I am trying to display image while editing imformation but could not do it. I am getting below response from server.
ÿØÿàJFIFÿÛC
%# , #&')*)-0-(0%()(ÿÛC
I want to convert this response into Base64 so that I can handle but dont know how to convert it.
Can anyone tell me how to do this?
I am trying to do this but does not work..
response => {
console.log('Media',response)
let base64Data: string;
let reader = new FileReader();
reader.readAsDataURL(response);
reader.onloadend = () => {
base64Data = reader.result;
this.previewURL = this.sanitizer.bypassSecurityTrustUrl(base64Data);
};
You seem to be doing the right thing in the code you posted. May be the data you are getting from the server is corrupted.
For assistance you can check the sample working fiddle here that I created for you.
You can replace the base64Data with your own data in the fiddle and try to verify it.
Related
I am trying to convert an Image from my local files to Base64 by JavaSctipt.
For example please look at THIS website.
When I browse a picture on the input beneath Local File* heading (input having id #form-base64-converter-encode-image-file) and then run this code in the console of the browser -
function getBase64(file) {
var reader = new window.FileReader();
reader.readAsDataURL(file);
reader.onload = function () {
alert(reader.result);
};
reader.onerror = function (error) {
alert('Error: ', error);
};
}
var file = window.document.querySelector('#form-base64-converter-encode-image-file').files[0];
getBase64(file);
The script give me a long string which is supposed to be conversion of image in Base64. But when I assign the string in the source of an Image the image won't show up. The string is corrupted or not a proper conversion of Base64. Please somebody explain what I need to do for a proper Base64 string which I can then assign in src attribute of an < image >
Thank you.
I want to extract the bytecode from an file I select (pdf) to save it in my database. But I am always getting the error that my byte is undefined. Could someone look at my code and tell me what is wrong with it?
I tried to use the FileReader but my byte returns undefined, the formdata works fine it shows on the console every information I need for the file.
EDIT:
uploadFile2(files: FileList | null): void {
const file = files.item(0)
const reader = new FileReader()
reader.readAsDataURL(file)
reader.onload = () => {
this.documentsArray.push({documentType: this.form.controls.dokumentType.value, file: reader.result})
console.log(this.documentsArray)
}
}
Hi I edited my code and now I am getting a base64 I think, but one question, it starts like this:
data:application/pdf;base64,JVBERi0xLjQKJfbk/N8KM......."
is the start with data:application/pdf correct or do I have to change something to save it in the database
I'd suggest you to store the file as a base64 String in your database.
This would look as following. With the line number 2 you're fetching the file from your input event.
const reader = new FileReader();
reader.readAsDataURL(event.target.files[0]);
reader.onload = (event) => {
if (reader.result) {
//save pdf base64 into database
}
I want to make a multiple images upload system with prograss bar. I want to do with simaple code(using jquery or js). I want when user has upload his images on browser and i want to show on browser that images and with upload button he starts uploading image via ajax in his folder.
So questions
1.) Is it possible to show uploaded image (without any complicated code) ?
2.) Do i get a variable or array where uploaded images are stored as base64 code (data:/img:dfd5d/d54fs..... something like this) or encoded?
3.) How do i add progressBar ?
I didn't write any code yet because i dont know how to start. I am new in computer science.
But i find this code on this site
function previewFile() {
var preview = document.querySelector('img');
var file = document.querySelector('input[type=file]').files[0];
var reader = new FileReader();
reader.onloadend = function () {
preview.src = reader.result;
}
if (file) {
reader.readAsDataURL(file);
} else {
preview.src = "";
}
}
This is easy code and i understand but one thing is not clear what does mean this line var reader = new FileReader(); why use new and what is it ?
Ty in advance and please dont explain complicate and i am not very good in english. So please try to explain in poor words if possible..
Assuming that you have this field
<input type="file" onchange="showImage(this)"/>
you can create a script to take the binary data and show it
function showImage(input){
var reader = new FileReader();
// validating...
var fileType = input.files[0].type;
var filesize = input.files[0].size;
// filetype (this will validate mimetype, only png, jpeg, jpg allowed)
var fileTypes = ["image/png", "image/jpeg", "image/gif"];
if (fileTypes.indexOf(fileType) < 0){
// return error, invalid mimetype
return false;
}
// file cannot be more than 500kb
if (filesize > 5000000) {
// return error, image too big
return false;
}
reader.onload = function (e) {
// e will contain the image info
jQuery('#myimagetopreview').attr('src', e.target.result)
}
reader.readAsDataURL(input.files[0]);
}
This should work, if you have problem tell me
edit: FileReader is not supported by all the browsers, check the documentation for more https://developer.mozilla.org/en/docs/Web/API/FileReader
The FileReader in JS has Status "Working Draft" and isn't part of the official JS API. I think you have to wait until the Browsers support this ne API or you have to activate experimental JS API in the Browser.
I am generating a string through JavaScript and I need to download it to a text file with a predefined dynamic filename. This way there will be no room for error by employees.
This is obviously not possible in JavaScript due to security issues. However, from what I have read it should be possible with base64 encoding.
I managed to encode the string and open a url with the decoded data. The string has been decoded successfully in this URL. The format is as follows:
var data = 'data:text/plain;base64,'+L_EncodedData;
document.location = data;
I need to open a file dialog with the decoded data so the employees can download the content generated in this URL.
Any help?
Many thanks in advance
If you're still looking for an answer to this, check out my answer here. This is how I would adapt it for your needs.
// Convert the Base64 string back to text.
var txt = atob(data.reportBase64Bytes);
// Blob for saving.
var blob = new Blob([byteString], { type: "text/plain" });
// Tell the browser to save as report.txt.
saveAs(blob, "report.txt");
If you use this, make sure you grab the polyfills that I mention in the other post.
This block is fixed.
window.OpenWindowForBase64 = function(url, callback) {
var image = new Image();
image.src = url;
var w = window.open("");
w.document.write(image.outerHTML);
if (callback) {
callback(url);
}
}
I've got a drag and drop script that uses readAsArrayBuffer(). The length of the buffer is perfect, but I can't seem to figure out how to pull the data out of the buffer.
Apparently I've got to make a DataView or an Uint8Array or something, then iterate through its byteLength...help!
EDIT
Pertinent code (there's not much of it):
var reader = new FileReader();
reader.onload = function(e) {
// do something with e.target.result, which is an ArrayBuffer
}
reader.readAsArrayBuffer(someFileHandle);
This might change based on your answer to my comment, but if I assume that you are using a FileReader somewhere, you need to read it's result attribute in the loaded callback that you need to provide:
function loaded(evt) {
var datastring = evt.target.result;
// do something here
}
reader.onload = loaded; // where reader is a FileReader, FileReaderSync
Update: Ah, I see. Well then your best course of action is to follow to this duplicate:
Converting between strings and ArrayBuffers
Update2: Note that you could probably use readAsText() then, but I don't know if you're at liberty to do this.