Question 195766 in Flutter Question posted in
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Future API Call Flutter

Im trying to create an simple Network class on dart, to centralize all my calls to an specific API.

So i create an Service class, and create an mock and a get function using Dio.


import 'package:dio/dio.dart';
import 'package:flutter/services.dart';
import 'package:playground/home/model/home.dart';
import 'package:playground/network/base/safe_call.dart';
import 'dart:convert';
import '../../base/api_result.dart';
import '../../base/network_error.dart';


class HomeServices {
  final Dio _dio;

  HomeServices(this._dio);

  Future<Object> getHome() async {
    try {
      final response = await Dio().get("https://jsonplaceholder.typicode.com/posts");
      // Parse the response data into a `Home` object
      final homeData = Home.fromJson(response.data);
      return homeData;
    } catch (e) {
      return networkError(e);
    }
  }

  Future<Home> mockHome() async {
    try {
      String response = await rootBundle.loadString('assets/home.json');
      Map<String, dynamic> homeMap = await jsonDecode(response);
      var homeData = Home.fromJson(homeMap);
      return homeData;
    } catch (e) {
      return Home(List.empty(), List.empty());
    }
  }
}

And another class called APIClient, to center all my services:

import 'package:playground/network/services/home/home_services.dart';
import 'package:pretty_dio_logger/pretty_dio_logger.dart';

class ApiClient {
  late final Dio _dio = Dio()..interceptors.add(PrettyDioLogger(
  request: true,
  requestHeader: true,
  requestBody: true,
  responseHeader: false
  ));

  late HomeServices homeServices = HomeServices(_dio);
}

and inside my repository class, i think i should use like this:

  Future<Home> readJson() async {
    await apiClient.homeServices.mockHome().then((value) {
      return value;
    }).catchError((error) {
      return error;
    });
  }

But im getting the error:

: Error: A non-null value must be returned since the return type 'Home' doesn't allow null.
carousel_repository.dart:13
- 'Home' is from 'package:playground/home/model/home.dart' ('lib/home/model/home.dart').
home.dart:1
  Future<Home> readJson() async {

Not really sure on whats wrong with the call.

Tags:

3

Answers


  1. 0

    Not sure about my answer, but I feel readJson() should return Home since the return is only Home object.

    If function return is Future<Home> then we can return the response from apiClient.

      Future<Home> readJson() async {
    // await apiClient.homeServices.mockHome().then((value) {
    //   return value;
    // }).catchError((error) {
    //   return error;
    // });
    final response = await apiClient.homeServices.mockHome();
    return response;
  }
    Login or Signup to reply.
  2. 0

    Try this :

    Future<Home>? readJson() async {
    await apiClient.homeServices.mockHome().then((value) {
      return value;
    }).catchError((error) {
      return error;
    });
  }
    Login or Signup to reply.
  3. 0

    The error you’re encountering is because the readJson() method is expected to return a non-null value of type Home, but your current implementation does not provide a return value in all code paths.

    Try this:

    Future<Home> readJson() async {
  try {
    return await apiClient.homeServices.mockHome();
  } catch (error) {
    throw Exception(error);
  }
}
    Login or Signup to reply.
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