In the age of information, having quick access to weather data can be invaluable. This guide will walk you through building a simple yet robust Flutter Weather App using the OpenWeatherMap API. Ready to dive into the world of Flutter? Let’s get started!

App Overview

The weather app will showcase:

• Current weather (condition and temperature)
• 5-day weather forecast
• Search functionality to find weather by city

Understanding App Architecture

The app is composed of three main layers:

Data Layer

The data layer consists of a single HttpWeatherRepository that is responsible for fetching weather data from the OpenWeatherMap API. After fetching, the data is parsed using Freezed to create type-safe entity classes (Weather and Forecast).

For detailed insights about this architecture, consider checking out the articles:

• Flutter App Architecture: The Repository Pattern
• Flutter Project Structure: Feature-first or Layer-first?

Application Layer

This layer includes various providers that assist in fetching and caching data from the HttpWeatherRepository.

final cityProvider = StateProvider((ref) => 'London');

final currentWeatherProvider = FutureProvider.autoDispose((ref) async {
    final city = ref.watch(cityProvider);
    final weather = await ref.watch(weatherRepositoryProvider).getWeather(city: city);
    return WeatherData.from(weather);
});

final hourlyWeatherProvider = FutureProvider.autoDispose((ref) async {
    final city = ref.watch(cityProvider);
    final forecast = await ref.watch(weatherRepositoryProvider).getForecast(city: city);
    return ForecastData.from(forecast);
});

Presentation Layer

This layer holds all the widgets that interact with the data from the FutureProviders and ensure the UI reflects the current application state (loading, error, or success).

Understanding the Code: An Analogy

Imagine you’re planning a dinner party. First, you need to know what ingredients you have (Data Layer), then you decide on a menu and cooking schedule (Application Layer), and lastly, you serve the food to your guests (Presentation Layer). Just like dinner planning, the app structure breaks down complex tasks into manageable layers, making development smoother and more organized.

Packages You’ll Need

This app utilizes several essential packages:

• Riverpod for state management
• Freezed for code generation
• http for REST API communication
• cached_network_image for image caching
• mocktail for testing

Getting Started with the OpenWeatherMap API

To use the OpenWeatherMap API, you need to register and obtain your API key. This key can either be set via --dart-define or placed in lib/src/api/api_keys.dart.

Troubleshooting

If you encounter issues:

• Ensure your API key is correctly set and valid.
• Check if you have the required packages installed and up-to-date.
• Pay attention to any console errors during API calls; they can provide useful debugging information.

For further assistance, don’t hesitate to ask questions online, or for more insights, updates, or to collaborate on AI development projects, stay connected with fxis.ai.

Final Thoughts

At fxis.ai, we believe that such advancements are crucial for the future of AI, as they enable more comprehensive and effective solutions. Our team is continually exploring new methodologies to push the envelope in artificial intelligence, ensuring that our clients benefit from the latest technological innovations.