Web/API/HTMLCanvasElement/mozFetchAsStream

ObsoleteThis feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.

The HTMLCanvasElement.mozFetchAsStream() internal method used to create a new input stream that, when ready, would provide the contents of the canvas as image data. However, this non-standard and internal method has been removed.

Syntax

void canvas.mozFetchAsStream(callback, type);

Parameters

callback

An nsIInputStreamCallback.

type Optional

A DOMString indicating the image format. The default type is image/png.

Return value

None.

Examples

Save to disk with mozFetchAsStream (Chrome context only)

This technique also converts it to ico, however it will not work in Windows XP as WinXP cannot convert from PNG to ICO. It saves to the desktop it uses FileUtils.jsm. Also uses NetUtil.jsm

var canvas = document.getElementById('canvas');
var d = canvas.width;
ctx = canvas.getContext('2d');
ctx.beginPath();
ctx.moveTo(d / 2, 0);
ctx.lineTo(d, d);
ctx.lineTo(0, d);
ctx.closePath();
ctx.fillStyle = 'yellow';
ctx.fill();

var netutilCallback = function() {
    return function(result) {
       if (!Components.isSuccessCode(result)) {               
          alert('FAILED to create icon');
       } else {
           alert('succesfully made');
       }
    };
}

var mfasCallback = function(iconName) {
    return function(inStream) {
       var file = FileUtils.getFile('Desk', [iconName + '.ico']);
       var outStream = FileUtils.openFileOutputStream(file);
       Cu.import('resource://gre/modules/NetUtil.jsm');
       NetUtil.asyncCopy(inStream, outStream, netutilCallback());
    }
}

canvas.mozFetchAsStream(mfasCallback('myIcon'), 'image/vnd.microsoft.icon');

Specifications

Not part of any specification.

Browser compatibility

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
mozFetchAsStream Deprecated'Non-standard'	Chrome No support No	Edge No support No	Firefox No support 13 — 43	IE No support No	Opera No support No	Safari No support No	WebView Android No support No	Chrome Android No support No	Firefox Android No support No	Opera Android No support No	Safari iOS No support No	Samsung Internet Android No support No

Legend

No support  

No support

Non-standard. Expect poor cross-browser support.'

Non-standard. Expect poor cross-browser support.

Deprecated. Not for use in new websites.'

Deprecated. Not for use in new websites.

See also

• The interface defining it, HTMLCanvasElement.

HTMLCanvasElement.mozFetchAsStream() by Mozilla Contributors is licensed under CC-BY-SA 2.5.