Flutter V1.3.X

Introduction

SDK overview

Welcome to the Flagship Flutter SDK documentation!

The following documentation helps you run Flagship on your Flutter app using our client library.

Feel free to contact us if you have any questions regarding this documentation.

SDK features

This SDK version will help you:

Prequisites

  • Flagship SDK supports Dart 2.12.0 minimum or higher
  • Flagship is null safety

Good to know

Getting Started

Our Flagship flutter SDK is available for distribution through pub.dev

Installing

Run this command:

flutter pub add flagship

This will add a line like this to your package's pubspec.yaml (and run an implicit dart pub get):

dependencies:
  flagship: ^1.3.0

Initialization

To run experiments with Flagship, you will need to start the SDK using:

start(String envId, String apiKey, {FlagshipConfig? config})

ParameterTypeRequiredDescription
envIdStringYesIdentifies your Flagship account and environment (preprod or prod). Find this ID
apiKeyStringYesIdentifies your Flagship api key (preprod or prod). Find this api key
configFlagshipConfigNoObject that represent client's configuration

📘

You can get your own envId & API Key in the Flagship Platform.

  1. Navigate to SettingsAPI Key & Settings
  2. Copy the environment ID & API Key
// import package
import 'package:flagship/flagship.dart';
import 'package:flagship/utils/logger/log_manager.dart';

//////////////////////////////////////////////
/////// Start sdk with default options ///////
//////////////////////////////////////////////

Flagship.start("your_env_id", "your_api_key");


//////////////////////////////////////////////
/////// Start sdk with custom options  ///////
//////////////////////////////////////////////

// - timeout   = 1500 ms
// - level     = warning message
// - activated = true
// - statusListener callback 
    Flagship.start("your_env_id", "your_api_key",
        config: FlagshipConfig(
            timeout: 1500,
            logLevel: Level.WARNING,
            activeLog: true,
            statusListener: (newStatus) {
              // This callback is triggered when the SDK status has changed
            }));

Flagship configuration options

The sdk provides the FlagshipConfig object in the start function as an optional parameter where we can set the desired configuration

FlagshipConfig(this.timeout,{Level logLevel = Level.ALL, bool activeLog = true})

Parameter

Type

Required

Description

timeout

int

No

Timeout to fetch campaigns. The default value is 2000 ms (Milliseconds).

statusListener

void Function(Status newStatus)

No

Called when the sdk status changed

logLevel

Level

No

Log's level of detail : NONE(0), EXCEPTIONS(1), ERROR(2), WARNING(3), DEBUG(4), INFO(5), ALL(6) which is the default value

activeLog

bool

No

By default the value is true (activated logs)

Timeout:

This delay only concerns the request for fetching campaigns under the API mode. If the API didn't answer during this interval of time, the default values will be returned from the getModification function.

📘

The Timeout default value is 2000 Milliseconds

statusListener:

This listener is called when SDK status has changed.

//-- Code Sample: Status listener --// 

// Create a configuration object with status listener
   FlagshipConfig config = FlagshipConfig(statusListener: (Status newStatus) {
      switch (newStatus) {
        case Status.READY:
          // Create or use a visitor
          break;
        default:
      }
    });

logLevel :
You can change log's level of detail durring the runtime void setLoggerLevel(Level newLevel)

// Change the log's level of detail
Flagship.setLoggerLevel(Level.INFO);

📘

The default value for the level of detail is Level.ALL

activeLog :
You can enable or disable the logger durring the runtime void enableLog(bool isLogEnabled)

// Disable logs
Flagship.enableLog(false);

📘

The default value for activeLog is true

Display logs

void logger(Level level, String message, {bool isJsonString = false})

ParameterTypeRequiredDescription
levelLevelYesLevel of details regarding messages
messageStringYesMessage to display
isJsonStringboolNoFalse by default, use true when it's about json representation to get a pretty print
//////////////////////////////////////////////////
/////// Logger function to display message ///////
//////////////////////////////////////////////////

Flagship.logger(Level.ALL, "start sdk");

SDK Status

It is possible to get the current status via the method getStatus() from the Flagship class.

  • static Status getStatus()

Return an enum that represent the current SDK status

List of the possible SDK status :

Status

Description

NOT_INITIALIZED

Flagship SDK has not been started or initialized successfully.

PANIC_ON

Flagship SDK is ready but is running in Panic mode: All visitor's features are disabled except 'fetchFlags' which refreshes this status.

READY

Flagship SDK is ready to use.

// Get the current status for the SDK
   var currentStatus = Flagship.getStatus();

// Using getStatus to check if the SDK is READY

  // Create the visitor 
   var visitor = Flagship.newVisitor("user1",{"isVip":true});

  // Fetch Flags the modifications 
   visitor.fetchFlags().whenComplete(() {
    
  // Get the status and check the mode
    Status currentState =  Flagship.getStatus();
    if (currentState == Status.READY) {
      // The SDK is ready
    }
  });

Create a visitor

Once Flagship SDK is initialized, you can create a visitor.

newVisitor(String envId, String apiKey, String visitorId,Map<String, Object> context,{bool hasConsented = true})

ParameterTypeRequiredDescription
visitorIdStringYesUnique identifier for the current visitor. This can be an ID from your database or a session ID. If no value is passed, the SDK will automatically generate a unique ID. Learn more
contextMap<String, Object>YesContext that represent the visitor's attributs. ex {"isVip":true}
hasConsentedboolNoSpecify if the visitor has consented for personal data usage. true by default.

The visitor context is a property dataset that defines the current visitor of your app.
This dataset is sent and used by the Flagship Decision API as targeting criteria for campaign assignment.

For example, if you want to enable or disable a specific feature based on VIP status, you would pass this attribute as a key-value pair in the visitor context so that the Decision API can enable or disable the corresponding feature flag for the visitor.

// import package
import 'package:flagship/flagship.dart';

//////////////////////////////////////////////
/////// Create visitor with no consent ///////
//////////////////////////////////////////////
var visitor = Flagship.newVisitor("your_visitorId", {"isVip": true}, hasConsented: false);

📘

  • Context keys must have a type of String
    • Context values must have a type of String, bool, int,double
    • User context keys and values are case sensitive

Get & Set the current visitor

Most of the time, your Flutter application will handle only 1 visitor at any given time.
For that use case, Flagship implement 2 useful methods to store the created visitor as the current singleton visitor instance.

static setCurrentVisitor(Visitor visitor)

Stores the current visitor instance created at the newVisitor.

// import package
import 'package:flagship/flagship.dart';

//////////////////////////////////////////
/////// set the current visitor //////////
//////////////////////////////////////////
var visitor = Flagship.newVisitor("your_visitorId", {"isVip": true});
Flagship.setCurrentVisitor(visitor);

static Visitor? getCurrentVisitor()

Return the current visitor instance stored when setting the current visitor.

// import package
import 'package:flagship/flagship.dart';

//////////////////////////////////////////
/////// Get the current visitor //////////
//////////////////////////////////////////

var visitor = Flagship.getCurrentVisitor();

🚧

This method returns a nullable Visitor (in case the current visitor has not been previously set).
Make sure to check whether it is null or not before using it.

Updating the visitor context

The visitor context is a property dataset that defines the current visitor of your app. This dataset is sent and used by the Flagship Decision API as targeting criteria for campaign assignment.

The following method from the Visitor instance allows you to set new context values matching the given keys.

void updateContext(String key, Object value)

Update the visitor context values, matching the given keys, used for targeting. Only String, bool, int, double typed values are accepted.

ParameterTypeDescription
keyStringContext key.
valueObjectContext value.

void updateContextWithMap(Map<String, Object> context)

Update the visitor context values, matching the given keys, used for targeting. Only String, bool, double and int type values are accepted.

ParameterTypeDescription
contextMap<String, Object>Map of keys, values.

📘

  • User context keys must have a type of String
    • User context values must have a type of String, bool, double or int
    • User context keys and values are case sensitive
// import package
import 'package:flagship/flagship.dart';

//////////////////////////////
/////// Update context ///////
//////////////////////////////

var currentVisitor = Flagship.getCurrentVisitor();

// Update context with key/value
currentVisitor?.updateContext("lastPurchaseDate", 1615384464);

// Update context with Map
currentVisitor?.updateContextWithMap({"isVip": true, "key1": 12.5, "key2": "title", "key3": 2});

void clearContext()

Empty the visitor context values, used for targeting.

// Import package
import 'package:flagship/flagship.dart';

/////////////////////////////
/////// Clear context ///////
/////////////////////////////

var currentVisitor = Flagship.getCurrentVisitor();

currentVisitor?.clearContext();

Managing visitor campaigns and theirs flags

Fetching Flags

The fetchFlags() method of the visitor instance automatically calls the Flagship Decision API to run campaign assignments according to the current visitor context and retrieve applicable flags.

These flags are updated asynchronously when fetchFlags() is called.

/////////////////////////////////////////
///////     Fetch Flags           ///////
/////////////////////////////////////////

import 'package:flagship/flagship.dart';


// Get the current visitor
var currentVisitor = Flagship.getCurrentVisitor();
// Fetch Flags
currentVisitor?.fetchFlags().whenComplete(() {
  // The fetch is done.
  // If the panic mode is ON or the fetch fail for another reason
  // the value for flag will be a default value
});

Future<void> fetchFlags() async

This function will call the decision api and update all the campaigns flags from the server according to the visitor context.

Getting flags

Once the campaign has been assigned and fetched, all the flags are stored in the SDK.
You can retrieve these flags using the following functions from the Visitor instance:

////////////////////////////////
///////    Get Flag      ///////
////////////////////////////////

import 'package:flagship/flagship.dart';
import 'package:flagship/model/flag.dart';


// Get the current visitor
    var currentVisitor = Flagship.getCurrentVisitor();

// Fetch flags
    currentVisitor?.fetchFlags().whenComplete(() {
      // Ex: get flag for vip feature
      Flag flag = currentVisitor.getFlag("displayVipFeature",false);
    });

// The getFlag function can be directly called through the "currentVisitor" instance if you
// already fetched it elsewhere in the application

Flag getFlag<T>(String key, T defaultValue)

Retrieve a Flag object by its key. If no flag match the given key an empty flag will be returned. Call exists() to check if the flag has been found.

ParameterTypeRequiredDescription
keyStringYesKey associated to the modification.
defaultValueTYesFlag default value to return.

Getting flags current values

To retrieve flag current value, simply call value() method of the Flag object.

  • T value({bool userExposed: true})
    Returns the value from the assigned campaign variation or the Flag default value if the Flag does not exist, or if types are different.

Parameter

Type

Default value

Description

userExposed

bool

true

Tells Flagship the user have been exposed and have seen this flag. This will increment the visits for the current variation on your campaign reporting.
If needed it is possible to set this param to false and call userExposed() afterward when the user has really been exposed to it.

import 'package:flagship/flagship.dart';
import 'package:flagship/model/flag.dart';

// Get the current visitor
    var currentVisitor = Flagship.getCurrentVisitor();

// Fetch flags
    currentVisitor?.fetchFlags().whenComplete(() {
      // Ex: get flag for vip feature
      Flag flag = currentVisitor.getFlag("displayVipFeature", false);

      // Use this flag value to enable displaying the vip feature
      bool shouldDisplayVipFeature = flag.value();
    });

Getting flags campaigns metadata

You may need to send campaign's informations to a third-party for reporting and/or analytics purposes. The metadata method returns a dictionary with values you can use.

  • FlagMetadata metadata()
    Return the campaign metadata or an empty object if the Flag doesn't exist or if the default value type does not correspond to the Flag type in Flagship.
import 'package:flagship/flagship.dart';
import 'package:flagship/model/flag.dart';

// Get the current visitor
    var currentVisitor = Flagship.getCurrentVisitor();

// Fetch flags
    currentVisitor?.fetchFlags().whenComplete(() {
      // Ex: get flag for vip feature
      Flag flag = currentVisitor.getFlag("displayVipFeature", false);

      // Use this flag value to enable displaying the vip feature
      bool shouldDisplayVipFeature = flag.value();
      
      // Use this flag to get the metadata      
        FlagMetadata metadata = flag.metadata();

    });

The metadata you can access to are the following one:

FSFlagMetadata

Type

Default value

Description

campaignId

String

""

id of the campaign

variationGroupId

String

""

Id of the variation group

variationId

String

""

id of the variation assigned

isReference

bool

false

if true that means the assigned variation is the reference, otherwise it's not.

campaignType

String

""

Type of the campaign. Ex: AB

slug

String

""

campaign slug or empty string if not configured in the platform

Report a Flag exposition

By default when the method value() is called, the SDK considers that the user has seen your Flag unless you pass false to value(). In this last case, you will have to call the userExposed() method.

There are two options for exposing a user to a flag:

  • Pass an userExposed=true parameter to the value() method.
  • Use the following userExposed() method from the Flag instance.
  • Future<void> userExposed() async
// Get the current visitor
    var currentVisitor = Flagship.getCurrentVisitor();

// Fetch flags
    currentVisitor?.fetchFlags().whenComplete(() {
      // Ex: get flag for vip feature
      Flag flag = currentVisitor.getFlag("displayVipFeature", false);

      // Use this flag value to enable displaying the vip feature with expose to false
      bool shouldDisplayVipFeature = flag.value(userExposed: false);

      // Expose this flag later in the code
      flag.userExposed();
    });

Check if a Flag exists

  • bool exists()
    This method will return true if a Flag has been returned by Flagship.
// Get the current visitor
    var currentVisitor = Flagship.getCurrentVisitor();

// Fetch flags
    currentVisitor?.fetchFlags().whenComplete(() {
      
     // Ex: get flag for vip feature and check if it exists
      bool isDisplayVipFeatureExists = currentVisitor.getFlag("do_not_exists", false).exists();
    });
  }

Managing visitor consent

The Visitor class provides a method to let you manage visitor consent for data privacy usage. When false the activation and hits will be disabled.

//////////////////////////////////////
/////// Manage visitor consent ///////
//////////////////////////////////////

// Create visitor with no consent
var visitor = Flagship.newVisitor(visitorIdController.text, visitorContext, hasConsented:false);
// Set the consent to true on run time
visitor.setConsent(true);

Hit Tracking

This section helps send tracking and learn how to build hits in order to track campaign goals.

The different types of Hits are:

They must all be built and sent with the following method of the visitor instance:

Future<void> SendHit(hit HitProtocol)

Common parameters

These parameters can be sent with any type of hit.

ParameterTypeDescription
userIpStringoptional User IP
screenResolutionStringoptional Screen Resolution.
userLanguageStringoptional User Language
sessionNumberintoptional Session Number

Hit types

Screen

This hit should be sent each time a visitor arrives on a new interface.

Hit parameterTypeRequiredDescription
locationStringYesName of the screen
//////////////////////////
/////// Screen hit ///////
//////////////////////////

var visitor = Flagship.getCurrentVisitor();
// Send screen hit 
visitor?.sendHit(Screen(location: "My page"));

Transaction

This hit should be sent when a user complete a Transaction.

Hit ParameterTypeRequiredDescription
transactionIdStringYesTransaction unique identifier.
affiliationStringYesTransaction name. Name of the goal in the reporting.
revenuedouble?NoTotal revenue associated with the transaction. This value should include any shipping or tax costs.
shippingdouble?NoSpecifies the total shipping cost of the transaction.
shippingMethodString?NoSpecifies the shipping method of the transaction.
taxdouble?NoSpecifies the total taxes of the transaction.
currencyString?NoSpecifies the currency used for all transaction currency values. Value should be a valid ISO 4217 currency code.
paymentMethodString?NoSpecifies the payment method for the transaction.
itemCountint?NoSpecifies the number of items for the transaction.
couponCodeString?NoSpecifies the coupon code used by the customer for the transaction.
///////////////////////////////
/////// Transaction hit ///////
///////////////////////////////

var visitor = Flagship.getCurrentVisitor();
visitor?.sendHit(Transaction(
  transactionId   : "YOUR_TRANSACTION_ID",
  affiliation     : "GOAL_NAME", // The goal name set in Flagship campaign
  revenue         : 100,
  shipping        : 10,
  tax             : 5,
  currency        : "EUR",
  couponCode      : "discount",
  paymentMethod   : "Card",
  shippingMethod  : "postal",
  itemCount       : 2,
));

Item

This hit is linked to a transaction. It must be sent after the corresponding transaction.

Hit ParameterTypeRequired Description
transactionIdStringYesTransaction unique identifier.
nameStringYesProduct name.
codeStringYesSpecifies the item code or SKU.
pricedouble?NoSpecifies the item price.
categoryString?NoSpecifies the item category.
quantityint?NoSpecifies the item quantity
////////////////////////
/////// Item hit ///////
////////////////////////

var visitor = Flagship.getCurrentVisitor();
visitor?.sendHit(Item(
  transactionId : "YOUR_TRANSACTION_ID",
  name                  : "item name",
  code                  : "item code",
  price                 : 10.5,
  quantity          : 5,
  category          : "item category"
));

Event

This hit can be anything you want: for example a click or a newsletter subscription.

Hit ParameterTypeRequired Description
CategoryCategoryEventYesCategory of the event ("Action_Tracking" or "User_Engagement").
ActionStringYesThe event action. Should match the goal name of the campaign
LabelStringNoLabel of the event.
ValueintNoSpecifies a value for this event. must be non-negative.
/////////////////////////
/////// Event hit ///////
/////////////////////////

var visitor = Flagship.getCurrentVisitor();
visitor?.sendHit(Event(
  action        : "Event action", // The name of the goal defined in your campaign
  category  : CategoryEvent.Action_Tracking,
  label         : "custom label",
  value         : 2
));

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