I.js

Extension to JavaScript

Ijs provides developer with extended functionality given to native JavaScript constructors or objects. Ijs extends JavaScript's Object, Function and Array constructors.

Object Extensions

Object.createStateProperty

This Ijs API of Object Extension creates a property in the given object whose runtime value will be determined by the value of another property in the same object. More information at https://github.com/ishaananuraag/StateProperty.js/blob/master/README.md

Syntax:

Object.defineStateProperty(obj[, prop], descriptor);

Parameters

• obj The object on which to define the property.
• prop (or valueAttribute) - The name or Symbol of the property to be defined. (default: 'value')
• descriptors The descriptors for the property being defined.

Descriptors:

• values This is the actual object representing different states(as keys) and their values
• stateAttribute The name or Symbol of the property which will determine the value of the valueAttribute. (default: 'state')
• defaultState This is the default state for the property being defined to refer to. If the stateAttribute is already present in object, this has no effect.

Javascript Example:

	var obj={};
	
	Object.defineStateProperty(obj,'showGreeting',{
		values:{
			'en': function(){
				console.log('Hello');
			},
			'fr': function(){
				console.log('Bonjour');
			},
		},
		stateAttribute: 'language',
		defaultState: 'en',	
	});
	
	obj.showGreeting();
	
	obj.language='fr';
	
	obj.showGreeting();

Output:

> Hello
> Bonjour

Each

This Ijs API of Object Extension iterates through own properties of the object and executes the callback.

Syntax:

Object.each(obj , callback [, thisParam]);

Parameters

• obj The object on which to iterate.
• callback Tje function to be called.
• thisParam The object which is to be sent as this to the callback. Default - the object sent.

Javascript Example:

	var obj={firstName: 'Ishaan', lastName: 'Singh'}

	Object.each(obj,function(key, value){
		console.log('Key : '+key+'\t value : '+value);
	});

Output(After 1 second):

	> Key : firstName	 value : Ishaan
	> Key : lastName	 value : Singh

All

This Ijs API of Object Extension iterates through all properties of the object and executes the callback.

Syntax:

Object.all(obj , callback [, thisParam]);

Parameters

• obj The object on which to iterate.
• callback Tje function to be called.
• thisParam The object which is to be sent as this to the callback. Default - the object sent.

Javascript Example:

	var obj={firstName: 'Ishaan', lastName: 'Singh'}

	Object.all(obj,function(key, value){
		console.log('Key : '+key+'\t value : '+value);
	});

Output(After 1 second):

	> Key : firstName	 value : Ishaan
	> Key : lastName	 value : Singh

Array Extensions

Swap

This Ijs API of Array Extension swaps values at two indexes inside the array on which it is called. This Ijs API can be used to swap values in freshly created array as well as the existing array.

Syntax:

[Array].swap(indexI , indexJ [, preserveOriginal]);

Parameters

• indexI The index of first value.
• indexJ The index of second value which is to be swapped with the first.
• preserveOriginal If sent true, the original array will not be modified. A new array is returned instead.

Javascript Example:

	var arr=[0,1,2,3,4,5,6,7,8]

	arr.swap(3,6);
	> (9) [0, 1, 2, 6, 4, 5, 3, 7, 8]
	
	arr 
	> (9) [0, 1, 2, 6, 4, 5, 3, 7, 8]
	
	arr.swap(0,8,true);
	> (9) [8, 1, 2, 6, 4, 5, 3, 7, 0]
	
	arr
	> (9) [0, 1, 2, 6, 4, 5, 3, 7, 8]

Shuffle

This Ijs API of Array Extension shuffles the values inside the array on which it is called.

Syntax:

[Array].shuffle();

Javascript Example:

	var arr=[0,1,2,3,4,5,6,7,8]

	arr.shuffle();
	> (9) [4, 0, 8, 6, 7, 2, 5, 3, 1]
	
	arr
	> (9) [4, 0, 8, 6, 7, 2, 5, 3, 1]
	
	arr.shuffle();
	> (9) [1, 8, 4, 0, 5, 3, 2, 6, 7]
	
	arr
	> (9) [1, 8, 4, 0, 5, 3, 2, 6, 7]

Function Extensions

Schedule

This Ijs API of Function Extension is used to schedule the function on which it is called. The syntax of this Ijs API is same as call API with an extra time parameter required* at the end.

Syntax:

[Function].schedule(thisParam , arg0, arg1 . . .  , time);

Parameters

• thisParam This reference inside the function.
• ** arg0, arg1 . . .** The arguments being passed to the function separated by comma.
• time The time after which it should be called in milliseconds.

Javascript Example:

	var showGreeting = function(firstName, lastName){
		console.log('Welcome '+firstName+' '+lastName);
	}
	
	showGreeting.schedule(this,'Ishaan','Singh',1000);

Output(After 1 second):

> Welcome Ishaan Singh

ScheduleApply

This Ijs API of Function Extension is apply counterpart to schedule. It will be safe to say call:apply::schedule:scheduleApply.

Syntax:

[Function].scheduleApply(thisParam , [arg0, arg1 . . .]  , time);

Parameters

• thisParam This reference inside the function.
• ** [arg0, arg1 . . .]** The array of the arguments being passed to the function separated by comma.
• time The time after which it should be called in milliseconds.

Javascript Example:

	var showGreeting = function(firstName, lastName){
		console.log('Welcome '+firstName+' '+lastName);
	}
	
	showGreeting.scheduleApply(this,['Ishaan','Singh'],1000);

Output(After 1 second):

> Welcome Ishaan Singh