Intro to JavaScript

function.prototype:

first you define a function. as you do it an empty your_function.prototype object is created like “{}”.
later when you use same function to create a new object using the new operator.
every thing that is in .prototype overrides the function properties and assigned to the newly created object as in inherited functions.

this:

usually the current this variable is referenced to the last object created with “new”
when going into a sub function this resets to this variable of the module (this of the script file)
when you do var x={} it means var x= new Object();
when you do var x=[] it means var x= new Array(); // notice you create object with new operator

change this to the most global this

technique of “loosing” this to – wrap some code inside an anonymous function:

function server() {
 function test(){  
 /// this. // this *this* is of server funvction object
 (function(){ this. })() // wrapper function - this is the trick.  // that *this* is of module 
 }
}

it also creates a new variable scope.
more on that: http://www.adequatelygood.com/2010/2/JavaScript-Scoping-and-Hoisting

techniqe of saving this:

you see here callback inside a callback. a privet variable passed by reference.

function server() {
   function add( data , callback )  {
     var that=this;
     that.beforeadd( data , function (){ 
      that.doadd( data , function (){ 
       that.afteradd( data , function (){ 
        if(callback)callback(); } ); } ); } );
    }}

to publish avariable you do:

var x;
this.x=x; // now x is is public 

to change the this object you call:

func.call(new_this,arg1,arg2) or func.apply(new_this,[arg1,arg2])
in general it allows to call a function as it was a function of an object.

to see current variables in current this object you can call:

sys.puts('this of palce1 ');for( x in this) sys.puts(x); sys.puts('/this of palce1 ');

to make async code you just use callback at the end, as the add function above. and or add it as an event as in picard below

some links:

http://helephant.com/2008/08/how-javascript-objects-work/

http://github.com/dantebronto/picard – see async example to learn what is async. async usualy is only about not blocking when transferring data

http://www.robertsosinski.com/2009/04/28/binding-scope-in-javascript/ – - .apply() and .call()

http://www.packtpub.com/article/using-prototype-property-in-javascript — prototype

http://mckoss.com/jscript/object.htm – - oop in javascript
http://ajax.org – - a real oop javascript framework you can learn more from it about objects and exported functions