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POJavascript class extension : calling base class-function from child-class function : seem to be calling static method
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  1. POJavascript class extension : calling base class-function from child-class function : seem to be calling static method
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    copied!<p>This is complicated to explain but I've been on this for days now. I'm "extending" one Javascript "class" to another but calling a base-class method from a child-class method does not work properly. It seems as if the base-class-method "acts" as a static method : properties that are defined in the childclass somehow have their default values when calling a base-class-method from a-child-class method. </p> <p>To keeps things simple I didn't include my elaborate code but created a simple example of what I'm doing:</p> <pre><code>function extend(Child, Parent){ var F = function(){}; F.prototype = Parent.prototype; Child.prototype = new F(); Child.prototype.constructor = Child; Child.base = Parent.prototype; } function BaseClass(){ } BaseClass.prototype.randomNumber = 0; BaseClass.prototype.functionA = function(){ this.randomNumber = 200; this.functionB(); } BaseClass.prototype.functionB = function(){ alert(this.randomNumber); console.info(this); } function ChildClass(){ this.functionB = function(){ ChildClass.base.functionB(); }; } extend(ChildClass, BaseClass); var childInstance = new ChildClass(); childInstance.functionA(); </code></pre> <p>I'm using firebug to log to the console. It output's "Baseclass" and this.randomNumber is somehow 0 while it is set to 200 in functionA.</p> <p>the extend-method I'm using is simular to the one from Yahoo.lang.extend which I also tried with the same result.</p> <p>I can't figure out if I'm missing something or this is just one of the drawbacks from "extending" Javascript and I'm actually calling a "static" method here. Help would be much appreciated here. Hope it's clear what I'm trying to do here because I find it complicated to put it in words. Thanks a lot in advance!</p>
 

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