Flutter HTTP request to RapidAPI endpoint fails to retrieve data

[mythicMuse]

Issue with API Integration

I’m having trouble fetching data from a RapidAPI service in my Flutter app. The loading indicator keeps spinning forever which means my HTTP request is not working properly. I’ve double checked my headers and endpoint URL but still can’t get it to work.

Here’s my service class:

import 'dart:convert';
import 'package:http/http.dart' as http;
import 'package:my_app/models/listing.dart';

class DataService {
  Future<List<Listing>?> fetchListings() async {
    var endpoint = Uri.https('realty-api.p.rapidapi.com', '/properties/search',
        {"propertyId": "12345678"});

    var result = await http.get(endpoint, headers: {
      "X-RapidAPI-Host": "realty-api.p.rapidapi.com",
      "X-RapidAPI-Key": "my-api-key-here",
      "useQueryString": "true"
    });
    
    if (result.statusCode == 200) {
      return (json.decode(result.body));
    } else {
      throw Exception('API call failed');
    }
  }
}

My data model:

class Listing {
  final String name;
  final String details;
  final String category;
  final String frequency;
  final String thumbnail;
  final String mainPhoto;
  final String phone;
  final String agentName;
  final String companyName;
  final String companyLogo;
  final String furnished;
  final int virtualTours;
  final int imageCount;
  final int videos;
  final int cost;

  Listing({
    required this.mainPhoto,
    required this.details,
    required this.name,
    required this.category,
    required this.frequency,
    required this.thumbnail,
    required this.phone,
    required this.agentName,
    required this.companyName,
    required this.companyLogo,
    required this.furnished,
    required this.virtualTours,
    required this.imageCount,
    required this.videos,
    required this.cost
  });

  factory Listing.fromJson(dynamic data) {
    return Listing(
      name: data['name'] as String,
      category: data['category'] as String,
      frequency: data['frequency'] as String,
      mainPhoto: data['mainPhoto']['url'] as String,
      thumbnail: data['images'][0]['url'] as String,
      phone: data['contact']['phone'] as String,
      agentName: data['agentName'] as String,
      companyName: data['company']['name'] as String,
      companyLogo: data['company']['logo']['url'] as String,
      furnished: data['furnished'] as String,
      virtualTours: data['virtualTours'] as int,
      imageCount: data['imageCount'] as int,
      videos: data['videos'] as int,
      cost: data['cost'] as int,
      details: data['details'] as String,
    );
  }
}

Widget implementation:

import 'package:flutter/material.dart';
import 'package:my_app/models/listing.dart';
import 'package:my_app/data_service.dart';

class ListingScreen extends StatefulWidget {
  const ListingScreen({Key? key}) : super(key: key);

  @override
  State<ListingScreen> createState() => _ListingScreenState();
}

class _ListingScreenState extends State<ListingScreen> {
  List<Listing>? _listings;
  bool _dataLoaded = false;
  
  @override
  void initState() {
    super.initState();
    loadData();
  }

  Future<void> loadData() async {
    _listings = await DataService().fetchListings();
    if (_listings != null) {
      setState(() {
        _dataLoaded = true;
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Visibility(
        visible: _dataLoaded,
        child: ListView.builder(
          itemCount: _listings?.length,
          itemBuilder: (context, index) {
            return Container(
              child: Text("Data loaded"),
            );
          }
        ),
        replacement: Center(
          child: CircularProgressIndicator(),
        ),
      )
    );
  }
}

Any ideas what might be causing this connection issue?

[Ethan_19Chess]

Your code has a basic mismatch - your API returns raw JSON but your widget expects a List<Listing>. You’re not actually converting the JSON into Listing objects. Replace your return statement with: dart var data = json.decode(result.body); return (data['results'] as List).map((item) => Listing.fromJson(item)).toList(); The key might be different depending on RapidAPI’s structure. I’ve seen responses wrap the array in ‘data’, ‘results’, or ‘listings’. Add print(result.body) or use a REST client to check the actual response structure first.

[SilentSailing34]

Had this exact problem last month with a different RapidAPI endpoint. Your code looks fine, but there’s a critical issue with error handling. When the API call fails, you’re throwing an exception but your widget isn’t catching it. So setState never runs and the loading indicator spins forever. Wrap your DataService call in try-catch and update your _dataLoaded flag even when requests fail. Also double-check you’re using the right HTTP method - some RapidAPI endpoints need POST instead of GET even for retrieving data. I wasted hours debugging before realizing their docs lied about the required method.

[Mike71]

wrap your entire loadData method in a try-catch block. the api’s probably throwing an exception but flutter fails silently so you never see it. add debug prints like print(‘starting api call’) and print(‘got response: ${result.statusCode}’) to see where it’s breaking. also, rapidapi sometimes needs the content-type header set to application/json.

[rustyGuitar9]

The Problem:

You’re experiencing issues fetching data from a RapidAPI service in your Flutter app. The loading indicator remains active indefinitely, indicating a problem with your HTTP request. You’ve verified your headers and endpoint URL, but the issue persists. The core problem lies in how you’re handling the API response and potential errors. Directly working with RapidAPI introduces complexities like inconsistent response formats and potential rate limiting.

Understanding the “Why” (The Root Cause):

Directly integrating with third-party APIs like RapidAPI in your Flutter app can be challenging. These APIs often have:

• Inconsistent response structures: The format of the JSON data returned might not perfectly match your expectations. This requires careful parsing and handling of potential variations in the data structure.
• Error handling complexities: API calls can fail for various reasons (network issues, rate limiting, authentication errors). Without proper error handling, your app might hang or crash silently.
• Maintenance overhead: Changes in the API’s response format or structure may require updates to your Flutter code.

The suggested solution proposes creating an API proxy to act as an intermediary between your Flutter app and RapidAPI. This approach simplifies integration by:

• Standardizing the response: Your proxy can parse the potentially inconsistent RapidAPI response and transform it into a consistent format suitable for your Flutter app.
• Centralizing error handling and retry logic: The proxy can handle network errors, rate limiting, and authentication issues, ensuring your Flutter app receives reliable data.
• Improving maintainability: Changes in the RapidAPI structure are contained within the proxy, reducing the impact on your Flutter code.

Step-by-Step Guide:

1. Create an API Proxy: Build a simple API (using Node.js, Python, etc.) that acts as a proxy. This proxy will handle the communication with RapidAPI. This involves making the request to RapidAPI using tools like axios (Node.js) or the requests library (Python). This proxy will receive the response from RapidAPI, parse it, and convert it into a consistent, simplified JSON structure before sending it to your Flutter app.

2. Implement Data Transformation: In your proxy, parse the JSON response from RapidAPI. Extract only the necessary data and restructure it into a predictable format before sending it to your Flutter app. This might involve using JSON manipulation libraries or custom parsing logic.

3. Handle Errors Gracefully: Add robust error handling to your proxy to manage potential issues (network errors, HTTP error codes, etc.). The proxy should return a standardized error response to your Flutter app, allowing for consistent error handling in your application.

4. Update Your Flutter App: Modify your Flutter DataService class to point to your newly created API proxy endpoint instead of the RapidAPI endpoint directly. Your fetchListings() method will now be simpler, as the data will already be in the expected format. Also, adjust error handling to handle the specific error responses from your proxy.

5. Deploy Your Proxy: Deploy your API proxy to a server (e.g., Heroku, AWS, Netlify). This will make your proxy accessible to your Flutter app.

Common Pitfalls & What to Check Next:

• Incorrect API Key: Double-check that your API key is correct and has the necessary permissions to access the required RapidAPI endpoint.
• Rate Limiting: If you’re making frequent requests, you might be hitting RapidAPI’s rate limits. Monitor your requests and consider implementing rate limiting in your proxy to avoid exceeding the limits.
• Network Connectivity: Ensure your proxy and Flutter app have reliable internet connectivity.
• CORS Issues: If your proxy and Flutter app are deployed separately, ensure that your proxy is configured to handle Cross-Origin Resource Sharing (CORS) requests.

Still running into issues? Share your (sanitized) config files, the exact command you ran, and any other relevant details. The community is here to help!

[DancingButterfly]

The issue seems to lie in your fetchListings() method. You’re currently returning json.decode(result.body) without converting it to List<Listing>?, which can lead to unexpected results. RapidAPI responses often encapsulate returned data within a parent object; for instance, try accessing json.decode(result.body)['properties'] to get the actual list, depending on the response structure. Additionally, ‘useQueryString’ is not a header; it should be part of your request configuration. Adding debug prints to display the response structure may assist you in resolving this issue.

[Mandy_45Photography]

check your api key permissions first - i had the same issue with rapidapi where my subscription didn’t cover that endpoint. also print result.statuscode and result.body to see what you’re actually getting back. you might be getting a 401 or 403 instead of 200.