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Revision: 45407
at April 30, 2011 15:38 by anagai
Updated Code 
<?php
?>
<html>
<head>
<style>

</style>

</head>
<body>

<script>
//Contain all in anonymous self executing func to create namespace
//Create object instances and assign to window global object
//Always execute copyPrototype() right after class constructor and before defining prototype functions.
//Ref: http://blogs.sitepoint.com/javascript-inheritance/
(function (win) {
	
var my = {};

function rtrim(val) {
	return val.replace(/\s+$/,"");
}


//private method
function copyPrototype(descendant, parent) {
  

	var sConstructor = parent.toString();  
	var aMatch = sConstructor.match( /\s*function (.*)\(/ );
	//fix ie 6 problem if their is trailing space after func name then trim it
	aMatch[1] = rtrim(aMatch[1]); 
	if ( aMatch != null ) { descendant.prototype[aMatch[1]] = parent; }  
	for (var m in parent.prototype) {  
      descendant.prototype[m] = parent.prototype[m];  
     }  
    //console.log(descendant.prototype);
};

function Animal () {
    this.species = "animal";
}

Animal.prototype.category = function() {
    alert(this.species);
};

Animal.prototype.contest = function() {
    alert('Animal contest');
};

function Dog() {

	//Calling parent constructor
    this.Animal();
    this.species += ":dog";

}
// Dog "inherits" from Animal
copyPrototype(Dog, Animal);

function Poodle() {
    this.Dog();
    this.species += ":poodle";

}


// Poodle "inherits" from Dog
copyPrototype(Poodle, Dog);

Poodle.prototype.contest = function() {
    alert('Poodle contest');
};

//public instances
my.Dog = new Dog();
my.Poodle = new Poodle();

//Create closure. assign to window object to make available to global space
win.$Noah = my;

}(window));
	
//****** Single inheritance. 
//displays animal:dog. 
$Noah.Dog.category();

//******  multiple inheritance
//displays animal:dog:poodle
$Noah.Poodle.category();

//****** Child with multiple parents
//Dog inherits from both Animal and Quadruped classes
//copyPrototype(Dog, Animal);
//copyPrototype(Dog, Quadruped);  

//****** method overriding

//Executes super class contest()
//Displays 'Animal Contest'
$Noah.Dog.contest();

//Executes overriden contest() in Poodle class
//Displays 'Poodle Contest'
$Noah.Poodle.contest();



</script>
</body>
</html>

Revision: 45406
at April 29, 2011 16:19 by anagai
Initial Code 
<?php
?>
<html>
<head>
<style>

</style>

</head>
<body>

<script>
//Contain all in anonymous self executing func to create namespace
//Create object instances and assign to window global object
(function (win) {
	
var my = {};

//private method
function copyPrototype(descendant, parent) {
	
    var sConstructor = parent.toString();
    //****** Added className property to avoid doing regex match below
    //var aMatch = sConstructor.match( /\s*function (.*)\(/ );
    //if ( aMatch != null ) { descendant.prototype[aMatch[1]] = parent; }
    
    descendant.prototype[parent.prototype.className] = parent;
    for (var m in parent.prototype) {
        if(m!=='className') descendant.prototype[m] = parent.prototype[m];
    }
    //console.log(descendant.prototype);
};

function Animal() {
    this.species = "animal";
}

Animal.prototype.className = 'Animal';
Animal.prototype.category = function() {
    alert(this.species);
};

function Dog() {
    this.Animal();
    this.species += ":dog";
	var className = 'Dog';
}

Dog.prototype.className = 'Dog';
// Dog "inherits" from Animal
copyPrototype(Dog, Animal);
function Poodle() {
    this.Dog();
    this.species += ":poodle";
    var className = 'Poodle';
}

Poodle.prototype.className = 'Poodle';
// Poodle "inherits" from Dog
copyPrototype(Poodle, Dog);

//public instances
my.Dog = new Dog();
my.Poodle = new Poodle();

//Create closure. assign to window object to make available to global space
win.$Noah = my;

}(window));

$Noah.Dog.category();
//displays animal:dog
$Noah.Poodle.category();
//displays animal:dog:poodle


</script>
</body>
</html>
Initial URL 

                                

                                                            

                                    

                                        

                                        Initial Description
                                        

                                    

                                    

                                

                                                            

                                    

                                        

                                        Initial Title
                                        

                                    

                                    
Proper Classical Inheritence in Javascript

                                

                                                            

                                    

                                        

                                        Initial Tags
                                        

                                    

                                    

                                

                                                            

                                    

                                        

                                        Initial Language
                                        

                                    

                                    
JavaScript