Installing Kotlin SDK

11min
You can integrate the Ditto SDK into Kotlin projects to develop native apps for the Android platform. 
For a complete overview of the platforms, transports, and devices the Kotlin SDK supports, see Compatibility with Kotlin﻿.
To install the Kotlin SDK and start syncing offline:
1
Confirm that you meet the minimum requirements. (Prerequisites﻿)
2
Prepare your environment for Ditto. (Setting Up Your Environment﻿)
3
Configure your app permissions. (Setting Up Permissions﻿)
4
Authenticate with the Big Peer and then start syncing offline. (Integrating and Initializing﻿)
Prerequisites
Following are the minimum requirements that must be met before attempting to install Ditto.
Android version 6.0 (Marshmallow)
minSdk version 23.0
compileSdk version 31.0
Java Development Kit (JDK) version 11.0
Setting Up Your Environment
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Setting Up Permissions
﻿
Android Manifest Permissions
The Ditto Android SDK includes a set of permissions that are required to use all
the device features necessary to enable sync. The permissions below will be
automatically merged into your app's final manifest.
AndroidManifest.xml
<manifest
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:android="http://schemas.android.com/apk/res/android">

<uses-permission android:name="android.permission.BLUETOOTH"
    android:maxSdkVersion="30" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"
    android:maxSdkVersion="30" />
<uses-permission android:name="android.permission.BLUETOOTH_ADVERTISE"
    tools:targetApi="s" />
<uses-permission android:name="android.permission.BLUETOOTH_CONNECT"
    tools:targetApi="s" />
<uses-permission android:name="android.permission.BLUETOOTH_SCAN"
    android:usesPermissionFlags="neverForLocation"
    tools:targetApi="s" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"
    android:maxSdkVersion="32" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"
    android:maxSdkVersion="30" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_MULTICAST_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
<uses-permission android:name="android.permission.NEARBY_WIFI_DEVICES"
    android:usesPermissionFlags="neverForLocation"
    tools:targetApi="tiramisu" />
<manifest
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:android="http://schemas.android.com/apk/res/android">

<uses-permission android:name="android.permission.BLUETOOTH"
    android:maxSdkVersion="30" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN"
    android:maxSdkVersion="30" />
<uses-permission android:name="android.permission.BLUETOOTH_ADVERTISE"
    tools:targetApi="s" />
<uses-permission android:name="android.permission.BLUETOOTH_CONNECT"
    tools:targetApi="s" />
<uses-permission android:name="android.permission.BLUETOOTH_SCAN"
    android:usesPermissionFlags="neverForLocation"
    tools:targetApi="s" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"
    android:maxSdkVersion="32" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"
    android:maxSdkVersion="30" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_MULTICAST_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
<uses-permission android:name="android.permission.NEARBY_WIFI_DEVICES"
    android:usesPermissionFlags="neverForLocation"
    tools:targetApi="tiramisu" />
﻿
The tools:targetApi attribute causes the permission to only be requested on
devices running the specified API level or higher. This avoids errors in older
OS versions that do not recognize the permission.
The android:maxSdkVersion attribute causes permission to only be requested
on devices running the specified SDK level or lower. This avoids asking for more
permissions than Ditto needs; however, it will prevent your app from being able
to request permission on devices running a newer OS version. 
To opt out of this behavior and request permission on all OS versions, see the following
snippet:
Location Permission Override
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"
    tools:remove="android:maxSdkVersion" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"
    tools:remove="android:maxSdkVersion" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"
    tools:remove="android:maxSdkVersion" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"
    tools:remove="android:maxSdkVersion" />
﻿
Note that you may need to add the xmlns:tools="http://schemas.android.com/tools"
namespace attribute to your app's root <manifest> tag as shown in the
AndroidManifest.xml example above.
This will configure your app's build to ignore the android:maxSdkVersion
attribute in our SDK allowing the permission to be requested on any SDK version.
This technique can be used to tweak any permissions to your liking.
For more details, see the documentation for the Bluetooth and WiFi Aware permissions in the Android Documentation.
Runtime Permissions
﻿
The DittoSyncPermissions object requires a Context. You can get the context by invoking getApplicationContext(), getContext(), getBaseContext() or this when in a class that extends from Context, such as the Application, Activity, Service, and IntentService Classes.
Kotlin
fun checkPermissions() {
    val missing = DittoSyncPermissions(this).missingPermissions()
    if (missing.isNotEmpty()) {
        this.requestPermissions(missing, 0)
    }
}
fun checkPermissions() {
    val missing = DittoSyncPermissions(this).missingPermissions()
    if (missing.isNotEmpty()) {
        this.requestPermissions(missing, 0)
    }
}
﻿
Alternatively, requireActivity() is a way to force the code to only work on a Fragment that has a Context.
Kotlin
fun checkPermissions() {
    val activity = requireActivity()
    val missing = DittoSyncPermissions(activity).missingPermissions()
    if (missing.isNotEmpty()) {
        activity.requestPermissions(missing, 0)
    }
}
fun checkPermissions() {
    val activity = requireActivity()
    val missing = DittoSyncPermissions(activity).missingPermissions()
    if (missing.isNotEmpty()) {
        activity.requestPermissions(missing, 0)
    }
}
﻿
﻿
Kotlin
override fun onRequestPermissionsResult(
    requestCode: Int,
    permissions: Array<out String>,
    grantResults: IntArray
) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults)
    // Regardless of the outcome, tell Ditto that permissions maybe changed
    ditto?.refreshPermissions()
}
override fun onRequestPermissionsResult(
    requestCode: Int,
    permissions: Array<out String>,
    grantResults: IntArray
) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults)
    // Regardless of the outcome, tell Ditto that permissions maybe changed
    ditto?.refreshPermissions()
}
﻿
﻿
Integrating and Initializing
1
Add Ditto to your application.
We recommend placing this in your Application.onCreate method. Note that the Context you want to reference here is the Application level Context, rather than whatever Activity you might happen to be instantiating the Ditto instance from initially. 
This is because you need to ensure that your app is keeping a single Ditto instance alive for the entire lifetime of the application so it is not going out of scope or getting garbage collected.
Kotlin
try {
    val androidDependencies = DefaultAndroidDittoDependencies(context)
    val identity = DittoIdentity.OnlinePlayground(
        androidDependencies,
        appId = "REPLACE_ME_WITH_YOUR_APP_ID",
        token = "REPLACE_ME_WITH_YOUR_PLAYGROUND_TOKEN"
    )
    DittoLogger.minimumLogLevel = DittoLogLevel.DEBUG
    ditto = Ditto(androidDependencies, identity)
    ditto.startSync()
} catch (e: DittoError) {
    Log.e("Ditto error", e.message!!)
}
try {
    val androidDependencies = DefaultAndroidDittoDependencies(context)
    val identity = DittoIdentity.OnlinePlayground(
        androidDependencies,
        appId = "REPLACE_ME_WITH_YOUR_APP_ID",
        token = "REPLACE_ME_WITH_YOUR_PLAYGROUND_TOKEN"
    )
    DittoLogger.minimumLogLevel = DittoLogLevel.DEBUG
    ditto = Ditto(androidDependencies, identity)
    ditto.startSync()
} catch (e: DittoError) {
    Log.e("Ditto error", e.message!!)
}
﻿
2
Replace YOUR_APP_ID and YOUR_PLAYGROUND_TOKEN with your access credentials available from the portal. 
For instructions on how to obtain your access credentials, see Onboarding﻿. For an introduction to authentication in Ditto, see Ditto Basics > Authentication and Initialization﻿.
﻿
Updated 29 Nov 2023
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TABLE OF CONTENTS
Prerequisites
Setting Up Your Environment
Setting Up Permissions
Android Manifest Permissions
Runtime Permissions
Integrating and Initializing