last changed. 12/01/25

Attached is the current development code base for BYOB4 a.k.a. Snap. It consists of several JavaScript, HTML and text files, and while some of it may be functional most parts will be in flux and subject to frequent, even fundamental modifications. This document lays out a few simple guidelines ensuring that collaborative code contribution works out.


Working with changesets
-----------------------
You'll often want to change or add code in existing JS files. Please don't. Instead use a changeset. The way I always do it myself is to copy the empty

	changeset.js

file and rename it to something like

	JensChangesToMorphic.js

Into this file I write all the functions I want to add to Morphic. If I want to change a function in Morphic.js I copy it to the changeset and edit it there. Then I always validate the changeset with 

	JSLint.com

Please check your code frequently with JSLint! 

For our Snap code set JSLint's settings to:

	assume a browser
	tolerate eval (only for morphic.js)
	tolerate unfiltered for in (only for morphic.js)
	tolerate missing 'use strict' pragma

	[4] indentation
	[75] maximum line length

Although you'll probably not ever going to need either EVAL or FORIN in your changesets anyway.

There are, of course, other tools - like Firebug - that help you debug your code. Feel free to use whichever suits you best, but let's all agree on JSLint's (nitpicky) formatting rules so we get code that's well readable and easily shareable among ourselves.


Testing your code
------------------
(don't worry, I'm not talking about formal UnitTest Suites or other BDSM software fetishes, just about playing with what you're creating while you're doing it)

To test your changesets just add another line in the html stub file with your changeset. Make sure to put your changeset /after/ Morphic.js and Blocks.js and whichever libraries are already included, so it'll actually get used.

In your changeset override the world's 

	customMorphs

function so it returns a list of instances of your Morphs. For "Blocks.js" that code is:

	var BlockMorph;
	var ScriptsMorph;

	WorldMorph.prototype.customMorphs = function () {
		var sm = new ScriptsMorph();
		sm.setExtent(new Point(800, 600));
		return [
			new BlockMorph(),
			sm
		];
	};

Just modify this code so it returns your list of sample Morphs instead of BlockMorph and ScriptsMorph instances.

Once you've added this code to your changeset you can open your sample html file in your browser, and you'll find your sample Morphs in the World's DEMO menu.


Inspectors
----------
To actually test play with your Morphs you can right-click on them and open an inspector on them. You can open more than one inspector on each object. The inspector pretty much works the same as in Smalltalk. It even has an evaluation pane at the bottom, in which you can type in any JS code, mark it with your mouse (or select all with ctrl-a), righ-click on the selection and either "do it", "show it" or "inspect it" (again, like in Squeak).

Needless to say, in the evaluation pane "this" always refers to the inspected object.


Source Code Mgmt
-----------------
The good thing about changesets is that you can continue working on them regardless of new dev releases that happen in the meantime. When you feel you've got something that's finished just send me your changeset, and I'll work all the changesets into the Snap codebase and release another dev version. That way there will always (and frequently) be a harmonized common code base. 

Thanks!

--Jens