@jtq/object-walker

Object Walker

Simple object walker with a per-value callback.

Basic example

Walk an object tree and spit out all simple values and their paths.

var walker = require('object-walker');

var obj = {
	a: 0,
	b: 0xFF0000,
	c: -10.1,
	d: {
		a: 10
	}
};

walker.walk(obj, function(val, path) {
  console.log(path, val);
});

More complex example: tweening system

Define an original object with properties and a target object with target values for some or all of the original object's properties. Then define a "tweening" function that will calculate the values of the object at any arbitrary point along the spectrum from original to target.

var walker = require('object-walker');

var from = {
	top: 10,
	left: 25,
	scale: 1,
	rotation: 0
};

var to = {
	top: 100,
	left: 0,
	scale: 1.5,
	rotation: 90
};

// Given a "from" object, a "to" object and a "progress" parameter (0 -> 1), calculate the values of the "from" object's properties at that point
function tween(from, to, progress) {

	var result = JSON.parse(JSON.stringify(from));	// Quick hacky object deep-clone

	walker.walk(from, function(val, path) {
		var diff = walker.get(to, path) - walker.get(from, path);
		var newval = walker.get(from, path) + (diff * progress);
		walker.set(result, path, newval);
	});

	return result;
}

console.log("start", from);
for(var i=1; i<=10; i++) {
	console.log(i, tween(from, to, i/10));
}