带回调的Javascript对象方法中的递归

Question

I have a challenge with recursion within a javascript object method that I am hoping someone can help with. It may require some re-factoring of my code.

I am creating a number of objects of the same type using an object factory - To keep things simple, let's assume the object has following properties;

this.objID;
this.dependents      = []; //array of objects linked to this one
this.otherProperty   = "";
this.anotherProperty = "";

Now consider the following code:

MyObject.prototype.updateDependents = function() {
    doStuff(this);
    this.getDependents(doStuff);
};


MyObject.prototype.getDependents = function(callback,callback_opts) {
    var deps = [];
    if (typeOf callback !== "function") { callback = false; }
    for (var i = 0; i < this.dependents.length; i++) {
        deps.push(this.dependents[i]);
        if (callback) {
            callback(this.dependents[i],callback_opts);
        }
    }
    return deps;
};

function doStuff(myObj) {
    //..do some stuff to "myObj" (i.e. update other properties)
};

I am calling the method 'updateDependents' on an object and then want to get all the other objects that are dependents of that object (as stored in the 'dependents' property) and apply the function 'doStuff' to those dependent objects. This bit works fine.

The bit I am struggling with is how to then call the getDependents method recursively on the objects that are dependents of the first object and apply the same callback function, and then do the same on any further levels of dependent objects, etc (ie multiple, and unknown levels of dependency).

Any suggestions on the best way to do this???

Answer 1

You would simply call it on each of the dependents you are traversing:

for (var i = 0; i < this.dependents.length; i++) {
    deps.push(this.dependents[i]);
    deps.push.apply(deps, this.dependents[i].getDependents(callback,callback_opts));
    …

The order in which you call this (vs. when you push the single dependent and call the callback on it) determines the traversal order . Use what you need or like.