Skip to main content

0x0002 Dev Diaries - JS Privates

A little experiment / toy I have, which I might use to keep some decoupling attempts straight.



Using this, I'll be able to allow the various components to maintain properties on other objects they work with, safely, without interfering with one another.


For example, I have a Draggable behavior that can be enabled in a scene and allows objects in the scene to be, obviously, draggable. During this use, the behavior code may often need to set properties on the objects to track dragging state, but needs to do so without interfering with other behaviors setting properties of their own, even other instances of the same behavior. This simple utility enables this.

privates(this, entity).dragPath = [];
privates(this, entity).dragPath.push(curPos);


...


drawPath(privates(this, entity).dragPath);


The concept this is trying to express is that the first object owns a set of private properties attached to the second object, and this works much like private attributes in many languages but works with delegation and composition, rather than inheritance.


My rendering system will be using this to take the general description of a sprite object and attach to it loaded images, animation state, and flags needed to manage redraw orderings, without mucking in the namespace of the object itself.

Comments

Nathaniel Smith said…
this is neat. thanks for sharing. it's a lot of power for a little code.

Popular posts from this blog

CARDIAC: The Cardboard Computer

I am just so excited about this. CARDIAC. The Cardboard Computer. How cool is that? This piece of history is amazing and better than that: it is extremely accessible. This fantastic design was built in 1969 by David Hagelbarger at Bell Labs to explain what computers were to those who would otherwise have no exposure to them. Miraculously, the CARDIAC (CARDboard Interactive Aid to Computation) was able to actually function as a slow and rudimentary computer.  One of the most fascinating aspects of this gem is that at the time of its publication the scope it was able to demonstrate was actually useful in explaining what a computer was. Could you imagine trying to explain computers today with anything close to the CARDIAC? It had 100 memory locations and only ten instructions. The memory held signed 3-digit numbers (-999 through 999) and instructions could be encoded such that the first digit was the instruction and the second two digits were the address of memory to operat...

Announcing Feet, a Python Runner

I've been working on a problem that's bugged me for about as long as I've used Python and I want to announce my stab at a solution, finally! I've been working on the problem of "How do i get this little thing I made to my friend so they can try it out?" Python is great. Python is especially a great language to get started in, when you don't know a lot about software development, and probably don't even know a lot about computers in general. Yes, Python has a lot of options for tackling some of these distribution problems for games and apps. Py2EXE was an early option, PyInstaller is very popular now, and PyOxide is an interesting recent entry. These can be great options, but they didn't fit the kind of use case and experience that made sense to me. I'd never really been about to put my finger on it, until earlier this year: Python needs LÖVE . LÖVE, also known as "Love 2D", is a game engine that makes it super easy to build ...

My Software Job Transition Strategies?

I’ve been spending a good deal of the last two days preparing mentally for starting a whole new challenge as a developer. New things aren’t new to me, but this is different and big enough really call for some Deep Thoughts ™. For one thing, I’ve made a big move from the world of Python web development to totally other Python work and while web development has never been the only thing I do, it has been the only work that paid the bills. That transition isn’t one that bothers me or daunts me, though. Instead, I’m thinking about transitioning to the scope of the work I’m getting into. For a long time, I juggled multiple clients and client projects every day, so no single project usually took up most of my time. Every developer juggles time through the day, but exactly how that works in each company and on each project varies a lot. I was looking for a place that I could really focus in a way that I haven’t for a long time. I think I found that, but now I have to deal with the consequen...