Android SDK

This guide provides detailed information about our Android SDK. All of our SDKs are open source. Go to our Android SDK GitHub repository to see the source code.

Language Support

This library is compatible with Android SDK versions 15 and later (4.0.3 Ice Cream Sandwich).

Initialization

To get started, set up Split in your code base with the following two steps.

1. Import the SDK into your project

You can import the SDK into your project using the following line:

implementation 'io.split.client:android-client:2.7.2'

2. Instantiate the SDK and create a new Split client

The first time the SDK is instantiated, it starts background tasks to update an in-memory cache and in-storage cache with small amounts of data fetched from Split servers. This process can take up to a few hundred milliseconds depending on the size of the data.

If the SDK is asked to evaluate which treatment to show to a customer for a specific split while it is in this intermediate state, it may not have the data necessary to run the evaluation. In this circumstance, the SDK does not fail, rather, it returns the control treatment.

After the first initialization, the fetched data is stored. Further initializations fetch data from that cache and the configuration is immediately available. We recommend instantiating the SDK once as a singleton and reusing it throughout your application.

Include the API key for the environment that you are setting up the SDK for. The API key is available on your Admin Settings page, on the APIs keys tab. Select "client side" type. This is a special type of API token with limited privileges to be used for the untrustable world of browsers or mobile clients. Learn more about API keys.

import io.split.android.client.SplitClient;
import io.split.android.client.SplitClientConfig;
import io.split.android.client.SplitFactory;
import io.split.android.client.SplitFactoryBuilder;
import io.split.android.client.api.Key;

//API Key
String apikey = "YOUR_API_KEY";

// Build SDK configuration by default
SplitClientConfig config = SplitClientConfig.builder()
  .build();

// Create a new user key to be evaluated
String matchingKey = "key";
Key k = new Key(matchingKey);

// Create factory
SplitFactory splitFactory = SplitFactoryBuilder.build(apikey, k, config, getApplicationContext());

// Get Split Client instance
SplitClient client = splitFactory.client();

Using the SDK

The following explains how to use this SDK.

Basic usage

To make sure the SDK is properly loaded before asking it for a treatment, you should wait until the SDK is ready as shown below. We set the client to listen for the SDK_READY event triggered by the SDK before asking for an evaluation.

Once the SKD_READY event fires, you can use the getTreatment method to return the proper treatment based on the SPLIT_NAME you pass and the key you passed when instantiating the SDK.

From there, you need to use an if-else-if block as shown below and plug the code in for the different treatments that you defined in the Split UI. Make sure to remember the final else branch in your code to handle the client returning control.

client.on(SplitEvent.SDK_READY, new SplitEventTask() {
  String treatment = client.getTreatment("SPLIT_NAME");

  if (treatment.equals("on")) {
      // insert code here to show on treatment
  } else if (treatment.equals("off")) {
      // insert code here to show off treatment
  } else {
      // insert your control treatment code here
  }
});

client.on(SplitEvent.SDK_READY_TIMED_OUT, new SplitEventTask() {
  // handle for timeouts here
}  

Also, a SDK_READY_FROM_CACHE event is available, which allows to be aware of when the SDK has loaded data from cache. This way, it is ready to evaluate splits using those locally cached definitions.

client.on(SplitEvent.SDK_READY_FROM_CACHE, new SplitEventTask() {
  String treatment = client.getTreatment("SPLIT_NAME");

  if (treatment.equals("on")) {
      // insert code here to show on treatment
  } else if (treatment.equals("off")) {
      // insert code here to show off treatment
  } else {
      // insert your control treatment code here
  }
});

Shutdown

Before letting your app shut down, call destroy() as it gracefully shuts down the Split SDK by stopping all background threads, clearing caches, closing connections, and flushing the remaining unpublished impressions. Executing the client.destroy() method into onDestroy callback of your MainActivity is a good practice.

client.destroy()

After destroy() is called, any subsequent invocations to the client.getTreatment() or manager methods result in control or empty list respectively.

Multiple evaluations at once

In some instances, you may want to evaluate treatments for multiple splits at once. Use the GetTreatments method of the Split client to do this. Simply pass a list of the split names you want treatments for and the method returns an object with the results.

List<String> splitNames = Lists.newArrayList("SPLIT_NAME_1", "SPLIT_NAME_2");
Map<String, String> treatments = client.getTreatments(splitNames, null);

// treatments will have the following form:
// {
//   "SPLIT_NAME_1": "on",
//   "SPLIT_NAME_2": "visa"
// }

Attribute syntax

To target based on custom attributes, the SDK's getTreatment method needs to be passed an attribute map at runtime.

In the example below, we are rolling out a split to users. The provided attributes plan_type, registered_date, permissions, paying_customer, and deal_size are passed to the getTreatment call. These attributes are compared and evaluated against the attributes used in the Rollout plan as defined in the Split Web console to decide which treatment is assigned to this key.

The getTreatment method supports five types of attributes: strings, numbers, dates, booleans, and sets. The proper data type and syntax for each are:

• Strings: Use type String.
• Numbers: Use type java.lang.Long or java.lang.Integer.
• Dates: Express the value in milliseconds since epoch. In Java, milliseconds since epoch is of type java.lang.Long. For example, the value for the registered_date attribute below is System.currentTimeInMillis(), which is a long.
• Booleans: Use type java.lang.boolean.
• Sets: Use type java.util.Collection.

import java.util.Map;
import java.util.HashMap;
import java.util.Date;

Map<String, Object> attributes = new HashMap<String, Object>();
attributes.put("plan_type", "growth");
attributes.put("registered_date", System.currentTimeMillis());
attributes.put("deal_size", 1000);
attributes.put("paying_customer", true);
String[] perms = {"read", "write"};
attributes.put("permissions",perms);

// See client initialization above
String treatment = client.getTreatment("SPLIT_NAME", attributes);

if (treatment.equals("on")) {
    // insert on code here
} else if (treatment.equals("off")) {
    // insert off code here
} else {
    // insert control code here
}

Get Treatments with Configurations

To leverage dynamic configurations with your treatments, you should use the getTreatmentWithConfig method.

This method will return an object containing the treatment and associated configuration.

The config element will be a stringified version of the configuration JSON defined in the Split web console. If there is no configuration defined for a treatment, the SDK will return null for the config parameter.

This method takes the exact same set of arguments as the standard getTreatment method. See below for examples on proper usage:

SplitResult result = cli.getTreatmentWithConfig("new_boxes", attributes);
Gson gson = new Gson();
Map map = gson.fromJson(result.config(), Map.class);
String treatment = result.treatment();

If you need to get multiple evaluations at once, you can also use the getTreatmentsWithConfig. The method takes the exact same arguments as the getTreatments method but just returns a mapping of split names to splitResults instead of strings. Example usage below.

List<String> splitNames = Lists.newArrayList("SPLIT_NAME_1", "SPLIT_NAME_2");
Map<String, String> treatments = client.getTreatmentsWithConfig(splitNames, null);

// treatments will have the following form:
// {
//   "SPLIT_NAME_1": { "treatment": "on", "config": "{ \"color\":\"red\" }" },
//   "SPLIT_NAME_2": { "treatment": "visa", "config": "{ \"color\":\"red\" }" }
// }

Track

Use the track method to record any actions your customers perform. Each action is known as an event and corresponds to an event type. Calling track through one of our SDKs or via the API is the first step to getting experimentation data into Split and allows you to measure the impact of your splits on your users' actions and metrics.

Learn more about using track events in Split.

In the examples below, you can see that the .track() method can take up to four arguments. The proper data type and syntax for each are:

• TRAFFIC_TYPE: The traffic type of the key in the track call. The expected data type is String. You can only pass values that match the names of traffic types that you have defined in your instance of Split.
• EVENT_TYPE: The event type that this event should correspond to. The expected data type is String. Full requirements on this argument are:
  • Contains 80 characters or fewer.
  • Starts with a letter or number.
  • Contains only letters, numbers, hyphen, underscore, or period.
  • This is the regular expression we use to validate the value: [a-zA-Z0-9][-_.:a-zA-Z0-9]{0,79}
• VALUE: (Optional) The value to be used in creating the metric. This field can be sent in as null or 0 if you intend to purely use the count function when creating a metric. The expected data type is Float.
• PROPERTIES: (Optional) A Map of key value pairs that can be used to filter your metrics. Learn more about event property capture here. Split currently supports three types of properties: strings, numbers, and booleans.

The track method returns a boolean value of true or false to indicate whether or not the SDK was able to successfully queue the event to be sent back to Split's servers on the next event post. The SDK will return false if the current queue size is equal to the config set by eventsQueueSize or if an incorrect input to the track method has been provided.

In the case that a bad input has been provided, you can read more about our SDK's expected behavior here

// Event without a value
boolean trackEvent = client.track("TRAFFIC_TYPE", "EVENT_TYPE");
// Example
boolean trackEvent = client.track("user", "page_load_time");

// Associate value to an event
boolean trackEvent = client.track("TRAFFIC_TYPE", "EVENT_TYPE", VALUE);
// Example  
boolean trackEvent = client.track("user", "page_load_time", 83.334);

// If you would like to send an event but you've already defined the traffic type in the config of the client
boolean trackEvent = client.track("EVENT_TYPE");
// Example
boolean trackEvent = client.track("page_load_time");

// If you would like to associate a value to an event and you've already defined the traffic type in the config of the client
boolean trackEvent = client.track("EVENT_TYPE", VALUE);
// Example  
boolean trackEvent = client.track("page_load_time", 83.334);

// If you would like to associate a value and properties to an event
boolean trackEvent = client.track("key", "TRAFFIC_TYPE", "EVENT_TYPE", VALUE, {PROPERTIES});
// Example  
HashMap<String, Object> properties = new HashMap<>();
properties.put("package", "premium");
properties.put("admin", true);
properties.put("discount", 50);

boolean trackEvent = client.track("john@doe.com", "user", "page_load_time", 83.334, properties);

// If you would like to associate just properties to an event
boolean trackEvent = client.track("key", "TRAFFIC_TYPE", "EVENT_TYPE", null, {PROPERTIES});
// Example  
HashMap<String, Object> properties = new HashMap<>();
properties.put("package", "premium");
properties.put("admin", true);
properties.put("discount", 50);

boolean trackEvent = client.track("john@doe.com", "user", "page_load_time", null, properties);

Configuration

The SDK has a number of knobs for configuring performance. Each knob is tuned to a reasonable default. However, you can override the value while instantiating the SDK. The parameters available for configuration are shown below.

To set each of the parameters defined above, use the syntax below.

import io.split.android.client.*;
import java.util.Arrays;

SplitFilter splitFilter = SplitFilter.byName(Arrays.asList("SPLIT_NAME_1", "SPLIT_NAME_2"));

SplitClientConfig config = SplitClientConfig.builder()
                            .impressionsRefreshRate(60)
                            .connectionTimeout(15000)
                            .readTimeout(15000)
                            .syncConfig(SyncConfig.builder()
                                .addSplitFilter(splitFilter)
                                .build())
                            .build();

//API Key
String apikey = "YOUR_API_KEY";

// Create a new user key to be evaluated
String matching = "key";
String bucketingKey = null;
Key k = new Key(matchingKey,bucketingKey);

// Create factory
SplitFactory splitFactory = SplitFactoryBuilder.build(apikey, k, config, getApplicationContext());

// Get Split Client instance
SplitClient client = splitFactory.client();

Localhost mode

Features start their life on one developer's machine. A developer should be able to put code behind splits on their development machine without the SDK requiring network connectivity. To achieve this, the Split SDK can be started in localhost mode (aka off-the-grid mode). In this mode, the SDK neither polls nor updates Split servers. Instead, it uses an in-memory data structure to determine what treatments to show to the logged in customer for each of the features.

To use the SDK in localhost mode, replace the API Key with localhost, as shown in the example below:

Since version 2.2.0, our SDK supports a new type of localhost split definition file, using the YAML format. This new format allows the user to map different keys to different treatments within a single split, and also add configurations to them. The new format is a list of single-key maps (one per mapping split-keys-config), defined as follows:

# - feature_name:
#     treatment: "treatment_applied_to_this_entry"
#     keys: "single_key_or_list"
#     config: "{\"desc\" : \"this applies only to ON treatment\"}"

- my_feature:
    treatment: "on"
    keys: "key"
    config: "{\"desc\" : \"this applies only to ON treatment\"}"
- some_other_feature:
    treatment: "off"
- my_feature:
    treatment: "off"
- other_feature:
    treatment: "off"
    keys: ["key_1", "key_2"]
    config: "{\"desc\" : \"this overrides multiple keys and returns off treatment for those keys\"}"

In the example above, we have three entries:

• The first entry defines that for split my_feature, the key key will return the treatment on and the on treatment will be tied to the configuration {"desc" : "this applies only to ON treatment"}.
• The second entry defines that the feature some_other_feature will always return the off treatment and no configuration.
• The third entry defines that my_feature will always return off for all keys that don't match another entry (in this case, any key other than key).
• The fourth entry shows an example on how to override a treatment for a set of keys.

In this mode, the SDK loads the yaml file from a resource bundle file at the assets' project src/main/assets/splits.yaml.

import io.split.android.client.SplitClient;
import io.split.android.client.SplitFactoryBuilder;
import io.split.android.client.api.Key;

// Create a new user key to be evaluated
String matching = "key";
Key k = new Key(matchingKey);

SplitClient client = SplitFactoryBuilder.build("localhost", k, getApplicationContext()).client();

If a split.yaml or split.yml is not found in assets, Split SDK maintains backward compatibility by trying to load the legacy file (split.properties), now deprecated.

The format of this file is a properties file as key-value line. The key is the split name, and the value is the treatment name. Here is a sample split.properties file.

# this is a comment

# sdk.getTreatment(*, reporting_v2) will return 'on'
reporting_v2=on

double_writes_to_cassandra=off

new-navigation=v3

Manager

Use the Split Manager to get a list of features available to the Split client.

To instantiate a Manager in your code base, use the same factory that you used for your client.

SplitFactory splitFactory = SplitFactoryBuilder.build("YOUR_API_KEY");
SplitManager manager = splitFactory.manager();

The Manager then has the following methods available.

/**
 * Retrieves the Splits that are currently registered with the
 * SDK.
 *
 * @return a List of SplitView or empty.
 */
List<SplitView> splits();

/**
 * Returns the Splits registered with the SDK of this name.
 *
 * @return SplitView or null
 */
SplitView split(String SplitName);

/**
 * Returns the names of features (or Splits) registered with the SDK.
 *
 * @return a List of String (Split Feature Names) or empty
 */
List<String> splitNames();

The SplitView object referenced above has the following structure.

public class SplitView {
    public String name;
    public String trafficType;
    public boolean killed;
    public List<String> treatments;
    public long changeNumber;
}

Listener

Split SDKs send impression data back to Split servers periodically and as a result of evaluating splits. To additionally send this information to a location of your choice, define and attach an impression listener.

The SDK sends the generated impressions to the impression listener right away. As a result, be careful while implementing handling logic to avoid blocking the main thread. Generally speaking, you should create a separate thread to handle incoming impressions (see the snippet below).

SplitClientConfig config = SplitClientConfig.builder()
                        .impressionListener(new MyImpressionListener())
                        .build();

class MyImpressionListener implements ImpressionListener {
    @Override
    public void log(Impression impression) {
        // Do something on UI thread
        new Thread(new Runnable() {
            public void run() {
                // Do something in another thread (use this most of the time!)
            }
        }).start();
    }

    @Override
    public void close() {
    }
}

Flush

The flush() method sends the data stored in memory (impressions and events) to Split cloud and clears the successfully posted data. If a connection issue is experienced, the data will be sent on the next attempt.
If you want to flush all pending data when your app goes to background, a good place to call this method would be the onPause callback of your MainActivity.

client.flush()

Advanced: Subscribe to events

You can listen for four different types of events from the SDK.

• SDK_READY_FROM_CACHE - The SDK is ready to evaluate using the locally cached data (which might be stale). If there is data in the cache, this event will be emitted almost immediately since access to the local cache is fast. Otherwise it won't fire.
• SDK_READY fires when the SDK is ready to be used and has the most up-to-date version of your rollout plans.
• SDK_READY_TIMED_OUT fires if there is no last known configuration in disk cache, and the SDK could not acquire the information from our servers after a given period of time, determined by ready in the SplitClientConfig. When this event fires, it doesn't mean the SDK initialization is interrupted. The SDK_READY may still fire at a later time if or when the SDK finishes downloading the necessary information from the servers. This may happen with slow connections or environments which have many splits, segments, or dynamic configurations.
• SDK_UPDATE - This event fires whenever a split or segment is changed. Use this if you want to reload your app every time you make a change in the Split Web console.

An event is simply an extension of a SplitEventTask.

public class SplitEventTask {
    public void onPostExecution(SplitClient client) { }
    public void onPostExecutionView(SplitClient client) { }
}

onPostExecution is executed in the background when the event is triggered. This step is used to perform background computation, which can take a long time.

onPostExecutionView is invoked on the UI thread after onPostExecution finishes.

The syntax to listen for an event can be seen below.

client.on(SplitEvent.SDK_READY, new SplitEventTask() {
  @Override
  public void onPostExecution(SplitClient client) {
    //Background Code in Here
  }
  @Override
  public void onPostExecutionView(SplitClient client) {
    //UI Code in Here
  }
});

// When definitions were loaded from cache
client.on(SplitEvent.SDK_READY_FROM_CACHE, new SplitEventTask() {
  @Override
  public void onPostExecution(SplitClient client) {
    //Background Code in Here
  }
  @Override
  public void onPostExecutionView(SplitClient client) {
    //UI Code in Here
  }
});

// When the SDK couldn't fetch definitions befor *config.ready* time
client.on(SplitEvent.SDK_READY_TIMED_OUT, new SplitEventTask() {
  @Override
  public void onPostExecution(SplitClient client) {
    //Background Code in Here
  }
  @Override
  public void onPostExecutionView(SplitClient client) {
    //UI Code in Here
  }
});

// When definitions have changed
client.on(SplitEvent.SDK_READY_UPDATE, new SplitEventTask() {
  @Override
  public void onPostExecution(SplitClient client) {
    //Background Code in Here
  }
  @Override
  public void onPostExecutionView(SplitClient client) {
    //UI Code in Here
  }
});