Flutter SDK Usage

Using Variable Values

To get values from your Variables, the variableValue() method is used to fetch variable values using the variable's identifier key coupled with a default value. The default value can be of type String, Boolean, Number, or JSONObject:

final boolValue = _devcycleClient.variableValue(key: "bool_key", defaultValue: false);
final strValue = _devcycleClient.variableValue(key: "string_key", defaultValue: "default");
final numValue = _devcycleClient.variableValue(key: "num_key", defaultValue: 4);
final jsonValue = _devcycleClient.variableValue(key: "json_key", defaultValue: { "key": "value" });

If you would like to get the full Variable object using the variable() method it also contains the following params:

• key: the key identifier for the Variable
• type: the type of the Variable, one of: String / Boolean / Number / JSON
• value: the Variable's value
• defaultValue: the Variable's default value
• isDefaulted: if the Variable is using the defaultValue
• evalReason: evaluation reason for why the variable was bucketed into its value

If the value is not ready, it will return the default value passed in the creation of the variable.

Variable Updates

Variable values update whenever identifyUser() or resetUser() are called, or when the project configuration changes (to learn more, visit our Realtime Updates page).

To listen for variable updates, the onUpdate() method can be used on a Variable Object. Please note, a strong reference to the variable is needed for onUpdate to be triggered.

final variable = await _devcycleClient.variable('my-variable', 'Default Value');
variable?.onUpdate((updatedVariable) {
    // Variable value updated updatedVariable.value
});

Get All Variables

To get all the variables returned in the config:

Map<String, DVCVariable> variables = await _devcycleClient.allVariables();

If the SDK has not finished initializing, these methods will return an empty object.

caution

This method is intended to be used for debugging and analytics purposes, not as a method for retrieving the value of Variables to change code behaviour. For that purpose, we strongly recommend using the individual variable access method described in Using Variable Values Using this method instead will result in no evaluation events being tracked for individual variables, and will not allow the use of other DevCycle features such as Code Usage detection

Get All Features

To get all the Features returned in the config:

Map<String, DVCFeature> features = await _devcycleClient.allFeatures();

If the SDK has not finished initializing, these methods will return an empty object.

Identifying User

To identify a different user, or the same user passed into the initialize method with more attributes, build a DevCycleUser object and pass it into identifyUser:

DevCycleUser user = DevCycleUserBuilder()
    .userId('my-user1')
    .email('my-email@email.com')
    .country("CA")
    .name("My Name")
    .language("EN")
    .customData({ "customkey": "customValue" })
    .privateCustomData({ "customkey2": "customValue2" })
    .build();

_devcycleClient.identifyUser(user);

To wait on Variables that will be returned from the identify call, you can pass in a callback:

_devcycleClient.identifyUser(user, (error, variables) => {
    // Error or Variables for the Identified User
});

If error exists the called the user's configuration will not be updated and previous user's data will persist.

Reset User

To reset the user into an anonymous user, resetUser will reset to the anonymous user created before or will create one with an anonymous user_id.

_devcycleClient.resetUser();

To wait on the Variables of the anonymous user, you can pass in a callback:

_devcycleClient.resetUser((error, variables) => {
    // Error or Variables for Anonymous User
});

If error exists is called the user's configuration will not be updated and previous user's data will persist.

Tracking Events

To track events, pass in an object with at least a type key:

DevCycleEvent event = DevCycleEventBuilder()
    .target('my_target')
    .type('my_event')
    .value(3)
    .date(DateTime.now())
    .metaData({ 'key': 'value' })
    .build();

_devcycleClient.track(event);

The SDK will flush events every 10s or flushEventsMS specified in the options. To manually flush events, call:

_devcycleClient.flushEvents();

An Error callback can also be passed to this method, that will be triggered if there is a non-recoverable failure when flushing events.

_devcycleClient.flushEvents(([error]) => {
    // Error or null for Flushing Events
});

EdgeDB

EdgeDB allows you to save user data to our EdgeDB storage so that you don't have to pass in all the user data every time you identify a user. Read more about EdgeDB.

To get started, contact us at support@devcycle.com to enable EdgeDB for your project.

Once you have EdgeDB enabled in your project, pass in the enableEdgeDB option to turn on EdgeDB mode for the SDK:

DevCycleUser user = DevCycleUserBuilder()
    .userId('test_user')
    .email('test@example.com')
    .customData({ "amountSpent": 50 })
    .build();

DevCycleOptions options = DevCycleOptionsBuilder()
    .enableEdgeDB(true)
    .build();

This will send a request to our EdgeDB API to save the custom data under the user test-user.

In the example, amountSpent is associated to the user test-user. In your next identify call for the same userId, you may omit any of the data you've sent already as it will be pulled from the EdgeDB storage when segmenting to experiments and features.