Convert blob to file

Question

I need to convert a blob to file i javascript.

Im using File API

var blob = new Blob(byteArrays, { type: contentType });

This is r

Answer 1

I solved the file problem like this:

    function base64ToFile(base64Data, tempfilename, contentType) {
    contentType = contentType || '';
    var sliceSize = 1024;
    var byteCharacters = atob(base64Data);
    var bytesLength = byteCharacters.length;
    var slicesCount = Math.ceil(bytesLength / sliceSize);
    var byteArrays = new Array(slicesCount);

    for (var sliceIndex = 0; sliceIndex < slicesCount; ++sliceIndex) {
        var begin = sliceIndex * sliceSize;
        var end = Math.min(begin + sliceSize, bytesLength);

        var bytes = new Array(end - begin);
        for (var offset = begin, i = 0 ; offset < end; ++i, ++offset) {
            bytes[i] = byteCharacters[offset].charCodeAt(0);
        }
        byteArrays[sliceIndex] = new Uint8Array(bytes);
    }
    var file = new File(byteArrays, tempfilename, { type: contentType });
    return file;
}

Next problem is the format that angular-file-upload is reading the file in..

Answer 2

In IE10 there is no File constructor, but you can use the following in typescript:

private createFile(bytes: string, name: string): File {
    const file: File = <File>Object.assign(new Blob([bytes]), { lastModifiedDate: new Date(), name: name });
    return file;
  }

Answer 3

It's easy:

var blob = new Blob(byteArrays, { type: contentType });
var file = new File([blob], filename, {type: contentType, lastModified: Date.now()});

or just:

var file = new File([byteArrays], filename, {type: contentType, lastModified: Date.now()});

The code works in Chrome and Firefox, but not IE.

Answer 4

in Edge and Safari, just use blob structure:

var blob = new Blob(byteArrays, { type: contentType });
blob.lastModifiedDate = new Date();
blob.name = name;