I have the following problem: right now there is an app in the PlayStore that is written in native code (both iOS and Android) which I'm planning on migrating to flutter. My aim is that the users don't notice there were changes under the hood but can continue using the app like before. For that I need to migrate the shared preferences as well. This is, however, quite difficult. In the native Android application I stored the relevant shared preference like this:
SharedPreferences sharedPrefs = context.getSharedPreferences(
"storage",
Context.MODE_PRIVATE
);
sharedPrefs.putString('guuid', 'guuid_value');
editor.apply();
which results in a file being created at this path:
/data/data/patavinus.patavinus/shared_prefs/storage.xml
with this content:
<?xml version='1.0' encoding='utf-8' standalone='yes' ?>
<map>
<int name="guuid" value="guuid_value" />
</map>
If I use shared_prefences in Flutter to obtain this value by doing this:
final sharedPreferences = await SharedPreferences.getInstance();
sharedPreferences.getString('guuid');
it returns null because it looks for
/data/data/patavinus.patavinus/shared_prefs/FlutterSharedPreferences.xml which is the file that is written to when using shared_preferences in Flutter to store shared preferences. Because the shared prefs were written in native app context, the file is obviously not there.
Is there any way to tell Flutter to look for /data/data/patavinus.patavinus/shared_prefs/storage.xml without having to use platform channel?
I know how this works the other way around like it's mentioned here: How to access flutter Shared preferences on the android end (using java). This way is easy because in Android you can choose to prepend Flutter's prefix. However, in Flutter you can't.
I am also aware of this plugin: https://pub.dev/packages/native_shared_preferences however, I can't believe that a third party plugin is the recommended way. Also, I have spread the relevant shared preferences across multiple resource files. In this plugin, you can only set one (by specifying the string resource flutter_shared_pref_name).
As suggested here you can get the native file's content and copy it to a new file. You can copy the content to flutter's storage file when the user upgrades to your flutter app for the first time.
Best option is to store shared preferences in native part in same file as SharedPreferences plugin does it. So it means to do like that:
In Java code replace your SharedPreferences code, with same key, as it is in plugin: SharedPreferences sharedPref = context.getSharedPreferences("FlutterSharedPreferences", Context.MODE_PRIVATE);
In native part save all preferences with prefix "flutter.". So in native part you will get needed preferences like this: String test = sharedPref.getString("flutter.test", "");
Since there was no satisfying answer to my question that works for both of the major operating systems and taking into account the distribution over multiple resource files, I have written a platform channel solution myself.
On Android (Kotlin) I let the caller provide a "file" argument because it's possible to have the data spread over multiple resource files (like I described in my question).
package my.test
import android.content.*
import androidx.annotation.NonNull
import io.flutter.embedding.android.FlutterActivity
import io.flutter.embedding.engine.FlutterEngine
import io.flutter.plugin.common.MethodChannel
class MainActivity: FlutterActivity() {
private val CHANNEL = "testChannel"
override fun configureFlutterEngine(#NonNull flutterEngine: FlutterEngine) {
super.configureFlutterEngine(flutterEngine)
MethodChannel(flutterEngine.dartExecutor.binaryMessenger, CHANNEL).setMethodCallHandler {
call, result ->
when (call.method) {
"getStringValue" -> {
val key: String? = call.argument<String>("key");
val file: String? = call.argument<String>("file");
when {
key == null -> {
result.error("KEY_MISSING", "Argument 'key' is not provided.", null)
}
file == null -> {
result.error("FILE_MISSING", "Argument 'file' is not provided.", null)
}
else -> {
val value: String? = getStringValue(file, key)
result.success(value)
}
}
}
else -> {
result.notImplemented()
}
}
}
}
private fun getStringValue(file: String, key: String): String? {
return context.getSharedPreferences(
file,
Context.MODE_PRIVATE
).getString(key, null);
}
}
On iOS (Swift) this is not necessary as I'm working with UserDefaults
#UIApplicationMain
#objc class AppDelegate: FlutterAppDelegate {
override func application(
_ application: UIApplication,
didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
) -> Bool {
let controller : FlutterViewController = window?.rootViewController as! FlutterViewController
let platformChannel = FlutterMethodChannel(
name: "testChannel",
binaryMessenger: controller.binaryMessenger
)
platformChannel.setMethodCallHandler({
[weak self] (call: FlutterMethodCall, result: FlutterResult) -> Void in
guard call.method == "getStringValue" else {
result(FlutterMethodNotImplemented)
return
}
if let args: Dictionary<String, Any> = call.arguments as? Dictionary<String, Any>,
let number: String = args["key"] as? String, {
self?.getStringValue(key: key, result: result)
return
} else {
result(
FlutterError.init(
code: "KEY_MISSING",
message: "Argument 'key' is not provided.",
details: nil
)
)
}
})
GeneratedPluginRegistrant.register(with: self)
return super.application(application, didFinishLaunchingWithOptions: launchOptions)
}
}
private func getStringValue(key: String, result: FlutterResult) -> String? {
let fetchedValue: String? = UserDefaults.object(forKey: key) as? String
result(fetchedValue)
}
I'd wish for the SharedPreferences package to add the possibility of omitting the flutter prefix, enabling the developer to migrate content seamlessly from native apps.
I also wrote a blog post that explains the problem and the solution in a little bit more details: https://www.flutterclutter.dev/flutter/tutorials/read-shared-preferences-from-native-apps/2021/9753/
I am also aware of this plugin: https://pub.dev/packages/native_shared_preferences however, I can't believe that a third party plugin is the recommended way.
I think the third party plugin is just fine. The best thing about flutter is its amazing community that keeps contributing thoroughly to the ecosystem. That said, I would not recommend keeping using the non-official library. So you could test migrating your shared preferences behind the scenes.
In your initState query for flutter shared preferences.
If they exist, skip.
If they don't exist, query for native shared preferences, copy if exist
And done. This will help with the migration IMHO.
My choice is to treat it just as a file.
In flutter read the android shared preference file
/data/data/patavinus.patavinus/shared_prefs/storage.xml
take the values in the way you handle other xml file.
If you want to make some changes, don't use sharedPrefs.put, Instead write into the file (/data/data/patavinus.patavinus/shared_prefs/storage.xml
) using file's write method in flutter
I'm working on uploading images, everything works great, but I have 100 pictures and I would like to show all of them in my View, as I get the complete list of the images in a folder, I can not find any API for this work.
Since Firebase SDKs for JavaScript release 6.1, iOS release 6.4, and Android release version 18.1 all have a method to list files.
The documentation is a bit sparse so far, so I recommend checking out Rosário's answer for details.
Previous answer, since this approach can still be useful at times:
There currently is no API call in the Firebase SDK to list all files in a Cloud Storage folder from within an app. If you need such functionality, you should store the metadata of the files (such as the download URLs) in a place where you can list them. The Firebase Realtime Database and Cloud Firestore are perfect for this and allows you to also easily share the URLs with others.
You can find a good (but somewhat involved) sample of this in our FriendlyPix sample app. The relevant code for the web version is here, but there are also versions for iOS and Android.
As of May 2019, version 6.1.0 of the Firebase SDK for Cloud Storage now supports listing all objects from a bucket. You simply need to call listAll() in a Reference:
// Since you mentioned your images are in a folder,
// we'll create a Reference to that folder:
var storageRef = firebase.storage().ref("your_folder");
// Now we get the references of these images
storageRef.listAll().then(function(result) {
result.items.forEach(function(imageRef) {
// And finally display them
displayImage(imageRef);
});
}).catch(function(error) {
// Handle any errors
});
function displayImage(imageRef) {
imageRef.getDownloadURL().then(function(url) {
// TODO: Display the image on the UI
}).catch(function(error) {
// Handle any errors
});
}
Please note that in order to use this function, you must opt-in to version 2 of Security Rules, which can be done by making rules_version = '2'; the first line of your security rules:
rules_version = '2';
service firebase.storage {
match /b/{bucket}/o {
match /{allPaths=**} {
I'd recommend checking the docs for further reference.
Also, according to setup, on Step 5, this script is not allowed for Node.js since require("firebase/app"); won't return firebase.storage() as a function. This is only achieved using import * as firebase from 'firebase/app';.
Since Mar 2017: With the addition of Firebase Cloud Functions, and Firebase's deeper integration with Google Cloud, this is now possible.
With Cloud Functions you can use the Google Cloud Node package to do epic operations on Cloud Storage. Below is an example that gets all the file URLs into an array from Cloud Storage. This function will be triggered every time something's saved to google cloud storage.
Note 1: This is a rather computationally expensive operation, as it has to cycle through all files in a bucket / folder.
Note 2: I wrote this just as an example, without paying much detail into promises etc. Just to give an idea.
const functions = require('firebase-functions');
const gcs = require('#google-cloud/storage')();
// let's trigger this function with a file upload to google cloud storage
exports.fileUploaded = functions.storage.object().onChange(event => {
const object = event.data; // the object that was just uploaded
const bucket = gcs.bucket(object.bucket);
const signedUrlConfig = { action: 'read', expires: '03-17-2025' }; // this is a signed url configuration object
var fileURLs = []; // array to hold all file urls
// this is just for the sake of this example. Ideally you should get the path from the object that is uploaded :)
const folderPath = "a/path/you/want/its/folder/size/calculated";
bucket.getFiles({ prefix: folderPath }, function(err, files) {
// files = array of file objects
// not the contents of these files, we're not downloading the files.
files.forEach(function(file) {
file.getSignedUrl(signedUrlConfig, function(err, fileURL) {
console.log(fileURL);
fileURLs.push(fileURL);
});
});
});
});
I hope this will give you the general idea. For better cloud functions examples, check out Google's Github repo full of Cloud Functions samples for Firebase. Also check out their Google Cloud Node API Documentation
Since there's no language listed, I'll answer this in Swift. We highly recommend using Firebase Storage and the Firebase Realtime Database together to accomplish lists of downloads:
Shared:
// Firebase services
var database: FIRDatabase!
var storage: FIRStorage!
...
// Initialize Database, Auth, Storage
database = FIRDatabase.database()
storage = FIRStorage.storage()
...
// Initialize an array for your pictures
var picArray: [UIImage]()
Upload:
let fileData = NSData() // get data...
let storageRef = storage.reference().child("myFiles/myFile")
storageRef.putData(fileData).observeStatus(.Success) { (snapshot) in
// When the image has successfully uploaded, we get it's download URL
let downloadURL = snapshot.metadata?.downloadURL()?.absoluteString
// Write the download URL to the Realtime Database
let dbRef = database.reference().child("myFiles/myFile")
dbRef.setValue(downloadURL)
}
Download:
let dbRef = database.reference().child("myFiles")
dbRef.observeEventType(.ChildAdded, withBlock: { (snapshot) in
// Get download URL from snapshot
let downloadURL = snapshot.value() as! String
// Create a storage reference from the URL
let storageRef = storage.referenceFromURL(downloadURL)
// Download the data, assuming a max size of 1MB (you can change this as necessary)
storageRef.dataWithMaxSize(1 * 1024 * 1024) { (data, error) -> Void in
// Create a UIImage, add it to the array
let pic = UIImage(data: data)
picArray.append(pic)
})
})
For more information, see Zero to App: Develop with Firebase, and it's associated source code, for a practical example of how to do this.
I also encountered this problem when I was working on my project. I really wish they provide an end api method. Anyway, This is how I did it:
When you are uploading an image to Firebase storage, create an Object and pass this object to Firebase database at the same time. This object contains the download URI of the image.
trailsRef.putFile(file).addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
#Override
public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
Uri downloadUri = taskSnapshot.getDownloadUrl();
DatabaseReference myRef = database.getReference().child("trails").child(trail.getUnique_id()).push();
Image img = new Image(trail.getUnique_id(), downloadUri.toString());
myRef.setValue(img);
}
});
Later when you want to download images from a folder, you simply iterate through files under that folder. This folder has the same name as the "folder" in Firebase storage, but you can name them however you want to. I put them in separate thread.
#Override
protected List<Image> doInBackground(Trail... params) {
String trialId = params[0].getUnique_id();
mDatabase = FirebaseDatabase.getInstance().getReference();
mDatabase.child("trails").child(trialId).addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
images = new ArrayList<>();
Iterator<DataSnapshot> iter = dataSnapshot.getChildren().iterator();
while (iter.hasNext()) {
Image img = iter.next().getValue(Image.class);
images.add(img);
}
isFinished = true;
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
Now I have a list of objects containing the URIs to each image, I can do whatever I want to do with them. To load them into imageView, I created another thread.
#Override
protected List<Bitmap> doInBackground(List<Image>... params) {
List<Bitmap> bitmaps = new ArrayList<>();
for (int i = 0; i < params[0].size(); i++) {
try {
URL url = new URL(params[0].get(i).getImgUrl());
Bitmap bmp = BitmapFactory.decodeStream(url.openConnection().getInputStream());
bitmaps.add(bmp);
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
return bitmaps;
}
This returns a list of Bitmap, when it finishes I simply attach them to ImageView in the main activity. Below methods are #Override because I have interfaces created and listen for completion in other threads.
#Override
public void processFinishForBitmap(List<Bitmap> bitmaps) {
List<ImageView> imageViews = new ArrayList<>();
View v;
for (int i = 0; i < bitmaps.size(); i++) {
v = mInflater.inflate(R.layout.gallery_item, mGallery, false);
imageViews.add((ImageView) v.findViewById(R.id.id_index_gallery_item_image));
imageViews.get(i).setImageBitmap(bitmaps.get(i));
mGallery.addView(v);
}
}
Note that I have to wait for List Image to be returned first and then call thread to work on List Bitmap. In this case, Image contains the URI.
#Override
public void processFinish(List<Image> results) {
Log.e(TAG, "get back " + results.size());
LoadImageFromUrlTask loadImageFromUrlTask = new LoadImageFromUrlTask();
loadImageFromUrlTask.delegate = this;
loadImageFromUrlTask.execute(results);
}
Hopefully someone finds it helpful. It will also serve as a guild line for myself in the future too.
Combining some answers from this post and also from here, and after some personal research, for NodeJS with typescript I managed to accomplish this by using firebase-admin:
import * as admin from 'firebase-admin';
const getFileNames = () => {
admin.storage().bucket().getFiles(autoPaginate: false).then(([files]: any) => {
const fileNames = files.map((file: any) => file.name);
return fileNames;
})
}
In my case I also needed to get all the files inside a specific folder from firebase storage. According to google storage the folders don't exists but are rather a naming conventions. Anyway I managed to to this (without saving each file full path into DB) by adding { prefix: ${folderName}, autoPaginate: false } inside the getFiles function call so:
...
const getFileNames = (folderName: string) => {
admin.storage().bucket().getFiles({ prefix: `${folderName}`, autoPaginate: false })
.then(([files]: any) => {
...
You can list files in a directory of firebase storage by listAll() method.
To use this method, have to implement this version of firebase storage.
'com.google.firebase:firebase-storage:18.1.1'
https://firebase.google.com/docs/storage/android/list-files
Keep in mind that upgrade the Security Rules to version 2.
A workaround can be to create a file (i.e list.txt) with nothing inside, in this file you can set the custom metadata (that is a Map< String, String>) with the list of all the file's URL.So if you need to downlaod all the files in a fodler you first download the metadata of the list.txt file, then you iterate through the custom data and download all the files with the URLs in the Map.
One more way to add the image to Database using Cloud Function to track every uploaded image and store it in Database.
exports.fileUploaded = functions.storage.object().onChange(event => {
const object = event.data; // the object that was just uploaded
const contentType = event.data.contentType; // This is the image Mimme type\
// Exit if this is triggered on a file that is not an image.
if (!contentType.startsWith('image/')) {
console.log('This is not an image.');
return null;
}
// Get the Signed URLs for the thumbnail and original image.
const config = {
action: 'read',
expires: '03-01-2500'
};
const bucket = gcs.bucket(event.data.bucket);
const filePath = event.data.name;
const file = bucket.file(filePath);
file.getSignedUrl(config, function(err, fileURL) {
console.log(fileURL);
admin.database().ref('images').push({
src: fileURL
});
});
});
Full code here:
https://gist.github.com/bossly/fb03686f2cb1699c2717a0359880cf84
For node js, I used this code
const Storage = require('#google-cloud/storage');
const storage = new Storage({projectId: 'PROJECT_ID', keyFilename: 'D:\\keyFileName.json'});
const bucket = storage.bucket('project.appspot.com'); //gs://project.appspot.com
bucket.getFiles().then(results => {
const files = results[0];
console.log('Total files:', files.length);
files.forEach(file => {
file.download({destination: `D:\\${file}`}).catch(error => console.log('Error: ', error))
});
}).catch(err => {
console.error('ERROR:', err);
});
Actually this is possible but only with a Google Cloud API instead one from Firebase. It's because a Firebase Storage is a Google Cloud Storage Bucket which can be reached easily with the Google Cloud APIs however you need to use OAuth for Authentication instead of the Firebase one's.
#In Python
import firebase_admin
from firebase_admin import credentials
from firebase_admin import storage
import datetime
import urllib.request
def image_download(url, name_img) :
urllib.request.urlretrieve(url, name_img)
cred = credentials.Certificate("credentials.json")
# Initialize the app with a service account, granting admin privileges
app = firebase_admin.initialize_app(cred, {
'storageBucket': 'YOURSTORAGEBUCKETNAME.appspot.com',
})
url_img = "gs://YOURSTORAGEBUCKETNAME.appspot.com/"
bucket_1 = storage.bucket(app=app)
image_urls = []
for blob in bucket_1.list_blobs():
name = str(blob.name)
#print(name)
blob_img = bucket_1.blob(name)
X_url = blob_img.generate_signed_url(datetime.timedelta(seconds = 300), method='GET')
#print(X_url)
image_urls.append(X_url)
PATH = ['Where you want to save the image']
for path in PATH:
i = 1
for url in image_urls:
name_img = str(path + "image"+str(i)+".jpg")
image_download(url, name_img)
i+=1
Extending Rosário Pereira Fernandes' answer, for a JavaScript solution:
Install firebase on your machine
npm install -g firebase-tools
On firebase init set JavaScript as default language
On the root folder of created project execute npm installs
npm install --save firebase
npm install #google-cloud/storage
npm install #google-cloud/firestore
... <any other dependency needed>
Add non-default dependencies on your project like
"firebase": "^6.3.3",
"#google-cloud/storage": "^3.0.3"
functions/package.json
{
"name": "functions",
"description": "Cloud Functions for Firebase",
"scripts": {
"lint": "eslint .",
"serve": "firebase serve --only functions",
"shell": "firebase functions:shell",
"start": "npm run shell",
"deploy": "firebase deploy --only functions",
"logs": "firebase functions:log"
},
"engines": {
"node": "10"
},
"dependencies": {
"#google-cloud/storage": "^3.0.3",
"firebase": "^6.3.3",
"firebase-admin": "^8.0.0",
"firebase-functions": "^3.1.0"
},
"devDependencies": {
"eslint": "^5.12.0",
"eslint-plugin-promise": "^4.0.1",
"firebase-functions-test": "^0.1.6"
},
"private": true
}
Create sort of a listAll function
index.js
var serviceAccount = require("./key.json");
const functions = require('firebase-functions');
const images = require('./images.js');
var admin = require("firebase-admin");
admin.initializeApp({
credential: admin.credential.cert(serviceAccount),
databaseURL: "https://<my_project>.firebaseio.com"
});
const bucket = admin.storage().bucket('<my_bucket>.appspot.com')
exports.getImages = functions.https.onRequest((request, response) => {
images.getImages(bucket)
.then(urls => response.status(200).send({ data: { urls } }))
.catch(err => console.error(err));
})
images.js
module.exports = {
getImages
}
const query = {
directory: 'images'
};
function getImages(bucket) {
return bucket.getFiles(query)
.then(response => getUrls(response))
.catch(err => console.error(err));
}
function getUrls(response) {
const promises = []
response.forEach( files => {
files.forEach (file => {
promises.push(getSignedUrl(file));
});
});
return Promise.all(promises).then(result => getParsedUrls(result));
}
function getSignedUrl(file) {
return file.getSignedUrl({
action: 'read',
expires: '09-01-2019'
})
}
function getParsedUrls(result) {
return JSON.stringify(result.map(mediaLink => createMedia(mediaLink)));
}
function createMedia(mediaLink) {
const reference = {};
reference.mediaLink = mediaLink[0];
return reference;
}
Execute firebase deploy to upload your cloud function
Call your custom function from your app
build.gradle
dependencies {
...
implementation 'com.google.firebase:firebase-functions:18.1.0'
...
}
kotlin class
private val functions = FirebaseFunctions.getInstance()
val cloudFunction = functions.getHttpsCallable("getImages")
cloudFunction.call().addOnSuccessListener {...}
Regarding the further development of this feature, I ran into some problems that might found here.
I am using AngularFire and use the following for get all of the downloadURL
getPhotos(id: string): Observable<string[]> {
const ref = this.storage.ref(`photos/${id}`)
return ref.listAll().pipe(switchMap(list => {
const calls: Promise<string>[] = [];
list.items.forEach(item => calls.push(item.getDownloadURL()))
return Promise.all(calls)
}));
}
I faced the same issue, mine is even more complicated.
Admin will upload audio and pdf files into storage:
audios/season1, season2.../class1, class 2/.mp3 files
books/.pdf files
Android app needs to get the list of sub folders and files.
The solution is catching the upload event on storage and create the same structure on firestore using cloud function.
Step 1: Create manually 'storage' collection and 'audios/books' doc on firestore
Step 2: Setup cloud function
Might take around 15 mins: https://www.youtube.com/watch?v=DYfP-UIKxH0&list=PLl-K7zZEsYLkPZHe41m4jfAxUi0JjLgSM&index=1
Step 3: Catch upload event using cloud function
import * as functions from 'firebase-functions';
import * as admin from 'firebase-admin';
admin.initializeApp(functions.config().firebase);
const path = require('path');
export const onFileUpload = functions.storage.object().onFinalize(async (object) => {
let filePath = object.name; // File path in the bucket.
const contentType = object.contentType; // File content type.
const metageneration = object.metageneration; // Number of times metadata has been generated. New objects have a value of 1.
if (metageneration !== "1") return;
// Get the file name.
const fileName = path.basename(filePath);
filePath = filePath.substring(0, filePath.length - 1);
console.log('contentType ' + contentType);
console.log('fileName ' + fileName);
console.log('filePath ' + filePath);
console.log('path.dirname(filePath) ' + path.dirname(filePath));
filePath = path.dirname(filePath);
const pathArray = filePath.split("/");
let ref = '';
for (const item of pathArray) {
if (ref.length === 0) {
ref = item;
}
else {
ref = ref.concat('/sub/').concat(item);
}
}
ref = 'storage/'.concat(ref).concat('/sub')
admin.firestore().collection(ref).doc(fileName).create({})
.then(result => {console.log('onFileUpload:updated')})
.catch(error => {
console.log(error);
});
});
Step 4: Retrieve list of folders/files on Android app using firestore
private static final String STORAGE_DOC = "storage/";
public static void getMediaCollection(String path, OnCompleteListener onCompleteListener) {
String[] pathArray = path.split("/");
String doc = null;
for (String item : pathArray) {
if (TextUtils.isEmpty(doc)) doc = STORAGE_DOC.concat(item);
else doc = doc.concat("/sub/").concat(item);
}
doc = doc.concat("/sub");
getFirestore().collection(doc).get().addOnCompleteListener(onCompleteListener);
}
Step 5: Get download url
public static void downloadMediaFile(String path, OnCompleteListener<Uri> onCompleteListener) {
getStorage().getReference().child(path).getDownloadUrl().addOnCompleteListener(onCompleteListener);
}
Note
We have to put "sub" collection to each item since firestore doesn't support to retrieve the list of collection.
It took me 3 days to find out the solution, hopefully will take you 3 hours at most.
To do this with JS
You can append them directly to your div container, or you can push them to an array. The below shows you how to append them to your div.
1) When you store your images in storage create a reference to the image in your firebase database with the following structure
/images/(imageName){
description: "" ,
imageSrc : (imageSource)
}
2) When you load you document pull all your image source URLs from the database rather than the storage with the following code
$(document).ready(function(){
var query = firebase.database().ref('images/').orderByKey();
query.once("value").then(function(snapshot){
snapshot.forEach(function(childSnapshot){
var imageName = childSnapshot.key;
var childData = childSnapshot.val();
var imageSource = childData.url;
$('#imageGallery').append("<div><img src='"+imageSource+"'/></div>");
})
})
});
You can use the following code. Here I am uploading the image to firebase storage and then I am storing the image download url to firebase database.
//getting the storage reference
StorageReference sRef = storageReference.child(Constants.STORAGE_PATH_UPLOADS + System.currentTimeMillis() + "." + getFileExtension(filePath));
//adding the file to reference
sRef.putFile(filePath)
.addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
#Override
public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
//dismissing the progress dialog
progressDialog.dismiss();
//displaying success toast
Toast.makeText(getApplicationContext(), "File Uploaded ", Toast.LENGTH_LONG).show();
//creating the upload object to store uploaded image details
Upload upload = new Upload(editTextName.getText().toString().trim(), taskSnapshot.getDownloadUrl().toString());
//adding an upload to firebase database
String uploadId = mDatabase.push().getKey();
mDatabase.child(uploadId).setValue(upload);
}
})
.addOnFailureListener(new OnFailureListener() {
#Override
public void onFailure(#NonNull Exception exception) {
progressDialog.dismiss();
Toast.makeText(getApplicationContext(), exception.getMessage(), Toast.LENGTH_LONG).show();
}
})
.addOnProgressListener(new OnProgressListener<UploadTask.TaskSnapshot>() {
#Override
public void onProgress(UploadTask.TaskSnapshot taskSnapshot) {
//displaying the upload progress
double progress = (100.0 * taskSnapshot.getBytesTransferred()) / taskSnapshot.getTotalByteCount();
progressDialog.setMessage("Uploaded " + ((int) progress) + "%...");
}
});
Now to fetch all the images stored in firebase database you can use
//adding an event listener to fetch values
mDatabase.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot snapshot) {
//dismissing the progress dialog
progressDialog.dismiss();
//iterating through all the values in database
for (DataSnapshot postSnapshot : snapshot.getChildren()) {
Upload upload = postSnapshot.getValue(Upload.class);
uploads.add(upload);
}
//creating adapter
adapter = new MyAdapter(getApplicationContext(), uploads);
//adding adapter to recyclerview
recyclerView.setAdapter(adapter);
}
#Override
public void onCancelled(DatabaseError databaseError) {
progressDialog.dismiss();
}
});
Fore more details you can see my post Firebase Storage Example.
In Swift
public func downloadData() async {
let imagesRef = storage.child("pictures/")
do {
let storageReference = try await storage.root().child("pictures").listAll()
print("storageReference: \(storageReference.items)")
} catch {
print(error)
}
}
Output
[
gs://<your_app_name>.appspot.com/pictures/IMG_1243.JPG,
gs://<your_app_name>.appspot.com/pictures/IMG_1244.JPG,
gs://<your_app_name>.appspot.com/pictures/IMG_1245.JPG,
gs://<your_app_name>.appspot.com/pictures/IMG_1246.JPG
]
Here is the reference
So I had a project that required downloading assets from firebase storage, so I had to solve this problem myself. Here is How :
1- First, make a model data for example class Choice{}, In that class defines a String variable called image Name so it will be like that
class Choice {
.....
String imageName;
}
2- from a database/firebase database, go and hardcode the image names to the objects, so if you have image name called Apple.png, create the object to be
Choice myChoice = new Choice(...,....,"Apple.png");
3- Now, get the link for the assets in your firebase storage which will be something like that
gs://your-project-name.appspot.com/
like this one
4- finally, initialize your firebase storage reference and start getting the files by a loop like that
storageRef = storage.getReferenceFromUrl(firebaseRefURL).child(imagePath);
File localFile = File.createTempFile("images", "png");
storageRef.getFile(localFile).addOnSuccessListener(new OnSuccessListener<FileDownloadTask.TaskSnapshot>() {
#Override
public void onSuccess(FileDownloadTask.TaskSnapshot taskSnapshot) {
//Dismiss Progress Dialog\\
}
5- that's it
For Android the best pratice is to use FirebaseUI and Glide.
You need to add that on your gradle/app in order to get the library. Note that it already has Glide on it!
implementation 'com.firebaseui:firebase-ui-storage:4.1.0'
And then in your code use
// Reference to an image file in Cloud Storage
StorageReference storageReference = FirebaseStorage.getInstance().getReference();
// ImageView in your Activity
ImageView imageView = findViewById(R.id.imageView);
// Download directly from StorageReference using Glide
// (See MyAppGlideModule for Loader registration)
GlideApp.with(this /* context */)
.load(storageReference)
.into(imageView);
I built an assembly containing one js file.
I marked the file as Embedded Resource and added it into AssemblyInfo file.
I can't refernce the Assembly from a web site. It is in the bin folder but I don't see the reference to it.
It seems like not having at least a class inside the assembly I can't reference it.
I would include the js file into my pages from the assembly.
How should I do this?
Thanks
I do exactly the same thing in one of my projects. I have a central ScriptManager class that actually caches the scripts as it pulls them, but the core of extracting the script file from the embedded resource looks like this:
internal static class ScriptManager
{
private static Dictionary<string, string> m_scriptCache =
new Dictionary<string, string>();
public static string GetScript(string scriptName)
{
return GetScript(scriptName, true);
}
public static string GetScript(string scriptName, bool encloseInCdata)
{
StringBuilder script = new StringBuilder("\r\n");
if (encloseInCdata)
{
script.Append("//<![CDATA[\r\n");
}
if (!m_scriptCache.ContainsKey(scriptName))
{
var asm = Assembly.GetExecutingAssembly();
var stream = asm.GetManifestResourceStream(scriptName);
if (stream == null)
{
var names = asm.GetManifestResourceNames();
// NOTE: you passed in an invalid name.
// Use the above line to determine what tyhe name should be
// most common is not setting the script file to be an embedded resource
if (Debugger.IsAttached) Debugger.Break();
return string.Empty;
}
using (var reader = new StreamReader(stream))
{
var text = reader.ReadToEnd();
m_scriptCache.Add(scriptName, text);
}
}
script.Append(m_scriptCache[scriptName]);
if (encloseInCdata)
{
script.Append("//]]>\r\n");
}
return script.ToString();
}
}
EDIT
To provide more clarity, I've posted my ScriptManager class. To extract a script file, I simply call it like this:
var script = ScriptManager.GetScript("Fully.Qualified.Script.js");
The name you pass in it the full, case-sensitive resource name (the exception handler gets a list of them by calling GetManifestResourceNames()).
This gives you the script as a string - you can then put it out into a file, inject it into the page (which is what I'm doing) or whatever you like.
Assembly myAssembly = // Get your assembly somehow (see below)...
IList<string> resourceNames = myAssembly.GetManifestResourceNames();
This will return a list of all resource names that have been set as 'Embedded Resource'. The name is usually the fully qualified namespace of wherever you put that JS file. So if your project is called My.Project and you store your MyScript.js file inside a folder in your project called Resources, the full name would be My.Project.Resources.MyScript.js
If you then want to use that JS file:
Stream stream = myAssembly.GetManifestResourceStream(myResourceName);
Where myResourceName argument might be "My.Project.Resources.MyScript.js". To get that JS file in that Stream object, you'll need to write it as a file to the hard drive, and serve it from your website as a static file, something like this:
Stream stream = executingAssembly.GetManifestResourceStream(imageResourcePath);
if (stream != null)
{
string directory = Path.GetDirectoryName("C:/WebApps/MyApp/Scripts/");
using (Stream file = File.OpenWrite(directory + "MyScript.js"))
{
CopyStream(stream, file);
}
stream.Dispose();
}
And the code for CopyStream method:
private static void CopyStream(Stream input, Stream output)
{
byte[] buffer = new byte[8 * 1024];
int len;
while ((len = input.Read(buffer, 0, buffer.Length)) > 0)
{
output.Write(buffer, 0, len);
}
}
You might want to stick all this code in an Application_Start event in your Global.asax. You don't want it to run for each request
Now getting a reference to your Assembly is a different matter, there are many ways. One way is to include all the above code in your Assembly in question, then make sure you reference that Assembly from your main WebApp project in Visual Studio, then get a reference to the currently executing Assembly like so.
namespace My.Project
{
public class ResourceLoader
{
public static void LoadResources()
{
Assembly myAssembly = Assembly.GetExecutingAssembly();
// rest of code from above (snip)
}
}
}
Then call ResourceLoader.LoadResources() from your Application_Start event in your Global.asax.
Hope this helps
Fully working example (I hope):
namespace TestResources.Assembly
{
public class ResourceLoader
{
public static void LoadResources()
{
Assembly myAssembly = Assembly.GetExecutingAssembly();
Stream stream = myAssembly
.GetManifestResourceStream("TestResources.Assembly.CheckAnswer.js");
if (stream != null)
{
string directory = Path.GetDirectoryName("C:/WebApps/MyApp/Scripts/");
using (Stream file = File.OpenWrite(directory + "MyScript.js"))
{
CopyStream(stream, file);
}
stream.Dispose();
}
}
private static void CopyStream(Stream input, Stream output)
{
byte[] buffer = new byte[8 * 1024];
int len;
while ((len = input.Read(buffer, 0, buffer.Length)) > 0)
{
output.Write(buffer, 0, len);
}
}
}
}
Some caveats:
Change "C:/WebApps/MyApp/" to wherever your web app is located, maybe write some code to work this out dynamically
Make sure the /Scripts folder exists in your webapp root
I think it will overwrite the 'MyScript.js' file if it already exists, but just in case you might want to add some code to check for that file and delete it
Then stick a call to this code in your Global.asax file:
protected void Application_Start()
{
ResourceLoader.LoadResources();
}
Then the path for your web site will be /Scripts/MyScript.js eg:
<head>
<!-- Rest of head (snip) -->
<script type="text/javascript" src="/Scripts/MyScript.js"></script>
</head>