Using namespacing with object literal notation and inheritance

问题

I am using name-spacing with object literal notation. I would like to use prototype object inheritance so that Scene is "subclass" of Snippet.

I am not able to initiate Scene object properly.

console.log(scen1 instanceof xxx.prototypes.Scene); // false

Basically Scene object should have all properties and methods from Scene + from Snippet and the result should be:

console.log(scen1 instanceof xxx.prototypes.Scene); // true

Any idea what I am doing wrong here?

;
(function(xxx, window) {
    xxx.prototypes = {
        Snippet: function(snippetId) {
            var parent = this;
            this.id = snippetId;
            this.data;
            this.isVisible = 'test';
            this.isFocused = false;
            this.focus = function() {};
            this.render = function() {};
        },
        Scene: function(scenaId) {
            xxx.prototypes.Snippet.call(this);
            xxx.prototypes.Scene.prototype = Object.create(xxx.prototypes.Snippet.prototype);
            xxx.prototypes.Scene.prototype.constructor = xxx.prototypes.Snippet;
            xxx.prototypes.Scene.prototype.isScene = true;
            xxx.prototypes.Scene.prototype.isActive;
        }
    };
}(window.xxx= window.xxx|| {}, window));

//-----------------------------------------------------
function start() {
    var snip1 = new xxx.prototypes.Snippet('snip1');
    snip1.data = 'snippet-data-1';
    snip1.focus();

    var scen1 = new xxx.prototypes.Scene('scen1');
    scen1.data = 'scene-data-1';
    scen1.focus();      

    console.log(snip1 instanceof xxx.prototypes.Snippet); // TRUE
    console.log(scen1 instanceof xxx.prototypes.Scene); // FALSE PROBLEM HERE
}

Answer

(function(xxx, window) {
    xxx.prototypes = {
        Snippet: function(snippetId) {
            var parent = this;
            this.id = snippetId;
            this.data;
            this.isVisible = 'test';
            this.isFocused = false;
            this.focus = function() {};
            this.render = function() {};
        },
        Scene: function(scenaId) {
            xxx.prototypes.Snippet.call(this, scenaId);
            this.isScene = true;
            xxx.prototypes.Scene.prototype.isActive;
        }
    };
}(window.xxx= window.xxx|| {}, window));



//-----------------------------------------------------
function start() {
    var snip1 = new xxx.prototypes.Snippet('snip1');
    snip1.data = 'snippet-data-1';
    snip1.focus();


    var scen1 = new xxx.prototypes.Scene('scen1');
    scen1.data = 'scene-data-1';
    scen1.focus();


    console.log(snip1 instanceof xxx.prototypes.Snippet); // TRUE
    console.log(scen1 instanceof xxx.prototypes.Scene); // TRUE
    console.log(scen1);
}
start();

回答1:

you changed prototype of Scene here:

xxx.prototypes.Scene.prototype = Object.create(xxx.prototypes.Snippet.prototype);

check this article about Object.create

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/create

edited -- >

   Scene: function(scenaId) {
            xxx.prototypes.Snippet.call(this, scenaId);
            this.isScene = true;
            xxx.prototypes.Scene.prototype.isActive;
   }

来源：https://stackoverflow.com/questions/19677089/using-namespacing-with-object-literal-notation-and-inheritance

标签

javascript

javascript-objects