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.
func (o *OptimizelyClient) GetFeatureVariableBoolean(featureKey, variableKey string, userContext entities.UserContext) (value bool, err error)
Double
Returns the value of the specified double variable.
func (o *OptimizelyClient) GetFeatureVariableDouble(featureKey, variableKey string, userContext entities.UserContext) (value float64, err error)
Integer
Returns the value of the specified integer variable.
func (o *OptimizelyClient) GetFeatureVariableInteger(featureKey, variableKey string, userContext entities.UserContext) (value int, err error)
String
Returns the value of the specified string variable.
func (o *OptimizelyClient) GetFeatureVariableString(featureKey, variableKey string, userContext entities.UserContext) (value string, err error)
JSON
Returns the value of the specified JSON variable.
func (o *OptimizelyClient) GetFeatureVariableJSON(featureKey, variableKey string, userContext entities.UserContext) (optlyJSON *optimizelyjson.OptimizelyJSON, err error)
Version
SDK v1.0
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 IsFeatureEnabled, 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
The table below lists the required and optional parameters in Go.
Parameter | Type | Description |
---|---|---|
featureKey required | string | The feature key is defined from the Features dashboard; see Use feature flags. |
variableKey required | string | The key that identifies the feature variable. For more information, see: Create feature variables. |
userContext required | entities.UserContext | Holds information about the user, such as the userID and the user's attributes. |
Returns
The value this method returns is determined by your feature flags. This example shows the specific value returned for Go:
API | Return |
---|---|
GetFeatureVariableBoolean | @return The value of the variable, or false with error if the feature key is invalid, the variable key is invalid, or there is a mismatch with the type of the variable. |
GetFeatureVariableDouble | @return The value of the variable, or 0.0 with error if the feature key is invalid, the variable key is invalid, or there is a mismatch with the type of the variable. |
GetFeatureVariableInteger | @return The value of the variable, or 0 with error if the feature key is invalid, the variable key is invalid, or there is a mismatch with the type of the variable. |
GetFeatureVariableString | @return The value of the variable, or empty-string with error if the feature key is invalid, the variable key is invalid, or there is a mismatch with the type of the variable. |
Example
This section shows an example of how you can use the getFeatureVariableInteger
method.
attributes := map[string]interface{}{
"DEVICE": "iPhone",
"hey": 2,
}
user := entities.UserContext{
ID: "userId",
Attributes: attributes,
}
value, err := optlyClient.GetFeatureVariableInteger("feature_key", "variable_key", user)
Side effects
The table lists other Optimizely functionality that may be triggered by using this method.
Functionality | Description |
---|---|
Notifications | Invokes the DECISION [notification] is this notification is subscribed to. |
The example code below shows how to add and remove a decision listener.
import (
"fmt"
"github.com/optimizely/go-sdk/pkg/client"
"github.com/optimizely/go-sdk/pkg/notification"
)
// Callback for decision notification
callback := func(notification notification.DecisionNotification) {
// Access type on decisionObject to get type of decision
fmt.Print(notification.Type)
// Access decisionInfo on decisionObject which
// will have form as per type of decision.
fmt.Print(notification.DecisionInfo)
}
optimizelyClient, err := optimizelyFactory.Client()
// Add callback for decision notification
id, err := optimizelyClient.DecisionService.OnDecision(callback)
// Remove callback for decision notification
err = optimizelyClient.DecisionService.RemoveOnDecision(id)
Exceptions
None
Source files
The language/platform source files containing the implementation for Go is Go.
Updated almost 3 years ago