Instantiating Blobs in dartlang - dart

Question

I've been struggling to instantiate Blobs in dartlang as of late, but i worked out how to do it in version 8640
For those interested (I couldn't find an example anywhere on the net)
I did this:
HttpRequest req = new HttpRequest();
FileReader fileReader = new FileReader();
req.open("GET", "http://...", true);
req.responseType="blob";
req.overrideMimeType("image/png");
req.on.load.add( (event) {
if(req.readyState==4) {
Blob blob = req.response; // note NOT req.responseBlob
fileReader.on.load.add( (evt) {
document.query('#myimage').src=evt.target.result;
});
fileReader.readAsDataURL(blob);
}
});
req.send();
I hope this helps somebody :)

Answer 1

If anyone landed here trying to figure out how to call the Blob constructor like I did, you actually need to feed it a list of lists (i.e. a List<List<int>>).
So, if you have a list of integers:
var binary = [1, 2, 3];
You pass it to the Blob constructor thusly:
var blorp = new Blob([binary]);
Calling var blorp = new Blob(binary); will result in a confusing message, claiming that the constructor wants a String.

Answer 2

From the answer embedded in the question above:
HttpRequest req = new HttpRequest();
FileReader fileReader = new FileReader();
req.open("GET", "http://...", true);
req.responseType="blob";
req.overrideMimeType("image/png");
req.on.load.add( (event) {
if(req.readyState==4) {
Blob blob = req.response; // note NOT req.responseBlob
fileReader.on.load.add( (evt) {
document.query('#myimage').src=evt.target.result;
});
fileReader.readAsDataURL(blob);
}
});
req.send();