Real-Time Audiences for Feature Experimentation segment qualification methods for the Swift SDK
Prerequisites
You must enable and configure Real-Time Audiences for Feature Experimentation before fetching qualified segments and checking if the user is qualified for the given audience segment.
fetchQualifiedSegments - asynchronous
Minimum SDK version
4.0.0
Description
Fetches all qualified audience segments for the user context.
fetchQualifiedSegments is a method of the UserContext object. See OptimizelyUserContext for details.
Parameters
The following table describes the parameters for the fetchQualifiedSegments method:
Parameter | Type | Description |
|---|---|---|
options (optional) | [OptimizelySegmentOption] | A set of options for fetching qualified segments from ODP. |
completion | (OptimizelyError?) -> Void | A completion handler to be called with the fetch result. |
Returns
The completion handler to be called on completion that updates the qualified segments array.
- On success, it passes a nil error.
- On failure, it passes one of these errors:
- OptimizelyError.invalidSegmentIdentifier
- OptimizelyError.fetchSegmentsFailed.
You can read and write directly to the qualified segments array to bypass the remote fetching process from ODP or use your own fetching service. This can be helpful when testing or debugging.
Example fetchQualifiedSegments – asynchronous
The following is an example of calling the fetchQualifiedSegments method and accessing the returned completion object:
let attributes: [String: Any] = ["app_version": "1.3.2"]
let user = optimizelyClient.createUserContext(userId: "fs-id-123", attributes: attributes)
// Without segment option.
Task {
let attributes: [String: Any] = ["app_version": "1.3.2"]
let user = optimizely.createUserContext(userId: "fs-id-123", attributes: attributes)
try? user.fetchQualifiedSegments()
}
// With segment options.
Task {
var odpSegmentOptions: [OptimizelySegmentOption] = [.ignoreCache, .resetCache]
let attributes: [String: Any] = ["app_version": "1.3.2"]
let user = optimizely.createUserContext(userId: "fs-id-123", attributes: attributes)
try? user.fetchQualifiedSegments(options: odpSegmentOptions)
}fetchQualifiedSegments – synchronous
Minimum SDK version
4.0.0
Description
This is a synchronous version of the fetchQualifiedSegments asynchronous version above.
This call blocks the calling thread until fetching is completed.
Parameters
The following table describes the parameters for the fetchQualifiedSegments method:
Parameter | Type | Description |
|---|---|---|
`options` (optional) | [OptimizelySegmentOption] | A set of options for fetching qualified segments from ODP. |
Returns
This method does not provide a return value. If it fails, it throws one of the following errors:
- OptimizelyError.invalidSegmentIdentifier
- OptimizelyError-fetchSegmentsFailed(String)
Example fetchQualifiedSegments - synchronous
The following is an example of calling the fetchQualifiedSegments method and accessing the returned completion object:
let optimizely = OptimizelyClient(sdkKey: <Your_SDK_Key>)
optimizely.start { result in
let attributes: [String: Any] = ("app version": "1.3.2")
let user = optimizelyClient.createUserContext(userld: "fs-id-123", attributes: attributes)
do {
// this blocks the calling thread until fetch is completed.
try user.fetchQualifiedSegments()
let decision = user.decide(key: "flag1")
} catch OptimizelyError.invalidSeqmentIdentifier {
print("[AudienceSegments] audience segments fetch failed (user id is not registered yet or invalid)")
} catch {
print("[AudienceSegments] \(error)")
}
}The following diagram shows the network calls between your application, the Feature Experimentation Swift SDK, and the ODP server when calling fetchQualifiedSegments:
- Your application calls the fetchQualifiedSegments method.
- The Feature Experimentation Swift SDK makes a GraphQL call to ODP to fetch segments the user ID qualifies for.
- ODP responds with the qualified audience segments.
- The Swift SDK automatically caches the fetched segments mapping the user ID to the qualified segments.
- The fetchQualifiedSegments method returns a boolean if the qualified segments array was updated.
- Call the decide method to get the flag decision for a given user, a decision object that contains the flag's status (enabled or disabled), and the assigned variation key.
The Swift SDK fetches the segments and then caches them. This means that if you are requesting the segments again (when new user contexts are created), you can retrieve the audience segment information from the cache rather than from the remote ODP server.
The cache is used for the fetchQualifiedSegments call. This method is called on the user context (the user context is fixed, including the real-time audiences the user qualifies for).
The cache only applies when calling the fetchQualifiedSegments call. If you set the cache timeout to 0, the cache is disabled. Optimizely uses the least recently used (LRU) algorithm, so the oldest record is bumped out when the maximum size is reached. If there is a cache miss upon the method call, Optimizely makes a network request.
You can add the following options to your odpSegmentOptions array to bypass caching:
- ignoreCache – Bypass segments cache for lookup and save.
- resetCache – Reset all segments cache.
isQualifiedFor
Minimum SDK version
4.0.0
Description
Check if the user qualifies for the given audience segment.
Parameters
The following table describes the parameters for the isQualifiedFor method:
Parameter | Type | Description |
|---|---|---|
segment | String | The ODP audience segment name to check if the user qualifies |
Returns
true if the user is qualified.
Examples
The following is an example of whether the user qualifies for an ODP segment:
let attributes: [String: Any] = ["laptop_os": "mac"]
let user = optimizelyClient.createUserContext(userId: "user123", attributes: attributes)
user.fetchQualifiedSegments { segments, err in
let isQualified = user.isQualifiedFor(segment: "segment1")
}Source files
The language and platform source files containing the implementation for Swift are available on Github.