CODEWITHSUNDEEP
javascriptinheritance
Austin Davis
Austin Davis

Reputation: 3756

How to inherit methods from a parameter in your classes constructor

So I'm exporting an object from one file and I'm trying to inherit all of it's methods and add

function childClass (model) { 
this.model = model
}

childClass.prototype.foo1 = function(){
this.model.Something1();
}

childClass.prototype.foo2 = function(){
this.model.Something2();

}

Ideally when someone instantiates an object from childClass I would like for it to inherit all of the methods from the base model object the class is using, just so that instead of calling obj.model.function1 I could just call obj.function1.

Upvotes: 0

Views: 36

Answers (2)

Sean
Sean

Reputation: 3042

you are actually ask how to mix the model in childclass

function childClass (model) { 
 Object.keys(model).forEach(function(key) {
   childClass.prototype[key] = model[key].bind(model);
 });
}

var m = { create: function() {console.log(this);}};

var c = new childClass(m);
c.create();

the this context of the create method will be model, if you don't want to bind this to model, than remove bind function

Upvotes: 0

user663031
user663031

Reputation:

You may be looking for a delegation pattern, which you could implement as:

defineDelegate(delegatee, method) {
    childClass.prototype[method] = function() {
        var delegatee = this[delegatee];
        return delegatee[method].apply(delegatee, arguments);
    };
}

Now you can say

defineDelegate('model', 'Something1');
defineDelegate('model', 'Something2');

This will need to be cleaned up and generalized, but I hope you get the idea.

If for some reason you want to delegate all methods on model:

Object.keys(modelClassPrototype)
    .filter (function(k) { return typeof modelClassPrototype[k] === 'function'; })
    .forEach(function(k) { defineDelegate('model', k); })
;

Upvotes: 1

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