builder_ip

A Dart package that simplifies connecting Flutter apps to local emulators by providing a build-time constant with the builder's IP address.

Problem

When developing Flutter apps that interact with local emulators (e.g., Firebase Emulators), you often need to specify the emulator's IP address. While localhost works fine on the development machine, it won't work when running the app on a physical device. Manually updating the IP address every time it changes is cumbersome.

Solution

This package introduces a source code builder that automatically generates a constant with the IP address of the machine used to build the app. This allows your app to connect to emulators running on your development machine even when running on a physical device.

Usage

1. Add dependencies:

   dev_dependencies:
     build_runner: ^2.1.7
     builder_ip: ^1.0.0 # Replace with the latest version
   

2. Create build.yaml:

   targets:
     $default:
       builders:
         dart_builder_ip|builder_ip:
           generate_for:
             - lib/file_that_uses_builderIp.dart  # Replace with your file
   

3. Use the builder in your Dart code:

   import 'file_that_uses_builderIp.builder-ip.dart';
   
   void main() {
     print('Builder IP: $builderIp'); 
     // Use builderIp to connect to your emulator
   }
   

Example with Firebase Emulators

import 'package:firebase_core/firebase_core.dart';
import 'package:flutter/material.dart';
import 'firebase_options.dart';

part 'main.builder-ip.dart'; // Import the generated file

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();

  await Firebase.initializeApp(
    options: DefaultFirebaseOptions.currentPlatform,
  );

  if (kDebugMode) {
    FirebaseFirestore.instance.useFirestoreEmulator(builderIp, 8080);
    await FirebaseAuth.instance.useAuthEmulator(builderIp, 9099);
  }

  // ... rest of main function
}

Remember to add main.dart to the generate_for list in your build.yaml.

How it works

The builder_ip package utilizes a code generation technique. During the build process, it identifies the IP address of the machine running the build and injects a constant named builderIp into your specified Dart file.

Benefits

• Simplified emulator connection: No more manual IP updates.
• Improved development workflow: Focus on building your app, not configuring connections.
• Enhanced portability: Easily run your app on different devices without changing code.