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ChrisMoney/extendjs.js

Created April 6, 2016 19:02
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ExtendJS code
Raw
extendjs.js
<head>
<script src="http://cdn.extendjs.org/0.2.3/extend.min.js"></script>
...
</head>
//Create MyClass by extending Class.
var MyClass = Class.extend(function(){
//Classes can have constructors
this.constructor = function(){
//...
};
});
//---------Working with methods
var MyClass = Class.extend(function(){
//This is a private method.
function privateMethod(){
console.log("Private method executed");
}
//this is a public method.
this.publicMethod = function(){
console.log("Public method executed");
};
this.constructor = function(){
//Private methods accessed inside the class instances.
privateMethod();
};
});
//Public variables can be accessed as properties on class instances.
var instance = new MyClass();
instance.publicMethod();
//Outputs
//=> "Private method executed";
//=> "Public method executed";
console.log(new MyClass() instanceof MyClass); //=> "true"
//Working with variables
var MyClass = Class.extend(function(){
//This is a private variable.
var privateVariable = "private variable";
//this is a public variable.
this.publicVariable = "public variable";
this.constructor = function(){
//Private variables can only be accessed inside the class instances.
console.log(privateVariable); //=> "private variable";
};
});
//Public variables can be accessed as properties on class instances.
var instance = new MyClass();
console.log(instance.publicVariable); //=> "public variable"
//---------Extending your own classes
//Define MyClass
var MyClass = Class.extend(function(){
//Declare public variable
this.variable = "public variable";
});
//MyOtherClass extends MyClass
var MyOtherClass = MyClass.extend(function(){
});
//----------The super constructor
//Define MyClass
var MyClass = Class.extend(function(){
this.constructor = function(){
//Output from original class constructor
console.log("MyClass constructor");
};
});
//MyOtherClass extends MyClass
var MyOtherClass = MyClass.extend(function(){
this.constructor = function(){
//Execute the constructor of the class we extended.
this.super();
//Output from extending class
console.log("MyOtherClass constructor");
};
});
//Create instance of MyOtherClass
var instance1 = new MyOtherClass();
//Outputs
//=> "MyClass constructor"
//=> "MyOtherClass constructor"
var instance = new MyOtherClass();
console.log(instance.variable); //=> "public variable"
//-----------Method overloading
//Define MyClass
var MyClass = Class.extend(function(){
//Decleare test method
this.testMethod = function(){
console.log("MyClass test method");
};
});
//MyOtherClass extends MyClass
var MyOtherClass = MyClass.extend(function(){
//Overload test method
this.testMethod = function(){
//Calling super instance of testMethod
this.super.testMethod();
console.log("MyOtherClass test method");
};
});
//Create instance of MyOtherClass
var instance = new MyOtherClass();
//Call test method.
instance.testMethod();
//Outputs
//=> "MyClass test method"
//=> "MyOtherClass test method"
//Advanced: Scope guarantee
//Define MyClass
var MyClass = Class.extend(function(){
//Decleare test method
this.testMethod = function(){
console.log(
"MyClass test method",
this instanceof MyClass
);
};
});
//Create instance of MyClass
var instance = new MyClass();
//Call method of class such that scope would normally be global.
setTimeout(instance.testMethod,100);
//Output after 100ms
//=> "MyClass test method", true
//----------Advanced: The initializer method
var MyClass = Class.extend(function(){
//initializer is executed before the constructor.
this.initializer = function(){
//...
};
});
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