Get Started for Android

To build your Flutter mobile application with Android as your primary development target with the Flutter SDK, you will need to set up the environment required for developing an Android app in Catalyst.

Prerequisites and Minimum Supported Environments

Before you begin working with your Flutter app on the Android platform, you must ensure that you meet the following prerequisites and configure these minimum supported environments:

• Create a Flutter project in Android Studio or any supported IDE

• Ensure that your Android project meets these minimum supported environments:

  • OS- Android API Level 21 (Lollipop 4.4)
  • Kotlin- 1.3.20
  • Gradle- 3.4.0

• Set up a device or an emulator in your IDE for running your app

You can register your app with Catalyst and download the configuration file that is provided tailored to your app. You must include this configuration file in your Android app’s structure, as it will contain the definitions of certain properties required for your app to function properly.

Setup

After you meet the prerequisites for the Flutter and Android setups, follow these steps to set up and integrate the Android package with your app.

Step 1: Register your Android app with Catalyst

You can begin by creating a package for the Android app in Catalyst to register it, and downloading its unique configuration file.

1. Click the Settings icon from your Catalyst console in your project.

2. Navigate to Developer Tools under Project Settings in the settings menu, then click on the Android tile. Alternatively, you can click the Add Package button below.

3. Enter a package name that will identify it uniquely. Provide the URL to redirect the end-user to after they login to the app, as the Redirect URL. The values that you enter here will be auto-filled in the configuration file.

4. Click Create to create the mobile SDK package.

5. The console will then display a window from where you can download the configuration file. Click Download to download the file.

The file will be downloaded with all the required configurations. The properties in this file are explained in the next step.

Step 2: Import the Configuration File in Your Android Project

Catalyst provides two work environments to develop and build your applications in: a Development sandbox and a live Production environment. You can learn more about them from the Environments help page.

When you create a package in the console, only the development environment’s configuration file will be available for download initially, irrespective of the environment you are working in currently. You can choose to download the configuration file from the console for any environment any time, once the package has been created.

The configuration files of each environment would be named as:

• Development: app_configuration_development.properties
• Production: app_configuration_production.properties

Based on the environment that you are working in, you must download and add the appropriate file to your Android app’s structure. To obtain a production environment configuration file, you must deploy your project to production first and then download the file from the Developer Tools settings section.

The configuration file must be added to the assets directory of your Android app module. Typically, the assets folder is created in the app/src/main directory.

Refer to the official Android documentation for detailed help on Android app modules.

Properties of the app_configuration_development.properties/ app_configuration_production.properties File

The app configuration file defines the properties mentioned in the table below. All these values except the request headers are automatically populated, based on your project’s details or the default standards.

Step 3: Configure App Login Redirection

When a user logs in to your app successfully, they will be redirected to your app’s home screen. This user login and redirection is handled by the Catalyst SDK.

To ensure that this redirection is handled properly, include the URL schema given below in the strings.xml file of your Android app:

    

        
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         <string name="url_scheme">{redirection_url}</string>

    

The strings.xml file is automatically created when you create the Android project. You can find it by navigating to app/src/main/res/values in your app’s structure. The file will already contain the string definition for your app name. Include this string along with it.

You must pass the Redirection URL that you configured while creating the package for your app in Catalyst, in place of redirection_url in this code.

You must also add ‘://’ at the end of your app’s URL scheme. For example, if the url is ‘https://www.zylker.com/shipments/register.js’, then you must pass the value of the url_scheme string as ‘https://www.zylker.com/shipments/register.js:// '

Step 4: Set Required Permissions

Catalyst SDK requires the following app permissions to be enabled, to ensure that your app functions seamlessly and to provide a smooth user experience:

• INTERNET: To execute Catalyst APIs
• ACCESS_NETWORK_STATE: To handle network failures

To enable these permissions, you must declare them in the AndroidManifest.xml file, as shown below:

    

        
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         <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.INTERNET"/>

    

You can find the the AndroidManifest.xml file by navigating to app/src/main in your app’s structure.

The setup for building a Flutter app with Android as the primary development target is now ready. You can now proceed to implementing Catalyst Flutter SDK in your app.