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New Comment on "Exposing Javascript functions to the CLR"

CarbonMan — Mon, 10 Dec 2012 10:47:20 GMT

@artyprog I think you are looking at this from the wrong view. All that code is meant to run AS Javascript. The {..} is interpreted by the Jint engine which converts it to <..> I was also confused with it. The problem with the example is that it does not show the code assigned to a string and passed to the Jint engine.

New Comment on "Exposing Javascript functions to the CLR"

artyprog — Mon, 06 Feb 2012 08:47:36 GMT

Idem: list = list.ConvertAll<System.Double>( function (x) { return x * x; });

New Comment on "Exposing Javascript functions to the CLR"

artyprog — Mon, 06 Feb 2012 08:46:37 GMT

A little typo :-) var list = new System.Collections.Generic.List<System.Int32>(); Regards

New Comment on "Passing external functions to scripts"

zhihongwang — Wed, 27 Jul 2011 19:48:18 GMT

You have to call jintEngine.AddPermission(new System.Security.Permissions.UIPermission(System.Security.Permissions.UIPermissionWindow.SafeTopLevelWindows)); Or else simply call jintEngine.DisableSecurity();

Updated Wiki: Debugging

sebastienros — Tue, 19 Jul 2011 00:50:50 GMT

Debugging

Defining debug mode

By default, scripts are executed in Release mode and are not impacted by any debugging overhead. To enable debugging in Jint, the DebugMode property must be set to true.

JintEngine engine = new JintEngine();
engine.SetDebugMode(true);

Debug information

Every debugging feature gives access to some information represented by the class Jint.Debugger.DebugInformation. This class gives access to:

The executed statement
The call stack
The local variables

Executing step by step

The debugger enables to execute the scripts step by step. It exposes an event named Step which is called when any statement is executed. It returns the engine as the sender argument, and a DebugInformation instance. The example below demonstrates how to trace all the executed statements to the console.

JintEngine jint = new JintEngine();
jint.SetDebugMode(true);

jint.Step += (sender, info) =>
{
   Console.WriteLine("{0}: Line {1}, Char {2}", info.CurrentStatement.ToString(), info.Location.Start.Line, info.Location.Start.Char);
};

Evaluating local variables

In the debug information, the local variables are accessible through a dictionary indexed by their names.

Setting breakpoints

Breakpoints are added to the BreakPoints collection of the engine. The class Jint.Debugger.BreakPoint is used to represent a located point in a script string, and optionally define a condition to break the execution.

The example below demonstrates how to stop on a statement inside a function, only if a parameter as a specific value.

JintEngine jint = new JintEngine();
jint.SetDebugMode(true);
jint.BreakPoints.Add(new BreakPoint(4, 22, "x == 2;")); // Line 4, Char 22 => return x*x; only if x == 2

jint.Break += (sender, info) =>
{
    Console.WriteLine(info.Locals["x"].Value); // Displays 2
};

jint.Run(@"
    var i = 3; 
    function square(x) { 
        return x*x; // breakpoint here
    }
    
    square(1);
    square(2); // will break only on this line
    square(3);
");

Extensibility

This allows any standard application to handle simple debugging, but also to create a very simple graphical editor which would display a script, break points, and steps while executing. This application would just need to register to the Step event to get every step executed and display it to the editor, as the locals, watch list and call stack.

New Comment on "Quick Start"

tormaroe — Thu, 23 Jun 2011 10:05:45 GMT

The example code on this page contains a lot of small errors - like missing closing brackets all over the place.

Updated Wiki: Home

sebastienros — Fri, 10 Jun 2011 18:40:38 GMT

Project Description

Jint is a script engine based on the Javascript language. Using Jint, developers can provide fully scriptable applications, execute .NET code without compiling, or create external configuration logic, using the most used script language.
Jint aims at providing every JavaScript functionalities to .NET applications, and bindings to .NET languages can be done in both sides. Jint scripts can use any .NET object from your application, and use every part of the .NET base class library.

Differences with other script engines

Jint is different as it doesn't use CodeDomProvider technique which is using compilation under the hood and thus leads to memory leaks as the compiled assemblies can't be unloaded. Moreover, using this technique prevents using dynamically types variables the way JavaScript does, allowing more flexibility in your scripts. On the opposite, Jint embeds it's own parsing logic, and really interprets the scripts. Jint uses the famous ANTLR (http://www.antlr.org) library for this purpose.
As it uses Javascript as its language you don't have to learn a new language, it has proven to be very powerful for scripting purposes, and you can use several text editors for syntax checking.

Usage scenarios

Create applications users can automate by providing a programmable interface. A good example is what VBA is for Microsoft Office applications
Enhance configurability to change your application's behavior and logic without compiling or deploying binaries
Evaluate dynamic code or expressions

Sample usage

Here is a sample in C#, but any .NET language can use Jint. Jint is able to handle all advanced JavaScript techniques decribed on this MSDN article: http://msdn.microsoft.com/en-us/magazine/cc163419.aspx. It currently implements all concepts defined in ECMAScript version 3.0.

script= @"
  function square(x) { 
    return x * x; 
  };
  
  return square(number);
  ";
  
var result = new JintEngine()
  .SetParameter("number", 3)
  .Run(script));

Assert.AreEqual(9, result);

You can also check the actual implemented test suite for more samples.

Implemented artifacts

Standard Javascript elements:
- Objects and methods
- Loops (do, while, for)
- Code blocks and scopes
- Conditional statements (if, switch/case)
- Json
- Property indexers
- Dynamic properties
- Javascript native classes (Math, String, Object, Number)
- Regular expressions
- Functions (declarations plus anonymous functions)
- Prototypes and constructors
.NET bindings
- External objects and values
- External functions to enhance the script resources
- Return value to .NET code
Out of the box Jint Shell application
- Use Jint on the command line

Deployment

Jint is deployed as a part of your application and fits inside a single assembly. Nothing as to be installed on the client machine.

Roadmap

0.8 - All javascript languages artifacts as of ECMAScript 3.0
0.9 - Beta phase - All javascript core methods are implemented (Math, slice, ...)
1.0 - Positive feedback from Beta
1.1 - ECMAScript 5.0 elements

New Comment on "Documentation"

agehack — Wed, 08 Jun 2011 21:42:28 GMT

Hi anybody i having some strange trouble situation. I don't know where is problem can be. The objective is to store some objects in Array variable. Objects is type of my own class described in JavaScript. // Array defenition: var Users = []; // Class defenition: var DOUser = function(userSet, id) { // (Constructor code) var MemberCode = -1; var XCode = -1; var Nickname = "???"; var ID = -1; var UIN = -1; var Sent = -1; var Money = -1; var Respect = -1; } // So, i trying to store few objects of type DOUser in my array Users. I using Array.push(<object>) to add objects to array: var user = // DOUser instance creation .... Users.push(user); Well, anything is fine. BUT! Object is not exists in array after that. I don't know what to do IT IS A VERY BIG PROBLEM!!! (I mean, 4 objects of class DOUser were added to array Users, but after that Users is empty (size is 4, but all items == undefined/null), PLEASE, HELP ME, DEVELOPER! I think this is some bug! P.S i use v0.8 binaries. I don't want to update.

Updated Wiki: Returning values

sebastienros — Tue, 10 May 2011 22:06:01 GMT

Returning values

Scripts can return values to the host application. The return keywords is used for this purpose.

JintEngine engine = new JintEngine();
var result = engine.Run("return 0;");
Console.WriteLine(result); // Displays 0

Also, if a statement is evaluated, the return value will be the value of this statement:

Console.WriteLine(engine.Run("var a = true;")); // Displays true

New Comment on "Quick Start"

brainslugs83 — Fri, 15 Apr 2011 07:16:33 GMT

Ahh... looks like I just needed to make my class public so JInt could see it! Oops.

New Comment on "Quick Start"

brainslugs83 — Fri, 15 Apr 2011 07:10:40 GMT

I'm having a hard time exposing custom .NET objects to JInt scripts using engine.SetParameter... maybe there is another way. Time to hit the manual.

New Comment on "Passing external functions to scripts"

jstrider39 — Tue, 11 Jan 2011 04:53:40 GMT

When I run the MessageBox example below I get security exception; Does any one know why? Is it because Jint does not know how to handle the DialogResult return type? engine.SetFunction("alert", new Jint.Delegates.Func<string, DialogResult>(MessageBox.Show)); engine.Run(@" function square(x) { alert('Hi Mike'); return x * x; }"); engine.Run("square(5);");

New Comment on "Overview"

InfertilityTreat — Sun, 02 Jan 2011 06:07:01 GMT

So what are the straightforward (simplified) benefits for one utilizing JavaScript already? Lauren

New Comment on "Overview"

InfertilityTreat — Sun, 02 Jan 2011 06:06:20 GMT

So what are the straightforward (simplified) benefits for one utilizing JavaScript already? Lauren - <a href="http://infertilitytreatments4women.com/">Infertility Treatments 4 Women</a>

New Comment on "Using .NET classes from scripts"

Verious — Fri, 31 Dec 2010 17:05:01 GMT

In .NET 4.0 the security model has changed, most .NET classes that will be added to Jint using the SetParameter() function should be tagged with the SecurityTransparent() attribute to avoid causing an elevation of privileges (unless your class needs a specific permission, such as writing to the file system). See the following example: // The assembly will be similar to the following: using System.Security; [assembly: SecurityTransparent()] namespace Sample { public class SampleClass { public void DoSomething() { // Do something interesting. } } } // The application will contain code similar to the following: SampleClass sample = new SampleClass(); jint.SetParameter("sample", sample);

New Comment on "Quick Start"

samshulie — Tue, 28 Dec 2010 19:53:24 GMT

Interesting to know that the Javascript is getting integrated as dll....cool!!! but, Tested (VS 2005 console app) with each sample mentioned in this page all works fine. except the last one which is not compiling at line below. engine.SetFunction("square", new Func<double, double>(a => { return a * a; })) Hope a negative approach on comment is not abuse. I was just highlighting and playin around.

New Comment on "Returning values"

mwawrusch — Sun, 17 Oct 2010 13:57:31 GMT

Technically it is not be an error, but very bad style, and a lot of fun when you minify scripts that contain missing semicolons.

Updated Wiki: Home

sebastienros — Fri, 27 Aug 2010 18:16:26 GMT

Project Description

Differences with other script engines

Usage scenarios

Create applications users can automate by providing a programmable interface. A good example is what VBA is for Microsoft Office applications
Enhance configurability to change your application's behavior and logic without compiling or deploying binaries
Evaluate dynamic code or expressions

Sample usage

script= @"
  function square(x) { 
    return x * x; 
  };
  
  return square(number);
  ";
  
var result = new JintEngine()
  .SetParameter("number", 3)
  .Run(script));

Assert.AreEqual(9, result);

You can also check the actual implemented test suite for more samples.

Implemented artifacts

Standard Javascript elements:
- Objects and methods
- Loops (do, while, for)
- Code blocks and scopes
- Conditional statements (if, switch/case)
- Json
- Property indexers
- Dynamic properties
- Javascript native classes (Math, String, Object, Number)
- Regular expressions
- Functions (declarations plus anonymous functions)
- Prototypes and constructors
.NET bindings
- External objects and values
- External functions to enhance the script resources
- Return value to .NET code
Out of the box Jint Shell application
- Use Jint on the command line

Deployment

Jint is deployed as a part of your application and fits inside a single assembly. Nothing as to be installed on the client machine.

Roadmap

0.8 - All javascript languages artifacts as of ECMAScript 3.0
0.9 - Beta phase - All javascript core methods are implemented (Math, slice, ...)
1.0 - Positive feedback from Beta
1.1 - ECMAScript 5.0 elements

People behind Jint

Jint is a project managed by the people of Evaluant and is a part of its R&D developments

New Comment on "Returning values"

janus03 — Thu, 22 Jul 2010 06:41:11 GMT

Actually, the semicolon is optional...

New Comment on "Exposing Javascript functions to the CLR"

tom_peres — Tue, 06 Apr 2010 15:49:39 GMT

I'm really trying to find the way to use this method. But... i can't use them. Can you help me?