Variation Distribution

When running an A/B Test, you need to distribute users across variations and write logic for each variation. You can use the Hackle SDK to handle this distribution.

variation

Pass the Experiment Key to the variation() method to distribute the user and receive the result.

Parameter	Type	Required	Constraints
Experiment Key (key)	int	Required	-

Example

The example code below passes Experiment Key 42, where there are two variations: A and B.

Swift

// Decides the variation to expose to the user in the A/B Test with Experiment Key 42.
// Returns variation A if the variation cannot be decided.
let variation = hackleApp.variation(experimentKey: 42)

// Logic for the assigned variation
if variation == "A" {
  // Logic for variation A
} else if variation == "B" {
  // Logic for variation B
}

Objective-C

// Decides the variation to expose to the user in the A/B Test with Experiment Key 42.
// Returns variation A if the variation cannot be decided.
NSString *variation = [app variationWithExperimentKey:42];

// Logic for the assigned variation
if([variation isEqual:@"A"]) {
    // Logic for variation A
} else if ([variation isEqual:@"B"]) {
    // Logic for variation B
}

variationDetail

The variationDetail() method works the same as variation() but also provides the reason for the distribution decision. This method is useful for verifying that distribution is working correctly.

Parameter	Type	Required	Constraints
Experiment Key (key)	int	Required	-

Example

You must pass the Experiment Key as a parameter. The example code below passes Experiment Key 42.

Swift

// Distribution decision detail
let decision: Decision = hackleApp.variationDetail(experimentKey: 42)

// Assigned variation
let variation: String = decision.variation

// Reason for the distribution decision
let reason: String = decision.reason

Objective-C

// Distribution decision detail
HackleDecision *decision = [hackleApp variationDetailWithExperimentKey:42];

// Assigned variation
NSString *variation = [decision variation];

// Reason for the distribution decision
NSString *reason = [decision reason];

Distribution Reason

The distribution reason is returned in the format SDK_NOT_READY. See the table below for details.

Distribution Reason	Description	Distribution Result
SDK_NOT_READY	The SDK is not ready to use. (e.g., initialization attempted with an invalid SDK Key)	A (Control Group)
EXPERIMENT_NOT_FOUND	No A/B Test was found for the provided Experiment Key. The Experiment Key may be incorrect, or the experiment may be archived.	A (Control Group)
NOT_IN_MUTUAL_EXCLUSION_EXPERIMENT	The experiment is included in Mutually Exclusive Settings, but the user was not assigned to that Mutually Exclusive Group.	A (Control Group)
EXPERIMENT_DRAFT	The A/B Test is in draft state.	A (Control Group)
EXPERIMENT_PAUSED	The A/B Test is paused.	A (Control Group)
EXPERIMENT_COMPLETED	The A/B Test has ended.	Winning Variation selected at completion
OVERRIDDEN	The user was assigned to a specific group by Override.	Override-assigned group
NOT_IN_EXPERIMENT_TARGET	The user is not an A/B Test target.	A (Control Group)
TRAFFIC_NOT_ALLOCATED	The A/B Test is running, but the user was not allocated to the test.	A (Control Group)
TRAFFIC_ALLOCATED	The user has been allocated to the A/B Test.	Allocated group
VARIATION_DROPPED	The originally allocated group has been removed from the test.	A (Control Group)
INVALID_INPUT	The input value is invalid.	A (Control Group)
EXCEPTION	An unknown error occurred.	A (Control Group)

Parameters

This feature is supported in iOS SDK 2.9.0 and above.

• The variationDetail() method also returns the parameter values for the assigned variation.

• The Decision instance returned by variationDetail() contains a ParameterConfig object with all parameter configuration.

• Since parameters set on the Hackle A/B Test screen exist as key-value pairs, you can use the methods below to retrieve parameter values according to the configured parameter type.

• You can query the configured values for the assigned variation using the functions below.

getString	Returns a parameter value configured as STRING or JSON type.
getInt	Returns a parameter value configured as NUMBER type as an Int.
getDouble	Returns a parameter value configured as NUMBER type as a Double.
getBool	Returns a parameter value configured as Bool type.

Example

Swift

let decision: Decision = hackleApp.variationDetail(experimentKey: 42)
let config: ParameterConfig = decision.config

let strValue: String = decision.getString(forKey: "parameter_key_string_type", defaultValue: "defaultValue")
let strValueInConfig: String = config.getString(forKey: "parameter_key_string_type", defaultValue: "defaultValue")

let jsonValue: String = decision.getString(forKey: "parameter_key_json_type", defaultValue: "defaultValue")
let jsonValueInConfig: String = config.getString(forKey: "parameter_key_json_type", defaultValue: "defaultValue")

let intValue: Int = decision.getInt(forKey: "parameter_key_number_type", defaultValue: 0)
let intValueInConfig: Int = config.getInt(forKey: "parameter_key_number_type", defaultValue: 0)

let doubleValue: Double = decision.getDouble(forKey: "parameter_key_number_type", defaultValue: 0.0)
let doubleValueInConfig: Double = config.getDouble(forKey: "parameter_key_number_type", defaultValue: 0.0)

let boolValue: Bool = decision.getBool(forKey: "parameter_key_boolean_type", defaultValue: false)
let boolValueInConfig: Bool = config.getBool(forKey: "parameter_key_boolean_type", defaultValue: false)

Objective-C

HackleDecision *decision = [hackleApp variationDetailWithExperimentKey:42];

NSString *stringValue = [decision getStringForKey:@"parameter_key_string_type" defaultValue:@"defaultValue"];

NSString *jsonValue = [decision getStringForKey:@"parameter_key_json_type" defaultValue:@"defaultValue"];