Flutter Firebase Image & File Upload CRUD

Previously we did Flutter Firebase CRUD for text information. Flutter firebase image and file upload we will use three plugins. 

firebase_storage: 
image_picker: 
path: 

First create a project and then install the above three plugins.

Android settings

Android doesn't need much settings. Just in AndroidManifest.xml file do the follow

 android:requestLegacyExternalStorage=”true”

iOS settings

iOS setting is also relatively easy. Just put the code in the Info.plist right after first <dict>

<key>NSCameraUsageDescription</key>
<string>Some Description</string>
<key>NSMicrophoneUsageDescription</key>
<string>Some Description</string>
<key>NSPhotoLibraryUsageDescription</key>
<string>Some Description</string>

Warnings: iOS simulator on Mac M1 chip doesn't support a stable image_picker plugin.

Core functions

≥ await picker.pickImage()

≥ await storage.ref(fileName).putFile()

Complete code

// main.dart
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'dart:io';
import 'package:firebase_core/firebase_core.dart';
import 'package:firebase_storage/firebase_storage.dart';
import 'package:path/path.dart' as path;
import 'package:image_picker/image_picker.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();

  // Initialize a new Firebase App instance
  await Firebase.initializeApp();
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      // Remove the debug banner
      debugShowCheckedModeBanner: false,
      title: 'dbestech',
      theme: ThemeData(primarySwatch: Colors.green),
      home: const HomePage(),
    );
  }
}

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

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

class _HomePageState extends State<HomePage> {
  FirebaseStorage storage = FirebaseStorage.instance;

  // Select and image from the gallery or take a picture with the camera
  // Then upload to Firebase Storage
  Future<void> _upload(String inputSource) async {
    final picker = ImagePicker();
    XFile? pickedImage;
    try {
      pickedImage = await picker.pickImage(
          source: inputSource == 'camera'
              ? ImageSource.camera
              : ImageSource.gallery,
          maxWidth: 1920);

      final String fileName = path.basename(pickedImage!.path);
      File imageFile = File(pickedImage.path);

      try {
        // Uploading the selected image with some custom meta data
        await storage.ref(fileName).putFile(
            imageFile,
            SettableMetadata(customMetadata: {
              'uploaded_by': 'learners',
              'description': 'learning the hacks'
            }));

        // Refresh the UI
        setState(() {});
      } on FirebaseException catch (error) {
        if (kDebugMode) {
          print(error);
        }
      }
    } catch (err) {
      if (kDebugMode) {
        print(err);
      }
    }
  }

  // Retriew the uploaded images
  // This function is called when the app launches for the first time or when an image is uploaded or deleted
  Future<List<Map<String, dynamic>>> _loadImages() async {
    List<Map<String, dynamic>> files = [];

    final ListResult result = await storage.ref().list();
    final List<Reference> allFiles = result.items;

    await Future.forEach<Reference>(allFiles, (file) async {
      final String fileUrl = await file.getDownloadURL();
      final FullMetadata fileMeta = await file.getMetadata();
      files.add({
        "url": fileUrl,
        "path": file.fullPath,
        "uploaded_by": fileMeta.customMetadata?['uploaded_by'] ?? 'Nobody',
        "description":
            fileMeta.customMetadata?['description'] ?? 'No description'
      });
    });

    return files;
  }

  // Delete the selected image
  // This function is called when a trash icon is pressed
  Future<void> _delete(String ref) async {
    await storage.ref(ref).delete();
    // Rebuild the UI
    setState(() {});
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('dbestech),
      ),
      body: Padding(
        padding: const EdgeInsets.all(20),
        child: Column(
          children: [
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceAround,
              children: [
                ElevatedButton.icon(
                    onPressed: () => _upload('camera'),
                    icon: const Icon(Icons.camera),
                    label: const Text('camera')),
                ElevatedButton.icon(
                    onPressed: () => _upload('gallery'),
                    icon: const Icon(Icons.library_add),
                    label: const Text('Gallery')),
              ],
            ),
            Expanded(
              child: FutureBuilder(
                future: _loadImages(),
                builder: (context,
                    AsyncSnapshot<List<Map<String, dynamic>>> snapshot) {
                  if (snapshot.connectionState == ConnectionState.done) {
                    return ListView.builder(
                      itemCount: snapshot.data?.length ?? 0,
                      itemBuilder: (context, index) {
                        final Map<String, dynamic> image =
                            snapshot.data![index];

                        return Card(
                          margin: const EdgeInsets.symmetric(vertical: 10),
                          child: ListTile(
                            dense: false,
                            leading: Image.network(image['url']),
                            title: Text(image['uploaded_by']),
                            subtitle: Text(image['description']),
                            trailing: IconButton(
                              onPressed: () => _delete(image['path']),
                              icon: const Icon(
                                Icons.delete,
                                color: Colors.red,
                              ),
                            ),
                          ),
                        );
                      },
                    );
                  }

                  return const Center(
                    child: CircularProgressIndicator(),
                  );
                },
              ),
            ),
          ],
        ),
      ),
    );
  }
}

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