Is there a function for appending blob data in JavaScript
I currently use the following approach:
var bb = new Blob([Hello world, 2], { type: text/plain });
bb = new Blob([bb, ,another data], { type: text/plain });
And BlobBuilder function is not available in Chrome.
Blobs are immutable so you can't change one after making it. Constructing a new Blob that appends the data to an existing blob (as you wrote in your initial question) is a good solution.
If you don't need to use the Blob each time you append a part, you can just track an array of parts. Then you can continually append to the array and then construct the Blob at the end when you need it.
var MyBlobBuilder = function() {
this.parts = [];
}
MyBlobBuilder.prototype.append = function(part) {
this.parts.push(part);
this.blob = undefined; // Invalidate the blob
};
MyBlobBuilder.prototype.getBlob = function() {
if (!this.blob) {
this.blob = new Blob(this.parts, { type: text/plain });
}
return this.blob;
};
var myBlobBuilder = new MyBlobBuilder();
myBlobBuilder.append(Hello world, 2);
// Other stuff ...
myBlobBuilder.append(,another data);
var bb = myBlobBuilder.getBlob();
