Eli Grey


tinylog is a minimalistic logging platform JavaScript library I created which is primarily intended for online IDEs and implementing console.log() for browsers without native consoles. There is also a lite version intended for embedding in other JavaScript libraries. One such library that embeds tinylog lite is Processing.js, which uses it to implement Processing’s println().

There are also online demos of using tinylog that you can try out. The tinylog saved log viewer demo only works in browsers that support the W3C File API which is only Firefox as of now.

Pausing JavaScript with async.js

async.js is a library that aims to make it so you don’t have to mess with callbacks when making applications in JavaScript 1.7 or higher by using the yield statement to pause function execution.


Please note that user interaction with the page is not blocked during the course of any of these examples.

node.next(eventType) method

The node.next(eventType) method would pause a function until the specified event is fired on the node that next was called on and would return the captured event object.

var listenForNextEventDispatch = function ([node, eventType], callback) {
    var listener = function (event) {
        node.removeEventListener(eventType, listener, false);
    node.addEventListener(eventType, listener, false);
Node.prototype.next = function (eventType) {
    return [listenForNextEventDispatch, [this, eventType]];

You could now do the following in an async()ed function to handle the next click event on the document.

var clickEvent = yield document.next("click");
// handle click event here

Asking the user for their impressions of async.js

The following code does not use any obtrusive and annoying functions like prompt or alert yet still can utilize execution-blocking features.

yield to.request("feedback", "POST", (
    yield to.prompt("What are your impressions of async.js?")
yield to.inform("Thanks for your feedback!");
// do more stuff here

As opposed to the following, which is functionally equivalent to the previous code but doesn’t use async.js’s blocking features.

    ["What are your impressions of async.js?"],
    function (response) {
            ["feedback", "POST", response],
            function () {
                    ["Thanks for your feedback!"],
                    function () {
                        // do more stuff here

That’s a lot of callbacks, all of which are implied when you use async.js.

Creating an async.js module for thatFunctionThatUsesCallbacks

async.yourMethodName = function ([aParameterThatFunctionUses], callback) {
    thatFunctionThatUsesCallbacks(aParameterThatFunctionUses, callback);

You could then use yield to.yourMethodName(aParameterThatFunctionUses) and immediately start writing code that depends onthatFunctionThatUsesCallbacks function after the statement.

Fonts in Processing.js

I recently implemented fully-featured cross-(HTML5-supporting)-browser loadFont() and text() functions in Processing.js. This implementation does not suffer from the limitation of the old implementation that only supported SVG fonts and writing text from already-installed fonts only worked recent Mozilla-based browsers. I also revamped the entire library, fixing a few hundred errors, changing and optimizing many Processing method implementations, and getting rid of all of the implied global variable leaks. Included is an image gallery of the same Processing program being run using Processing and Processing.js. The one showing only the outputted image was saved directly from a canvas element. You can also try out fonts in Processing.js at this demo page. The demo page does not use the same font as in the screenshot but it is similar. If your browser does not support @font-face CSS rules but does support the canvas text API, your system default monospace font will be used instead.

processing-js-loadFont-test-150x150 processing-loadFont-test-150x150

Another E4X DOM library

I just made another E4X DOM library, but this one is intended to implement the optional features in the ECMA-357 standard that are not implemented by Mozilla in JavaScript. The library is named e4x.js due to, for the most part, it only implementing stuff already specified in E4X. The only difference between the standard and my implementation is that the XML.xpath(xpathExpression) method also supports numeric, string, and boolean result types.

E4X DOM toolkit

I have created a small JavaScript toolkit named e4x-dom.js for making it easy to manipulate the DOM with E4X.

The following methods are implemented on XML objects by e4x-dom.js:

Returns the HTML node representation of the XML.
over(element or selector)
Either overwrites element or every element matched by the CSS selector with node().
Same as over(document.getElementById(id)) but also preserves the the id of the element being overwritten in the element replacing it.
fill(element or selector)
Removes every child node of element or every element matched by the CSS selector. Then node() is appended to all of the emptied elements.
Same as fill(document.getElementById(id))
appendTo(element or selector)
Appends node() to element or every element matched by the CSS selector.
Same as appendTo(document.getElementById(id)).
insertBefore(element or selector)
Inserts node() before element or every element matched by the CSS selector.
Same as insertBefore(document.getElementById(id)).
insertAfter(element or selector)
Inserts node() after element or every element matched by the CSS selector.
Same as insertAfter(document.getElementById(id)).

The following are examples of using the toolkit:

var img = <img
 src={prompt("Enter an image URI")}
 alt={prompt("Describe the image")}
<h1>The image was <em>removed</em>.</em>.overId("foobar");
<![CDATA[And then this text node filled the header]]>.fill("#foobar");
// the CDATA isn't itself put into the document but the data inside it is escaped so it
// works in HTML and XHTML
<h1><![CDATA[<html> in here is <escaped>]]></h1>.insertBefore(document.body.firstChild);
// if you just want to create an element quickly, do xml.node()
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"/>.node(); // SVG node
<div/>.node(); // div node
// DOM methods are forwarded to .node()[method]()
<foo bar="baz"/>.getAttribute("bar") === "baz"; // same as getting .@bar
// mass-modifications with CSS selectors
<strong>Absolute links are <em>not</em> allowed</strong>
 .over('a[href^="http://"], a[href^="https://"], a[href^="//"]');
if (user.hasEditPrivileges) {
 // wikipedia-style "put an edit link at the start of each section"
 <a href={"/edit?page=" + page.id}>[edit]</a>.insertAfter('h2');
// <![CDATA[]]> nodes directly accessed are converted to text nodes:
 This is a text node.
 <html> is escaped inside it.

JSandbox 0.2

I have recently released JSandbox version 0.2. JSandbox is a JavaScript sandboxing library. Version 0.2 is, for the most part, a complete re-write. It introduces many new features, such as load (for loading external scripts) and exec (faster than eval but no return value). There is now an additional fixed-position arguments API along with the version 0.1 API.


mumbl is a JavaScript library that makes it easy to play music and create playlists on web pages.


A demo is included with mumbl but if you dont want to download it, there is also an online demo.

Please note that mumbl is not the player in the demo. mumbl is the back-end and the demo is just an example of using mumbl.

Supported Platforms

Supported Platforms

  • HTML5
    • Firefox 3.5+
    • Google Chrome 4+
  • SoundManager 2 (version 2.95b.20100323+)
    • Firefox 1.5+
    • Opera 10+
    • Google Chrome 1+
  • Songbird 1.4+


API documentation can be found in the readme.


  • 0.1.1
    • Better error handling.
    • loaderror event.
  • A while after version 0.1 is released
    • Create a simple library that makes all MP3, OGG, WAV, etc. links be able to be played using mumbl.
    • Make the demo mumbl-powered music player (it will be renamed “mumblr”) portable and reusable.
    • Remove jQuery dependency from mumblr.
    • Make the track title display scroll (maybe using a <marquee>) when it overflows.
  • Version 0.2
    • Full compatability with every major browser.
  • The distant future (maybe version 1.0)
    • Create a simplified flash audio back-end for mumbl that integrates much more nicely and has a smaller file size than SoundManager2.


Yesterday I made a simple JavaScript micro-library named RetargetMouseScroll that provides a simple API to retarget/redirect mouse scroll events. I named it this because RedirectMouseScroll sounded weird. At first glance it seems pretty useless but there are some cool things you can do with the library which are listed in the examples section of this post.


The test suite functions as a great demo.


    element         :Node,    // default: document
    targetWindow    :Window,  // default: window
    preventDefault  :Boolean, // default: true
    scrollMultiplier:Number   // default: 1.0

RetargetMouseScroll returns an object containing a restore method. Calling the method restores the default scrolling.


  • RetargetMouseScroll(myElement, myFrame) – Per-element mouse scroll retargetting to a frame
  • RetargetMouseScroll(document, window, true, 0.5) – Slow down scrolling
  • RetargetMouseScroll(document, window, true, -1) – Invert scrolling
  • RetargetMouseScroll(document, window, true, 2) – Speed up scrolling

More advanced example using a popup:

var win = window.open("/", "example", "w=" + (screen.availWidth / 3.5)
                                      + ",h=" + (screen.availHeight / 3.5)
                                      + ",scrollbars=yes,resize=yes");
win.addEventListener("DOMContentLoaded", function() {
    var retargetting = RetargetMouseScroll(document, win);
    win.onunload = function () {
}, false);

In the previous example, all mouse scrolling on the main document is retargetted to the popup until it is closed.