Welcome to the exciting world of data! In Flutter, most beautiful apps aren't static; they interact with information, bringing it to life on the screen. This section will equip you with the knowledge to understand where this data comes from and how to fetch it into your Flutter application.
Before we can display data, we need to understand its origins. Data can reside in various places, and knowing the difference is crucial for choosing the right fetching strategies. Here are some common data sources:
- Local Storage: This refers to data stored directly on the user's device. Think of things like user preferences, offline data, or cached information. Examples include shared preferences, SQLite databases, or file storage.
- Remote APIs (Application Programming Interfaces): This is the most common scenario for dynamic applications. Data is hosted on a server and accessed over the internet. When your app needs information, it makes a request to the API, which then sends back the requested data, typically in a structured format like JSON.
- Databases (Cloud-hosted): Similar to remote APIs, but you might interact more directly with a cloud-hosted database service (like Firebase Firestore or Supabase) that provides real-time data synchronization and querying capabilities.
- Files: Sometimes, data can be embedded within your app's assets as static files (like JSON or CSV files) that are bundled with your application. This is suitable for data that doesn't change frequently.
Now, let's talk about fetching. Fetching is the process of retrieving data from its source and making it available for your Flutter app to use. The method you use for fetching depends entirely on the data source.
For remote APIs, the most common approach involves making HTTP requests. Flutter provides excellent support for this through the http package. You'll send requests (like GET, POST, PUT, DELETE) to specific API endpoints and receive responses.