Why do I get an Invalid argument error in my Flutter API test?

Question

I'm trying to display a photo (for now), gotten from a Flickr API, and I'm facing issues. When I run my code, I get an E/ion (11941): ioctl c0044901 failed with code -1: Invalid argument error. I had to deal with a lot of typing issues to get to this point and I'm guessing it's typing errors all the way down, but I can't figure out where.

import 'dart:async';
import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;

Future<List<Photo>> fetchPhoto() async {
  final response = await http
      .get(Uri.parse('https://www.flickr.com/services/rest/?method=flickr.photos.search&api_key=d92076c10463fe13f610511210b3dee9&user_id=&tags=tattoo&privacy_filter=1&safe_search=1&content_type=1&format=json&nojsoncallback=1'));

  if (response.statusCode == 200) {
    return jsonDecode(response.body)['photos']['photo'].map<Photo>((element) => Photo.fromJson(element)).toList();
  } else {
    throw Exception('Failed to load photo');
  }
}

class Photo {
  final String owner;
  final String id;
  final String title;

  const Photo({
    required this.owner,
    required this.id,
    required this.title,
  });

  factory Photo.fromJson(Map<String, dynamic> json) {
    return Photo(
      owner: json.values.toList()[1],
      id: json.values.toList()[0],
      title: json.values.toList()[5],
    );
  }
}

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

  @override
  _HomescreenState createState() => _HomescreenState();
}

class _HomescreenState extends State<Homescreen> {
  late Future<List<Photo>> futurePhoto = fetchPhoto();

  @override
  void initState() {
    futurePhoto = fetchPhoto();
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        Center(
          child: FutureBuilder<List<Photo>>(
            future: futurePhoto,
            builder: (context, snapshot) {
              if (snapshot.hasData) {
                  Container(
                  decoration: BoxDecoration(border: Border.all(color: Colors.black)),
                  margin: const EdgeInsets.all(10),
                  padding: const EdgeInsets.all(10),
                  child: Column(
                      children: [
                        Image.network('https://www.flickr.com/photos/' + snapshot.data![0].owner + '/' + snapshot.data![0].id)
                      ]
                  )
                );
              } else if (snapshot.hasError) {
                return Text('${snapshot.error}');
              }
            return const CircularProgressIndicator();
            },
          ),
        ),
      ],
    );
  }
}

Also I'm guessing I'm not treating my API request in the best way available, so if someone could give me pointers on how to not make it such a mess, it'd be much appreciated.

Answer 1

Turns out, it was only the debugger sending the invalid argument error, and the reason the code didn't work was that I was constructing the image URL in the wrong way.