flutter_config 0.0.1

Config Variables for your Flutter Apps.

Config Variables for your Flutter apps

Plugin that exposes environment variables to your Dart code in Flutter as well as to your native code in iOS and Android.

Inspired by react-native-config

Basic Usage

Create a new file .env in the root of your Flutter app:

API_URL=https://myapi.com
FABRIC_ID=abcdefgh

load all environment varibles in main.dart

import 'package:flutter_config/flutter_config.dart';

void main() async {

  await FlutterConfig.loadEnvVariables();

  runApp(MyApp());
}

Now you can access your environment varibles anywhere in your app.

import 'package:flutter_config/flutter_config.dart';

FlutterConfig.get('FABRIC_ID') // returns 'abcdefgh'

Keep in mind this module doesn't obfuscate or encrypt secrets for packaging, so do not store sensitive keys in .env. It's basically impossible to prevent users from reverse engineering mobile app secrets, so design your app (and APIs) with that in mind.

Getting Started

Install the latest version of the plugin

Additional step for Android

You need to manually apply a plugin to your app, from android/app/build.gradle:

Right below apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"

add the following line:

apply from: project(':flutter_config').projectDir.getPath() + "/dotenv.gradle"

Native Usage

Android

Config variables set in .env are available to your Java or Kotlin classes via BuildConfig:

fun getApiClient(): HttpURLConnection {
    val url = URL(BuildConfig.API_URL);
    // ...
}

You can also read them from your Gradle configuration:

defaultConfig {
    applicationId project.env.get("APP_ID")
}

And use them to configure libraries in AndroidManifest.xml and others:

<meta-data
  android:name="com.google.android.geo.API_KEY"
  android:value="@string/GOOGLE_MAPS_API_KEY" />

All variables are strings, so you may need to cast them. For instance, in Gradle:

versionCode project.env.get("VERSION_CODE").toInteger()

Once again, remember variables stored in .env are published with your code, so DO NOT put anything sensitive there like your app signingConfigs.

iOS

Read variables declared in .env from your Obj-C classes like:

// import header
#import "FlutterConfigPlugin.h"

// then read individual keys like:
NSString *apiUrl = [FlutterConfigPlugin envFor:@"API_URL"];

// or just fetch the whole config
NSDictionary *config = [FlutterConfigPlugin env];

Different environments

Save config for different environments in different files: .env.staging, .env.production, etc.

Android

The same environment variable can be used to assemble releases with a different config:

$ cd android && ENVFILE=.env.staging ./gradlew assembleRelease

Alternatively, you can define a map in build.gradle associating builds with env files. Do it before the apply from call, and use build cases in lowercase, like:

project.ext.envConfigFiles = [
    debug: ".env.development",
    release: ".env.production",
    anothercustombuild: ".env",
]

apply from: project(':flutter_config').projectDir.getPath() + "/dotenv.gradle"

iOS

The basic idea in iOS is to have one scheme per environment file, so you can easily alternate between them.

Start by creating a new scheme:

• In the Xcode menu, go to Product > Scheme > Edit Scheme
• Click Duplicate Scheme on the bottom
• Give it a proper name on the top left. For instance: "Myapp (staging)"

Then edit the newly created scheme to make it use a different env file. From the same "manage scheme" window:

• Expand the "Build" settings on left
• Click "Pre-actions", and under the plus sign select "New Run Script Action"
• Where it says "Type a script or drag a script file", type:

  echo ".env.staging" > /tmp/envfile   # replace .env.staging for your file
  

This is still a bit experimental and dirty – let us know if you have a better idea on how to make iOS use different configurations opening a pull request or issue!