Click here to Skip to main content
6,822,123 members and growing! (17,642 online)
Email Password   helpLost your password?
General Programming » Programming Tips » General     Intermediate License: The Code Project Open License (CPOL)

Object Oriented JavaScript Class Library in C#/.NET Style

By EJocys

JavaScript classes ported from .NET
Javascript, CSS, HTML, .NET (.NET1.0, .NET1.1, .NET2.0, Mono, DotGNU, .NET3.0, .NET3.5), ASP, ASP.NET, Ajax
Revision:15 (See All)
Posted:12 Dec 2007
Updated:21 Jun 2009
Views:83,688
Bookmarked:165 times
printPrint   add Share
      Discuss Discuss   Broken Article?Report  
68 votes for this article.
Popularity: 8.66 Rating: 4.73 out of 5
2 votes, 2.9%
1
1 vote, 1.5%
2

3
2 votes, 2.9%
4
63 votes, 92.6%
5

Introduction  

Welcome to Object Oriented JavaScript class library in C#/.NET style.

Background  

I like coding with JavaScript in object oriented style. But one day, I decided to bring my code into another level and make my JavaScript code to look like C# as much as possible. So I did the following:

  1. Started to use .NET coding standards on my JavaScripts. You can find them on MSDN - .NET Framework General Reference: Naming Guidelines.
  2. Ported some basic useful classes and methods from .NET to JavaScript with the same class and property names. Some code parts were written from scratch, some parts were borrowed from the Internet and some parts were ported from C# directly.
  3. Started to use XML Comments inside JavaScript. They are not supported very well by Visual Studio 2008 but I hope support will be better in the future.
http://www.jocys.com/Common/JsClasses/Documents:

Screenshot - JocysComClassBrowser.jpg

Example: HMAC-MD5 Checksum

C# (3.0) code to create HMAC-MD5 checksum:

// Create HMAC-MD5 Algorithm.
var hmac = new System.Security.Cryptography.HMACMD5();  
// Convert string to array of bytes.
var key = System.Text.Encoding.UTF8.GetBytes("test key");  
var data = System.Text.Encoding.UTF8.GetBytes("test data");  
// Compute hash.  
var hashBytes = hmac.ComputeHash(key, data);
// Convert to HEX string.
var hex = System.BitConverter.ToString(hashBytes);
// Convert to GUID so you can store it inside database.
var guid = new System.Guid(hashBytes);

HMAC-MD5 checksum code written with this JavaScript library:

Include JavaScripts:

  • System.js
  • System.BitConverter.js
  • System.Text.js
  • System.Security.Cryptography.MD5.js
  • System.Security.Cryptography.HMACMD5.js
// Create HMAC-MD5 Algorithm.
var hmac = new System.Security.Cryptography.HMACMD5();  
// Convert string to array of bytes.
var key = System.Text.Encoding.UTF8.GetBytes("test key");  
var data = System.Text.Encoding.UTF8.GetBytes("test data");  
// Compute hash.  
var hashBytes = hmac.ComputeHash(key, data);
// Convert to HEX string.
var hex = System.BitConverter.ToString(hashBytes);
// Convert to GUID so you can store it inside database.
var guid = new System.Guid(hashBytes);

As you can see, the code is 100% identical.

Example: AES-256 Encryption

C# (3.0) code for AES-256 encryption:

// Turn input string into a byte array.
var input = System.Text.Encoding.Unicode.GetBytes("Plain Text");
// Create an instance of the Rijndael class.
var cipher = new System.Security.Cryptography.RijndaelManaged();
// Calculate salt to make it harder to guess key by using a dictionary attack.
var password = System.Text.Encoding.UTF8.GetBytes("password");
var hmac = new System.Security.Cryptography.HMACSHA1(password);
var salt = hmac.ComputeHash(password);
// Generate Secret Key from the password and salt.
// Note: Set number of iterations to 10 in order for JavaScript example to work faster.
var secretKey = new System.Security.Cryptography.Rfc2898DeriveBytes(password, salt, 10);
// Create a encryptor from the existing SecretKey bytes by using
// 32 bytes (256 bits) for the secret key and
// 16 bytes (128 bits) for the initialization vector (IV).
var key = secretKey.GetBytes(32);
var iv = secretKey.GetBytes(16);
// Get cryptor as System.Security.Cryptography.ICryptoTransform class.
var cryptor = cipher.CreateEncryptor(key, iv);
// Create new Input.
var inputBuffer = new byte[input.Length];
// Copy data bytes to input buffer.
System.Buffer.BlockCopy(input, 0, inputBuffer, 0, inputBuffer.Length);
// Create a MemoryStream to hold the output bytes.
var stream = new System.IO.MemoryStream();
// Create a CryptoStream through which we are going to be processing our data.
var mode = System.Security.Cryptography.CryptoStreamMode.Write;
var cryptoStream = new System.Security.Cryptography.CryptoStream(stream, cryptor, mode);
// Start the crypting process.
cryptoStream.Write(inputBuffer, 0, inputBuffer.Length);
// Finish crypting.
cryptoStream.FlushFinalBlock();
// Convert data from a memoryStream into a byte array.
var outputBuffer = stream.ToArray();
// Close both streams.
stream.Close();
cryptoStream.Close();
// Convert encrypted data into a base64-encoded string.
var base64String = System.Convert.ToBase64String(outputBuffer);
// base64String = laFf3eKu9tzB2XksJjd8EVM3PA9O30wz0Y+X3nyelW4=

Same AES-256 encryption code written with this JavaScript library:

Include JavaScripts:

  • System.js
  • System.IO.js
  • System.Text.js
  • System.Convert.js
  • System.BitConverter.js
  • System.Security.Cryptography.js
  • System.Security.Cryptography.SHA1.js
  • System.Security.Cryptography.HMACSHA1.js
  • System.Security.Cryptography.RijndaelManaged.js
// Turn input string into a byte array.
var input = System.Text.Encoding.Unicode.GetBytes("Plain Text");
// Create an instance of the Rijndael class.
var cipher = new System.Security.Cryptography.RijndaelManaged();
// Calculate salt to make it harder to guess key by using a dictionary attack.
var password = System.Text.Encoding.UTF8.GetBytes("password");
var hmac = new System.Security.Cryptography.HMACSHA1(password);
var salt = hmac.ComputeHash(passwordBytes);
// Generate Secret Key from the password and salt.
// Note: Set number of iterations to 10 in order for JavaScript example to work faster.
var secretKey = new System.Security.Cryptography.Rfc2898DeriveBytes(password, salt, 10);
// Create a encryptor from the existing SecretKey bytes by using
// 32 bytes (256 bits) for the secret key and
// 16 bytes (128 bits) for the initialization vector (IV).
var key = secretKey.GetBytes(32);
var iv = secretKey.GetBytes(16);
// Get cryptor as System.Security.Cryptography.ICryptoTransform class.
var cryptor = cipher.CreateEncryptor(key, iv);
// Create new Input.
var inputBuffer = new System.Byte(input.length);
// Copy data bytes to input buffer.
System.Buffer.BlockCopy(input, 0, inputBuffer, 0, inputBuffer.length);
// Create a MemoryStream to hold the output bytes.
var stream = new System.IO.MemoryStream();
// Create a CryptoStream through which we are going to be processing our data.
var mode = System.Security.Cryptography.CryptoStreamMode.Write;
var cryptoStream = new System.Security.Cryptography.CryptoStream(stream, cryptor, mode);
// Start the crypting process.
cryptoStream.Write(inputBuffer, 0, inputBuffer.length);
// Finish crypting.
cryptoStream.FlushFinalBlock();
// Convert data from a memoryStream into a byte array.
var outputBuffer = stream.ToArray();
// Close both streams.
stream.Close();
cryptoStream.Close();
// Convert encrypted data into a base64-encoded string.
var base64String = System.Convert.ToBase64String(outputBuffer);
// base64String = laFf3eKu9tzB2XksJjd8EVM3PA9O30wz0Y+X3nyelW4=

There is one difference. In JavaScript, I need to use "new System.Byte(length)" instead of simple "new byte[length]" with square brackets. Of course, I can create a class alias by doing "byte = System.Byte" inside JavaScript and make that difference smaller.

Example: User Interface

function firstButton_Click(){
    Trace.Write("First Button Click");
}

function secondButton_Click(){
    Trace.Write("Second Button Click");
}

function Window_Load(){
    Trace.IsEnabled = true;
    Trace.Write("Start Demo");
    // Create toolbar.
    var toolBar = new System.Web.UI.Interface.ToolBar("MyToolBar");
    // Add toolbar to document.
    document.body.appendChild(toolBar.Node);
    // Create Bar.
    var bar = new System.Web.UI.Interface.Bar("MainBar", document, "Bar Title");
    toolBar.Add(bar);
    // Create first button.
    var firstButton = new System.Web.UI.Interface.Button("FirstButton", document);
    firstButton.SetText("First");
    firstButton.SetImage("Images/Icons/Options-16x16.png");
    firstButton.SetTitle("First Button");
    firstButton.customAction = firstButton_Click;
    bar.Add(firstButton);    
    // Create second button.
    var secondButton = new System.Web.UI.Interface.Button("SecondButton", document);
    secondButton.SetText("Second");
    secondButton.SetImage("Images/Icons/Trace.16x16.png");
    secondButton.SetTitle("Second Button");
    secondButton.customAction = secondButton_Click;
    bar.Add(secondButton);    
}

window.onload = Window_Load;

Will produce this interface on the web page:

JocysComJavaScriptClassesToolBar.png

Benefits

Coding with JavaScript in C# .NET style provides these benefits:

  1. Any C# developer instantly understands the purpose of JavaScript code.
  2. You don't need to write help for your new JavaScript classes because Microsoft did it already.
  3. When porting a new class from C# to JavaScript, you don't need to think about how to name it or where to put it. All you need is to look for the same class in C# and use the same naming.
  4. More JavaScript classes you have, the easier it will be to port new ones.
  5. By using C# classes as primary reference, it will be much easier for different developers to write and integrate JavaScript classes into one big file library. It is because by looking at some C# class, the developer knows what type of input and output function must support/produce and he doesn't need to coordinate this with other developers.
  6. And many more...

Requirements

JavaScript has a very limited number of types:

JavaScript Object typeof(Object)
Object 'object'
Array 'object'
Function 'function'
String 'string'
Number 'number'
Boolean 'boolean'
null 'object'
undefined 'undefined'

But by combining the existing types, we can create JavaScript objects similar to C#. For example:

C# Type JavaScript Type
public property declared with "this." prefix: this.Name = new String;
private property declared with "var" prefix: var name = new String;
class this.[ClassName] = function(){... without "return value;" at the end
void function which has no "return value;" at the end
short/Int16 whole Number from [-2^15, 2^15-1] range
int/Int32 whole Number from [-2^31, 2^31-1] range
long/Int64 whole Number from [-2^63, 2^63-1] range (Requires BigInteger class)
byte whole Number from [0, 255] range: var b = 14;
sbyte whole Number from [-128, 127] range: var sb = -14;
bytes[] Array() filled with integers from [0-255] range.
bit Number: 0 or 1
bit[] Array() filled with integers from [0-1] range.
char String which contains a single character. Declared with single quotes: var c = 's'
char[] Array() filled single characters:
var chars = new Array(1); chars[0] = 's';
object parameter which was declared with "{ }": var o = {};
enum Object with "Enum" sufix and comma separated values: this.TriStateEnum = { Unknown: -2, False: 0, True: 1 }
EventHandler function with parameters "sender" and "e": function(sender, e) or this.Click(sender, e)

NUMBERS: All numbers in JavaScript are 64-bit (8 bytes) floating point numbers (double: 1-bit sign, 11-bits exponent, 52-bits mantissa). There is no Double, Single/Float, Boolean, Int16, UInt16, Int32 or UInt32. But you can use public static methods of System.BitConverter JavaScript class in order to treat the same JavaScript number as a different type:

// Convert number to [0x00, 0x00, 0xCC, 0xCC] array.
var bytes = System.BitConverter.GetBytes(-859045888, System.TypeCode.Int32);
// Convert bytes back to -859045888.
var n = System.BitConverter.ToInt32(bytes, 0);  
System.BitConverter JavaScript class supports little-endian (default), big-endian byte orders and numeric arrays. System.BitConverter class is very useful in encoding/decoding/encryption/decryption classes. Please note that you need to specify number type when using GetBytes(value, typeCode) method by using System.TypeCode enumeration values (this enumeration is located inside System.js file).

I've added System.BigInt class (same as .NET internal System.Security.Cryptography.BigInt class). It represents an arbitrarily large signed integer whose value in theory has no upper or lower bounds. It means you can add, subtract, multiply, divide numbers of Godzilla proportions in JavaScript which can be useful with client side encryption: 

// Increase global System.BigInt size to 512 bytes.
// BigInt will act like System.Int4096 (default is System.Int1024).
System.BigInt.MaxBytes = 512;
// Create big integer from hexadecimal number.
var n1 = new System.BigInt("0x010203040506");
// Create big integer from decimal number.
var n2 = new System.BigInt("-280422911905295");
// Multiply them.
var n3 = System.BigInt.Multiply(n2, n1);
// Store result in various forms.
var h = n3.ToHex()     // -0x01010C234779B3FAEED09F5A
var d = n3.ToDecimal() // -310751254825142252681076570
var bytes = n3.Elements // A6602F11054C86B8DCF3FEFEFFFFFF...   

NOTE: You can use <param type="byte[]" name="data">...</param> inside JavaScript XML Comments in order to specify type of input data and <returns type="double">...</returns> - for output.

Files from this JavaScript library can be included on the client and server side, thanks to special header and footer:

<!--//--><%
//=============================================================================
// Jocys.com JavaScript.NET Classes (In C# Object Oriented Style)
// Created by Evaldas Jocys <evaldas@jocys.com>
//-----------------------------------------------------------------------------
// You can include this script on both sides - server and client:
// Server: <!-- #INCLUDE FILE="ScriptFile.js" -->
// Client: <script type="text/javascript" src="ScriptFile.js"></script>
//=============================================================================
        
JavaScript Code Here...

//==============================================================================
// END
//------------------------------------------------------------------------------
//%>

... and by avoiding Response.Write() or alert() use directly: for example: I can detect if the script is running on the server side or client side and show the message accordingly with this code:

this.IsServerSide = (typeof(Response) == "object");
// If we are on server side then...
if (this.IsServerSide){
    // Write text to output.
    Response.Write(text);
}else{
    // Show popup message.
    alert(text);
}

JavaScript IntelliSense

Visual Studio 2008 has built-in support for JavaScript IntelliSense. This means that if you open System.BitConverter.js file, place cursor at the end of file and type "System.BitConverter." then straight after the dot, VS 2008 will bring up a menu containing all available methods and properties of System.BitConverter class:

JocysComJavaScriptIntelliSense.gif

The good news here is that Microsoft is moving in the right direction. The bad news is that JavaScript IntelliSense works only with specific JavaScript coding style and sometimes needs workarounds. In other words, it works in mysterious ways or doesn't work at all :). Some extra upgrades are needed on my code I guess.

Installation

Extract source archive into webroot (/) folder of your website.

Example: System.Security.Password

Inside the source code, you can find examples (Examples/) including password generator example. You can run it: 

Screenshot - SystemSecurityPasswordGeneratorGui.gif

To make a suggestion or report bugs, please write to evaldas@jocys.com.

History

  • 2009-06-21 - New System.BigInt(.js file) class with examples:
    • Examples/System.BigInt.htm
    • Examples/System.BigInt.aspx
  • 2009-03-14 - PassGen now works in Internet Explorer again. Some cross-domain security issues with FX fixed. Adjusted to work better with "Microsoft AJAX Framework" scripts (Resource of System.Web.Extensions.dll/MicrosoftAjax.debug.js). Microsoft has some cool JavaScript classes there. 
  • 2009-02-04 - New fixes and new bugs. Moved everything to /Common/JsClasses folder. Latest source available from SVN server (see above). 
  • 2008-03-14 - Some bug fixes:
    • New Classes:
      • System.Web.UI.HtmlControls.TextBox.CommandLine - Converts input to command line. Will be used later to create plain JavaScript console and in chat applications.
    • Examples Updated (Examples/ folder):
      • System.Web.UI.HtmlControls.TextBox.CommandLine.htm
      • System.Web.UI.ShortKeys/System.Web.UI.ShortKeys.htm - Shows how to override and use custom windows keyboard layout on the web page. Can also capture keys and perform non-default custom actions. 
  • 2008-01-27
    • New enumerations:
      • System.TypeCode
    • New classes:
      • System.Collections.BitArray
      • System.BitConverter (System.BitConverter.js) class was updated with methods:
      • System.BitConverter.GetByte(value, typeCode) - get bytes from Double, Single, Boolean, Int16, UInt16, Int32, UInt32. You need to use values of System.TypeCode to specify how JavaScript must treat a number.
        You also can convert byte[] back to numbers by using methods
        • System.BitConverter.ToDouble(bytes, startIndex)
        • System.BitConverter.ToSingle(bytes, startIndex)
        • System.BitConverter.ToBoolean(bytes, startIndex)
        • System.BitConverter.ToInt16(bytes, startIndex)
        • System.BitConverter.ToUInt16(bytes, startIndex)
        • System.BitConverter.ToInt32(bytes, startIndex)
        • System.BitConverter.ToUInt32(bytes, startIndex)
      • Int64 and UInt64 types are not available yet because JavaScript 64-bit (8 bytes) float point numbers have only 52-bit mantissa which means that it is not possible to work with 64-bit whole numbers properly (possible by reusing BigInt class).
    • Updated Examples:
      • System.BitConverter.htm
      • System.BitConverter.aspx
  • 2008-01-13 - Some bugs were fixed and new JavaScript classes were added:
    • System.Security.Cryptography.js file:
      • System.Security.Cryptography.Rfc2898DeriveBytes
      • System.Security.Cryptography.ICryptoTransform
      • System.Security.Cryptography.RNGCryptoServiceProvider
      • System.Security.Cryptography.CryptoStrea
    • System.Security.Cryptography.RijndaelManaged.js file (AES encryption):
      • System.Security.Cryptography.RijndaelManaged
    • System.js file (new methods):
      • System.Buffer.BlockCopy
      • System.Array.Reverse
      • System.Array.Clear
      • System.Array.GetMultiDimensional
      • System.Array.FillMultiDimensiona
    • Examples Created (Examples/ folder):
      • System.Security.Cryptography.AES.htm
      • System.Security.Cryptography.AES.aspx
      • System.Security.Cryptography.htm
      • System.Security.Cryptography.aspx
    • Some interface parts/classes/examples were updated to Office 2007 style:
      • System.Web.UI.Interface.ToolBar.htm
      • System.Web.UI.Interface.TabStrip.htm
    • Methods System.BitConverter static class was updated.
  • 2007-12-15 - New 'System.IO.MemoryStream' class. I will use it later with symmetric encryption algorithms so encryption can be done between two web browser clients without any ActiveX.
    Now you can get byte[] arrays filled with 0 numbers in JavaScript easier:
    var bytes = new System.Byte(10);
    It's the same as 'byte[] bytes = new System.Byte[10];' or 'byte[] bytes = new byte[10];' in C#. You can define multi-dimensional arrays filled with zeroes too:
    var bytes = new System.Byte(16,16); bytes[4][5] = 10;
  • 2007-12-12 - Created. Some links inside examples were fixed. New source code was uploaded. Alex's Code Syntax Highlighter was updated to 1.5.1 version.

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

About the Author

EJocys


Member

Occupation: Web Developer
Location: United Kingdom United Kingdom

Other popular Programming Tips articles:

Article Top
You must Sign In to use this message board.
FAQ FAQ 
 
Layout  Per page   
 Msgs 1 to 22 of 22 (Total in Forum: 22) (Refresh)FirstPrevNext
AnswerHow I would have done it. PinmemberSlingBlade1:28 30 Oct '09  
GeneralRe: How I would have done it. PinmemberEJocys2:47 30 Oct '09  
GeneralRe: How I would have done it. PinmemberSlingBlade20:28 30 Oct '09  
Generaluse of activexobject Pinmemberimneo1:32 2 Jul '09  
GeneralRe: use of activexobject PinmemberEJocys10:14 2 Jul '09  
GeneralIt's awesome. PinmemberMohammad Jahedur Rahman2:19 5 Feb '09  
GeneralGood job Pinmemberjeasonzhao19:33 4 Feb '09  
GeneralCan I use it with Visual Studio.net 2003? PinmemberRandomYang18:29 29 Jan '08  
AnswerRe: Can I use it with Visual Studio.net 2003? [modified] PinmemberEJocys1:05 30 Jan '08  
GeneralRe: Can I use it with Visual Studio.net 2003? PinmemberRandomYang15:26 31 Jan '08  
GeneralReally awesome! But what about the other approach? Pinmemberhartertobak22:38 13 Dec '07  
GeneralRe: Really awesome! But what about the other approach? PinmemberDewey23:08 14 Dec '07  
GeneralRe: Really awesome! But what about the other approach? Pinmemberhartertobak5:49 20 Dec '07  
GeneralRe: Really awesome! But what about the other approach? PinmemberBen Daniel17:35 19 Dec '07  
GeneralWhere's the solution PinmemberDewey14:19 13 Dec '07  
AnswerRe: Where's the solution PinmemberEJocys23:48 13 Dec '07  
GeneralTop work PinmemberBen Daniel16:05 12 Dec '07  
GeneralRe: Top work PinmemberThomas Lykke Petersen21:24 13 Dec '07  
GeneralExcellent Job PinmemberYuancai (Charlie) Ye6:29 12 Dec '07  
GeneralRe: Excellent Job PinmemberKel_12:48 12 Dec '07  
Generalgreat and big job! PinmemberiBDev5:10 12 Dec '07  
Generalvery nice idea! Pinmembertuskilan2:29 12 Dec '07  

General General    News News    Question Question    Answer Answer    Joke Joke    Rant Rant    Admin Admin   

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads.

PermaLink | Privacy | Terms of Use
Last Updated: 21 Jun 2009
Editor: Deeksha Shenoy
Copyright 2007 by EJocys
Everything else Copyright © CodeProject, 1999-2010
Web22 | Advertise on the Code Project