Get Feature Variable
This topic describes the Get Feature Variable method which evaluates the specified feature variable of a specific variable type and returns its value.
Evaluates the specified feature variable of a specific variable type and returns its value.
This method is used to evaluate and return a feature variable. Multiple versions of this method are available and are named according to the data type they return:
This method takes into account the user attributes passed in, to determine if the user is part of the audience that qualifies for the experiment.
Boolean
Returns the value of the specified Boolean variable.
public func getFeatureVariableBoolean(featureKey: String,
variableKey: String,
userId: String,
attributes: OptimizelyAttributes?=nil) throws -> Bool
- (NSNumber *)getFeatureVariableBooleanWithFeatureKey:(nullable NSString *)featureKey
variableKey:(nullable NSString *)variableKey
userId:(nullable NSString *)userId
attributes:(nullable NSDictionary<NSString *, NSString *> *)attributes
error:(nullable NSError **)error;
Double
Returns the value of the specified double variable.
public func getFeatureVariableDouble(featureKey: String,
variableKey: String,
userId: String,
attributes: OptimizelyAttributes?=nil) throws -> Double
- (NSNumber *)getFeatureVariableDoubleWithFeatureKey:(nullable NSString *)featureKey
variableKey:(nullable NSString *)variableKey
userId:(nullable NSString *)userId
attributes:(nullable NSDictionary<NSString *, NSString *> *)attributes
error:(nullable NSError **)error;
Integer
Returns the value of the specified integer variable.
public func getFeatureVariableInteger(featureKey: String,
variableKey: String,
userId: String,
attributes: OptimizelyAttributes?=nil) throws -> Integer
- (NSNumber *)getFeatureVariableIntegerWithFeatureKey:(nullable NSString *)featureKey
variableKey:(nullable NSString *)variableKey
userId:(nullable NSString *)userId
attributes:(nullable NSDictionary<NSString *, NSString *> *)attributes
error:(nullable NSError **)error;
String
Returns the value of the specified string variable.
public func getFeatureVariableString(featureKey: String,
variableKey: String,
userId: String,
attributes: OptimizelyAttributes?=nil) throws -> String
- (NSString *_Nullable)getFeatureVariableStringWithFeatureKey:(nullable NSString *)featureKey
variableKey:(nullable NSString *)variableKey
userId:(nullable NSString *)userId
attributes:(nullable NSDictionary<NSString *, NSString *> *)attributes
error:(nullable NSError **)error;
JSON
Returns the value of the specified JSON variable.
public func getFeatureVariableJSON(featureKey: String,
variableKey: String,
userId: String,
attributes: OptimizelyAttributes? = nil) throws -> OptimizelyJSON
Version
SDK v3.0, v3.1
Description
Each of the Get Feature Variable methods follows the same logic as Is Feature Enabled:
- Evaluate any feature tests running for a user.
- Check the default configuration on a rollout.
The default value is returned if neither of these are applicable for the specified user, or if the user is in a variation where the feature is disabled.
Important
Unlike Is Feature Enabled, the Get Feature Variable methods do not trigger an impression event. This means that if you are running a feature test, events will not be counted until you call Is Feature Enabled. If you do not call Is Feature Enabled, you will not see any visitors on your results page.
Parameters
Required and optional parameters are listed below.
| Parameter | Type | Description |
|---|---|---|
| featureKey required | string | The feature key is defined from the Features dashboard. |
| variableKey required | string | The key that identifies the feature variable. |
| userId required | string | The user ID string uniquely identifies the participant in the experiment. |
| attributes required | map | A map of custom key-value string pairs specifying attributes for the user that are used for audience targeting and results segmentation. Non-string values are only supported in the 3.0 SDK and above. |
Returns
The value of the variable
Example
let attributes = [
"device": "iPhone",
"lifetime": 24738388,
"is_logged_in": true,
]
let featureVariableValue = try? optimizelyClient?.getFeatureVariableDouble(featureKey:"my_feature_key", variableKey:"double_variable_key", userId:"user_123", attributes:attributes)
NSDictionary *attributes = @{
@"device": @"iPhone",
@"lifetime": @24738388,
@"is_logged_in": @true
};
NSNumber *featureVariableValue = [optimizelyClient getFeatureVariableDouble:@"my_feature_key"
variableKey:@"double_variable_key"
userId:@"user_123"
attributes:attributes
error:nil];
Side effects
In SDKs v3.1 and later: Invokes the DECISION notification listener if this listener is enabled.
Source files
The language/platform source files containing the implementation for Swift is OptimizelyClient.swift.
Updated over 2 years ago