11

    Fetching Data from APIs

    Beginner • 19 min • Video Lesson

    Complete tasks and quiz to finish this lesson

    Video Player Placeholder (ap1DY_I_5Y8)

    Learning Objectives

    • Incorporate the HTTP package to fetch REST API network resources
    • Parse raw JSON map string feeds into typed Dart class models
    • Manage request states: show loaders, handle payloads, and catch exceptions
    • Build dynamic layouts using FutureBuilder and asynchronous checks

    What You'll Learn

    1. Adding HTTP dependencies and configuring OS network security rules
    2. Writing async GET client operations returning future collection lists
    3. Designing factory constructor mappings from JSON structures
    4. FutureBuilder integration: connectionState checks and snapshots validation

    Key Concepts

    HTTP Client
    JSON Serialization
    FutureBuilder
    Async/Await
    REST API
    Exception Handling

    Key Takeaways

    • FutureBuilder automates mapping async operation states (loading, success, error) to layouts.
    • Strongly-typed data models protect apps from parsing errors on API updates.
    • Never call fetch functions inside build() without caching, to prevent redundant network calls.

    Build Steps

    Knowledge Check

    Which widget builds screen components based on the connection states of a Future?

    What constructor parses raw dynamic map databases into structured class fields?

    What property inside AsyncSnapshot holds the returned API payload?

    Next Lesson

    12 — Local Persistence →