May 27

Object Oriented Design is all fine and dandy, but how about thinking about the real world?

Tech with tags: 3 Comments »


Rich Hickey (Clojure creator) gave one of the best talks that I have been in for awhile. The title of the talk was scarily low level and “wow this must be boring”-y, but the title should have been something like “Learn about how the real world works”.

The first part of the talk discussed philosophy and how our software is totally messed up due to us not taking the factor of time into account properly. So many functional programming talks go into the bizarreness of Monad details and the like, in a way that makes a non-Functional chap’s head blow up.

Rich on the other hand didn’t go there. No need to say “Monads are in Haskell as an escape hatch past the whole state issue”. Instead he discussed the general notion of time and how it relates to variables. Short version: variables are variable in that they change over time, so really we want immutable values with different ones at different points. He talked about the different notions of time (before, at the same time, after, now, etc) and how the concurrency / thread problems become a touch more obvious when you think about things in that way.

And it went on from here. He talked about the great design of the data structures in Clojure and how they almost always uses a nice multiple version control system that enables a lot of things to “just work” in a concurrent and safe way. And of course, you have to have a little bit of fun with the Java Data API and how you can do things like someDate.setMonth().

This is the kind of talk that will make you think differently about your code, even if you are not in functional world. You will think about taking value snapshots to work with instead of passing around quite so many references. It was highly entertaining and will have me thinking for quite some time.

Related Interview: Rich Hickey on Clojure’s Features and Implementation

In this interview taped at QCon London 2009, Rich Hickey talks about all things Clojure: Software Transactional Memory, concurrency, persistent data structures, ports, AOT compilation, and more.

May 26

Icky? Using strings to add legacy features in languages

JavaScript, Tech 6 Comments »


A contingent in the JavaScript community is pretty much solely focused on securing the language. Security is always important, but even more-so when you are dealing with a language that runs in a user agent to run the Web.

Whenever you try to add a feature to a language you are instantly dealing with legacy and backwards compatibility.

Perl has a strict mode that is very popular in the community. I remember projects where if I checked in a module without use strict; and -w I would get beaten up.

Back to JavaScript, how can we apply stricter rules on what we do in the JavaScript runtime after the face? One solution that the ECMAScript Edition 5 folks came up with is borrowing use strict but since they couldn’t add it to the language itself, they have you put it in a string "use strict";. You can place it at the top of the file, or even as the first statement in a function.

I find it incredibly ugly, yet pragmatic. It works.

However, then I saw some new items:

"use strict,cajita";

And currently you can’t switch the order around? It looks for absolute keys? That seems a little crazy. Surely all of these should be possible:

"use cajita,strict";
"use strict,cajita";
"use strict";
"use cajita";

Then this little pragmatic hack starts to get real messy. I start to joking imagine a ludicrous world like this:

(function() {
  "use strict";
  "use let"; // let's get let in there!
  "use cramda"; // I love Alex's cramda, let me use it!
  "use e4x"; // XML inline. Screw templates
  // If I see a var with the same name, REALLY use let instead
  "let x;"
  var x;
  // Now I can use the cramda
  "x = #(a, b) { "\
  " ... logic here ... "\
  // And the let... ironic that it is in a string now
  "let y = <xml></xml>";
  // Annotations come to JavaScript!
  function someThing() {}

I like to think of myself as pragmatic, but why do I feel so cranky about "use strict";? :)

May 20

Write Once, Pwn Everywhere…. oh and Jetpacking around

Java, JavaScript, Tech with tags: 3 Comments »

By now you have probably read about the critical Java vulnerability and how easy it is to take over a machine from a web page via a Java applet.

Apparently, Sun fixed it fairly quickly, but even then some people say their fix was too specific and thus there are still problems. Apple on the other hand, were not diligent and are still yet to provide a fix. Ouch.

Painful news as JavaOne approaches and Sun tries to push JavaFX. I was trying to think of a Java applet that I have used (knowingly) in the recent past, and I think the only candidate is the Facebook photo uploader.

I have been watching some research for a talk on JavaFX and I am really torn. In theory, the Java platform is phenomenal and should be a great choice for doing this kind of development. The scene graph work in JavaFX is very nicely done, but the implementation seems to be a touch off in much of what I have seen. Scrolling causing the applet to go blank? Browser crashes? Ouch. But, JavaFX is new, and has a chance to get better. Their problem is that they are squeezed from both sides. The browser platform itself is accelerating quickly, and it has the advantage of being native. Once you go to plugin land you are competing with Flash with its large share and proven ability.

Getting webby

I find myself wanting to get more and more webby. This is why I was excited to work with the Jetpack project that we just launched today at Mozilla Labs. Being able to extend the browser using Web technology itself is going to open the door for more playing. People have created 7000 addons for Firefox alone, but as someone who has done a touch of XUL, I am happy to stay in my familiar territory of HTML, CSS, JS. Jetpack has just been born, and is incredibly early stage, but I can’t wait to see it grow and get the APIs that people want in a secure extensible model.

You will see a lot of Bespin in there too. Below is a screencast where I create a Jetpack feature on the fly (no reloads!) using Bespin, and once you install Jetpack it embeds the puppy into the tutorial and the developer area too. Much more than can be done though!

May 15

Bespin gives you some Pie and will do more Web Work for you

Bespin, Tech, UI / UX with tags: , , 2 Comments »

There have been a couple of things that have been really fun to see and work on in Bespin recently.

First up, is our new Pie Menu that Ben just posted on. The short reasons why I like the new look are:

  • Giving as much area to your code as possible. Why show a command line all the time when you only need it when you run commands? Why have headers and subheaders?
  • Pushing the boundaries on subtle animated effects that full screen change the bits “on the glass”

The implementation is interesting too. We took the nice animation and easing functions that Dojo already provides, but instead of it powering the DOM, we hook in and have it power our Canvas animations instead.

For example, to show an incoming animation we use a fadeIn effect with the backOut easing. In onAnimate we use the opacity setting that the animation provides to render our own animation:

var anim = dojo.fadeIn({
    node: { // fake it out for Dojo to think it is changing the style :)
        style: {}
    duration: 500,
    easing: dojo.fx.easing.backOut,
    onAnimate: function(values) {
        var progress = values.opacity;

Here you can see it in action in video form:

Or, go to the live sample.

We are excited to pump up the “fun” in the UI (with options to tone it down of course). Once nice side effect is that the editor component will have this all baked in, so where ever you see a Bespin, you will be able to access the features you want.

Web Workers; Not having them do too much

Malte Ubl continues to do much appreciated interesting work for the Bespin project. His facade around Web Workers is good stuff.

Since we are trying to push the boundaries of the Web hard, and giving some sexy to the UI, we need to make sure that we keep responsiveness as the highest priority, else users will go nuts.

Web Workers give us the ability to do a lot more in Bespin, but outside of the main browser “thread”. For example, doing real-time analysis on the code itself (e.g. setsyntaxcheck all). The problem that we ran into as we started to use Workers for this type of thing, was making sure that we weren’t killing the poor CPU. It is all well and good to fire off work to a Worker, but how many are running crunching? Malte has done work to make sure that the CPU fan doesn’t go nuts if you are doing a lot of work, and this is something that people will have to generally work around as they start to do more and more in their Web applications. It may be nice in the future to have a richer API that you could use to time slice your background tasks in a better way, as there is a lot of work that fits into the “kick this out and run at your convenience” mould.

Malte recently posted on how added support for the Bespin event loop into the Workers themselves. This is really nice as a Bespin developer as you can use the same publish/subscribe event metaphor, and the Worker facade handles it all for you, so you can talk across the boundaries. This hugely changes the amount of code that you have to write.

He also added support to help the asynchronous issues around “Can you fire this, but make sure that it only fires after foo, bar, and baz are all fired”. We will probably need to cache certain published events so we don’t get into a situation where you run this code after a main initialization event has fired, and thus you will never see it again.

Building a Web application using the latest and greatest HTML5 features is a lot of fun, and we hope that developers will like it too.

May 07

Who do I trust with my Identity? Erm, how about me? OpenID Weaves into the browser!

Tech 1 Comment »

my profile

I was incredibly excited to see Dan Mills of the Weave team show off OpenID in the browser thanks to Weave. I have wanted this from long before joining Mozilla and Dan has done a great job and doing something smart to make it happen.

The key to this all is the notion of “logging into the browser.” With the Weave project this is exactly what you do. Although the first service that Weave offered was the ability to sync bookmarks, all along it has been setup for much much more, and this is a perfect example of what the integration of a browser with a service backend can mean. One thing to note is that the Weave team really cares about privacy. The way the Weave system works right now is that the server has encrypted bits that it can never look at and understand. Instead, the client itself has the private keys that it needs to do the real work of holding the data, thus the browser, which is a natural extension to yourself the user, has full control. Think about how that differs from many services up in the cloud that make a lot of money off of your data (not that making money is bad!)

Back to the point at hand. Dan shows us how, once you are logged into Weave (and thus the browser) it will watch out for input’s that match the openid spec (openid_identifier, openid_url) and replaces it with a simple button that tells you that you can just log in! With a click on the button you get logged in automatically via Weave and you are on your way. Now Ben will be able to login to the Web 2.0 Expo site with one click instead of a series of nightmare steps. I think this is a pretty big deal.

Here it is in action:

Weave ID video screencast

In one fell swoop we get:

  • A usable login procedure that is trivial!
  • We don’t have to give trust to some third party site that we are giving the keys to the treasure too. Imagine if you used OpenID to login to your bank… would you trust your OpenID provider enough for that?
  • It is important to note that they also integrated the Firefox password manager into the mix. This means that you can set auto login right from the URL bar widget (with your password, as well as with OpenID!)

Of course, this is early days, as Dan says in his post

Keep in mind that this is just a prototype that we hacked together in a few of days, so there are some very rough edges. But we’re super excited about the possibilities already. When demoing it to people, they said things like “whoa! how did you do that?” and “I want this! How do I get it?”

The answer is, “soon”, or if you’re brave enough you can try it out right now by installing the latest Weave development snapshot. Please let us know what you think by posting on the Weave forum!

People and Places

Now we are getting the notion of “people” and Identity in the browser, and we also have “location” too, we are really getting somewhere. A great week!