Image Blob URL from already given Image Blob URL - javascript

I have a doubt with image blob,is it possible to create an Image blob URL with a given image blob URL?
I created a new image blob URL and tried to use it on img tag but it did not work:
I think maybe the error is because of i am creating new Blob inside useEffect !!! ? IDK
Please help me.
useEffect(() => {
if (socket.current) {
socket.current.on("msg-recieve", (msg) => {
const RecieveBlob = new Blob([msg], { type: 'image/jpeg' });
const RecieveImageURL = URL.createObjectURL(RecieveBlob);
console.log("msg recieved is ", msg)
setArrivalMessage({ fromSelf: false, message: msg })
})
}
setNoImage(false)
}, [])
In this code, msg is an image blob URL coming from the server and I want to display that image in the page. Therefore, I created new Image blob from it. However, when I use the new Image blob it is not working.
If anybody knows why please help me, Thanks.

If the msg is String you shouldn't wrap that in brackets because it makes it an [String] or Array of strings so try this:
instead of:
const RecieveBlob = new Blob([msg], { type: 'image/jpeg' });
write:
const RecieveBlob = new Blob(msg, { type: 'image/jpeg' });
P.S. But I think you can use the blob URL and set it as an image source in the first place, it would work.

Related

Converting dataURI to file for upload via REST does not work but normal filefield upload works fine

I have implemented a solution that accepts a single file upload (image for profile) in a Django Rest Framework backend. This route api/people/id/upload_image. Only accepts a parameter with an image. and can be used via HTTP POST.
When uploading via a fileinput field in eg. Postman, the default Django API or via browser fetch() in my Vue.js application is no problem. So it seems as long as it is a default form-upload field it is doing its job.
But in my frond-end (vuejs 3) I am using an image-cropper. Users can upload an image and via the javascript cropper the image can be cropped. This is important for the UI because I need a square image. The cropper uses HTMLCanvasElement.toDataURL() as export format.
And what seemed to be not that difficult gets me stuck for days now. I just can't find a way to convert and POST the cropped image in such a way that is accepted by the upload_image API backend. I am using Fetch() for sending this POST call.
I am not a javascript expert so I get my knowledge via internet and I tried it in several ways; with first creating a BLOB from the dataURI, and by creating a File before feeding it to dataForm and send it as :body in Fetch()
The dataURI seems OK because I am also replacing the cropped image directly in the HTML. And that looks totally fine. The API is responding with an 'HTTP 200 OK'. But the old image is not being replaced.
So my assumption is that there is something wrong with the image send to the API, because via normal fileupload everything works fine. How should I convert this dataURI in a proper way so it can be send and accepted by the API endpoint. And how should the API call look like: headers, body..
this is my last attempt in converting and sending the cropped image: (dataURIimage is OK)
uploadPhoto(context, dataURIimage) {
const blob = dataURItoBlob(dataURIimage);
const resultFile = new File([blob], "picture", {
type: "image/png"
});
const formData = new FormData();
formData.append("image", resultFile);
const headerToken = "Token" + " " + this.getters.getToken;
const url =
"https://workserver-7e6s4.ondigitalocean.app/api/people/" +
this.getters.getProfiel.id +
"/upload_image/";
fetch(url, {
method: "POST",
headers: {
'Content-Type': 'multipart/form-data',
'Authorization': headerToken,
},
body: formData,
})
.then(function(response) {
console.log(response.status)
if (response.ok) {
return response.json();
}
})
.then(function(data) {
console.log(data.image);
})
.catch(function(error) {
alert(error + " " + ":ERROR");
});
},
function dataURItoBlob(dataURI) {
// convert base64 to raw binary data held in a string
// doesn't handle URLEncoded DataURIs - see SO answer #6850276 for code that does this
var byteString = atob(dataURI.split(',')[1]);
// separate out the mime component
var mimeString = dataURI.split(',')[0].split(':')[1].split(';')[0];
// write the bytes of the string to an ArrayBuffer
var ab = new ArrayBuffer(byteString.length);
var ia = new Uint8Array(ab);
for (var i = 0; i < byteString.length; i++) {
ia[i] = byteString.charCodeAt(i);
}
return new Blob([ab], { type: mimeString });
}
Martijn dekker

How to convert node.js array-buffer to javascript array buffer

I send audio to client using node.js :
res.send(audio); / audio it is the buffer array
And I get object 'arrayBuffer' in data.
And I conver it to Blob and after to file (I want to get dataURL to show it in player)
.then(
(result) => {
result.arrayBuffer().then(function (data) {
const blob = new Blob([data], { type: 'audio/wav' });
var fileReader = new FileReader();
fileReader.readAsDataURL(blob);
fileReader.onload = function (evt) {
// Read out file contents as a Data URL
var url = evt.target.result;
res({blob, url})
};
})
}
)
And it works good. I use this url it as src of my <audio> attribute and it works.
But now I want to send this file from server as a part of json. Now I get audioBuffer from the serve in "audio" property. I chage arrayBuffer method to json in fetch:
result.json().then(function (data) {
const blob = new Blob([data.audio], { type: 'audio/wav' });
...
But now it doesn't work. I tried to use module www.npmjs.com/package/to-array-buffer to convert data.audio to js-arrayBuffer, but it doesn't help.
Maybe you know what's problem here?
Ok, I solved problem. I use module about whick I wrote to-array-buffer, but I use not toArrayBuffer(data.audio) but toArrayBuffer(data.audio.data)

How to get a File() or Blob() from an URL in javascript?

I try to upload an image to the Firebase storage from an URL (with ref().put(file))(www.example.com/img.jpg).
To do so i need a File or Blob, but whenever I try new File(url) it says "not enough arguments“…
EDIT:
And I actually want to upload a whole directory of files, that’s why i can’t upload them via Console
Try using the fetch API. You can use it like so:
fetch('https://upload.wikimedia.org/wikipedia/commons/7/77/Delete_key1.jpg')
.then(res => res.blob()) // Gets the response and returns it as a blob
.then(blob => {
// Here's where you get access to the blob
// And you can use it for whatever you want
// Like calling ref().put(blob)
// Here, I use it to make an image appear on the page
let objectURL = URL.createObjectURL(blob);
let myImage = new Image();
myImage.src = objectURL;
document.getElementById('myImg').appendChild(myImage)
});
<div id="myImg"></div>
As of July 2022, the fetch API has about 97% browser support worldwide, with basically just IE missing it. You can get that to near 100% using a polyfill, which I recommend if you're still targeting IE.
#James answer is correct but it is not compatible with all browsers. You can try this jQuery solution :
$.get('blob:yourbloburl').then(function(data) {
var blob = new Blob([data], { type: 'audio/wav' });
});
It did not work until I added credentials
fetch(url, {
headers: {
"Content-Type": "application/octet-stream",
},
credentials: 'include'
})
async function url2blob(url) {
try {
const data = await fetch(url);
const blob = await data.blob();
await navigator.clipboard.write([
new ClipboardItem({
[blob.type]: blob
})
]);
console.log("Success.");
} catch (err) {
console.error(err.name, err.message);
}
}
If you are using homepage in package.json then ypu have to use:
CurrentUrl: http://localhost:3008/tempAppHomepageFromPackageJson/
const file: File = this.state.file;
const localUrlToFile = URL.createObjectURL(file);
const fileHash = localUrlToFile.split('/');
const objectUrl = location.href + fileHash[fileHash.length - 1];
objectUrl is the local url to file. For example to show in runtime you uploading file.
Second solution is (if you have no homepage in package.json):
const file: File = this.state.file;
const objectUrl = window.URL.createObjectURL(file);
Third solution (Not working in safari):
const file: File = this.state.file;
let reader = new FileReader();
reader.readAsDataURL(file);
const objectUrl = reader.result as string;
Enjoy ;)

Retrieve image file from url using JS / Angular

Im working on exporting data from a wordpress environment to a MongoDB using MongooseJS as data model bridges. I've got a JSON with every objects including all required information.
As a example, I've got user item including an avatarpath field pointing to the wordpress server url: (ex: http://url/wp-content/upload/img/avatar.jpg)
What I would like to do it retrieving the image from its url, upload it to my new storage folder, retrieve the new path, and store the new object in my mongodb.
My issue is that I can't manage to find a way to get the file data from a http get or any other way. Usually, I've got a file input in my html, and I start from the file object from this input. How should I proceed to make this work? Am I going into the wrong direction?
I've found this answer but it seems deprecated:
how to upload image file from url using FileReader API?
Here is what I've got for now:
$scope.curateurs_data = {};
$scope.curateurs = [];
$http.get('resources/json_curateurs.json').success(function(data) {
$scope.curateurs_data = data;
console.log(data[0]);
$scope.getPics();
});
//RETRIEVE IMAGE DATA
$scope.getPics = function(data){
console.log("RETRIEVING PICTURE")
var uploadPlace = '/upload/user';
var images;
angular.forEach($scope.curateurs_data, function(item, key) {
$scope.curitem = item;
console.log($scope.curitem);
$http.get(item.avatarpath, {responseType: "arraybuffer"}).success(function(data){
var arrayBufferView = new Uint8Array( data );
var blob = new Blob( [ arrayBufferView ], { type: "image/png" } );
var urlCreator = window.URL || window.webkitURL;
var imageUrl = urlCreator.createObjectURL( blob );
console.log(imageUrl);
console.log(blob);
images = blob;
var pic = {
images: images
};
Upload.upload({
url: uploadPlace,
arrayKey: '',
data: pic,
}).then(function(response) {
// Adding data paths to formData object before creating mood
// MUST respect images array order
$scope.curitem.avatarpath = response.data.files[0].path;
console.log(response.data.files[0].path);
});
}).error(function(err, status){})
$scope.curateurs.push($scope.curitem);
});
}
I've also tried something like this but I can't seems to make it work as well.
$http.get(item.avatarpath,{responseType: "blob"}).
success(function(data, status, headers, config) {
// encode data to base 64 url
fr = new FileReader();
fr.onload = function(){
// this variable holds your base64 image data URI (string)
// use readAsBinary() or readAsBinaryString() below to obtain other data types
console.log( fr.result );
};
fr.readAsDataURL(data);
console.log(fr.readAsDataURL(data));
}).
error(function(data, status, headers, config) {
alert("The url could not be loaded...\n (network error? non-valid url? server offline? etc?)");
});
Use node's http object on the backend to download the image. Something like:
http.request(url, function(response) {
// Your code to write the file out or store it in the database here.
});

How to download image from a url in chrome app using chrome filesystem api?

I have a url which has a image. I want to download that image using chrome api. I am developing a chrome app and not extension.
Can anyone please tell me where i am going wrong??
My code:
service('fileService', function($window){
this.saveUserInfo = function(theFilePath) {
// filepath is the url passed from controller{
// Get the directory entry stored (if any).
var fileUrl = "";
var config = {
type: 'saveFile',
suggestedName: 'TheBee.png',
accepts:[{extensions: ['png', 'jpg', 'jpeg']}]
};
chrome.fileSystem.chooseEntry(config, function(writableEntry) {
chrome.fileSystem.getWritableEntry(writableEntry, function(entry1) {
entry1.getFile(theFilePath, {create:true}, function(entry2) {
entry2.createWriter(function(writer) {
var blob = new Blob({type: 'image/png'});
writer.write(blob);
});
});
});
});
});
});
Change
var blob = new Blob({type: 'image/png'});
To
var blob = new Blob([entry1],{type: 'image/png'});
The Blob contructor acceptes blob parts: MSDN=> Blob(blobParts[, options])
You cannot use getFile on entry1 because it is a file itself. You will need to change config.type to "openDirectory"
You also need to add an empty array as the first input to the blob constructor.

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