Discussions about modularity are recurrent. Some people say that each function should be a separate module/file/package; others say that methods should be contained by a package and grouped by similarity/concerns; and there is still a 3rd group that thinks that a single namespace is the way to go. I will try to explain the design decisions that influenced the creation and current structure of moutjs and why single function packages are not always the best solution.
I’ve been using amd-utils on almost all my projects and sometimes I find myself wanting to use some of the methods on my node.js programs as well, so I decided to write a tool to convert the modules automatically.
The tool uses Esprima internally so it will keep the indentation, comments and it should work as long as the code can be parsed by Esprima. It will do as few replacements as possible to avoid undesired side effects.
Let’s start with an overly simplified/generalized and mostly wrong history of the JS community during the past decade.
Now back to 2012. Everybody knows that augmenting built-in native objects is a bad thing, specially host objects. Polluting the global namespace is also considered a bad practice and many people avoid it as much as possible. It is not uncommon to see people adding their own application code into objects that they don’t own, proving that they don’t really understand why they shouldn’t have globals to begin with, but at least we are moving towards the right direction. <rant>Polluting any namespace is a BAD thing, not only the global scope, you should NOT put your application code into the
$ object…</rant> Script loaders and package managers are becoming more popular each day, node.js is the buzzword of the moment and Harmony might become a reality and provide a native module format.
OK, no more history… Let’s see some code.
The RequireJS behavior changed from version 1.0 to 2.0. Now module dependencies are only loaded after a explicit
require() call or if it is on the dependency tree of some of the
require‘d modules. That means that the module factory (
define callback) won’t execute unless it is needed. That is a huge win for many reasons, less work for the JS engine and code has the same behavior before and after build. It also makes it possible to create alias to complex modules without triggering a download.
On my current project I have ~15 JS widgets that can be placed on any page and the amount of JS required by each widget is small so it makes sense to bundle all the JS into a single file for production (<30KB minified + gzipped excluding jQuery) instead of loading things on demand (a single request have better perf results than multiple requests in many cases).
I will show a very simple technique I used on the project to create an alias to the Google Maps API since I think it can be useful to other people as well in different contexts.
This post was going to be about the Math utilities present on AMD-Utils. Some of them are essential to my day-to-day work and simplify the code structure a lot.
I was going to explain how to use them (which is very easy) but most importantly, why they are useful and when to use them. But instead of publishing it as a post I decided to update the docs and add all the info there so everything is centralized.
I recommend that you try to understand these methods and which kind of problems they try to solve. They are all very trivial to implement but of an extreme usefulness depending on the kind of project you are building. I also think that some of them changed the way I approach some kinds of problems. I use them so much that it’s hard to imagine coding something complex without something similar (I coded the methods clamp/loop/lerp/norm a million times).
So jump over to the docs and understand how to (ab)use these helpers. Even if you are not using amd-utils you can check the source code and implement it by yourself or extract the methods. Most of them are common knowledge but I feel that not that many people know how to use them properly or outside of the regular context, that’s why I thought some explanation would be helpful.