
  // Your GrowthBook feature flag endpoint
  url: "https://cdn.growthbook.io/api/features/sdk-abc123"
).initializer()

// Then, add targeting attributes so you can control the release of your features
// TODO: Replace with your real targeting attributes
var attrs = [
  "id": "12345",
  "deviceId": "abc123",
  "loggedIn": true,
  "country": "US"
]
gb.setAttributes(attrs)

// Finally, start feature flagging!

// Boolean (On/Off) Feature Flag
if (gb.isOn("feature-usage-code")) {
  // Feature is enabled!
}

// String/Number/JSON Feature Flag with a fallback
var value = gb.getFeatureValue("button-color", "blue")
print(value)

Loading Features​

In order for the GrowthBook SDK to work, it needs to have feature definitions from the GrowthBook API. There are 2 ways to get this data into the SDK.

Built-in Fetching and Caching​

If you pass a url into GrowthBookBuilder, it will handle the network requests, caching, retry logic, etc. for you automatically. If your feature payload is encrypted, you can also pass in an encryptionKey and it will decrypt feature flags automatically.

var gb: GrowthBookSDK = GrowthBookBuilder(
  // Your feature flag endpoint
  url: "https://cdn.growthbook.io/api/features/sdk-abc123",
  // View your encryption key on the Features → SDKs page
  encryptionKey: "abcdef98765"
).initializer()

If you want to refresh the features at any time (e.g. when a navigation event occurs), you can call gb.refreshCache().

Custom Integration​

If you prefer to handle the network and caching logic yourself, you can instead pass in a features JSON object directly. For example, you might store features in Postgres on your back-end and send it down to your app as part of an initial bootstrap API call.

var gb: GrowthBookSDK = GrowthBookBuilder(
  features: [
    "feature1": Feature(defaultValue: true)
  ]
).initializer()

Experimentation (A/B Testing)​

In order to run A/B tests on your feature flags, you need to set up a tracking callback function. This is called every time a user is put into an experiment and can be used to track the exposure event in your analytics system (Segment, Mixpanel, GA, etc.).

var gb: GrowthBookSDK = GrowthBookBuilder(
  // Your feature flag endpoint
  url: "https://cdn.growthbook.io/api/features/sdk-abc123",
  // Called whenever someone is put into an experiment
  trackingCallback: { experiment, experimentResult in
    // TODO: Track in your real analytics system
    print("Viewed Experiment")
    print("Experiment Id: ", experiment.key)
    print("Variation Id: ", experimentResult.variationId)
  }
).initializer()

Reference​

View detailed docs on the GitHub Repo