Lambda2Js

This is an ExpressionTree (lambda) to Javascript converter.

It is portable, so that you can use it in most environments.

It's purpose is to convert a C# expression tree (from Linq namespace) to a syntatically correct javascript code.

It can be extended to customize the mapping of expressions:

• support custom static methods, instead of emiting code that would otherwise depend on external javascript
• support custom types, converting method calls and properties accordingly

It is well tesded, and won't break. More than 70 tests passing.

This project uses Semantic versioning.

Installing NuGet package:

PM> Install-Package Lambda2Js

Samples

Converting lambda with boolean and numeric operations:

Expression<Func<MyClass, object>> expr = x => x.PhonesByName["Miguel"].DDD == 32 || x.Phones.Length != 1;
var js = expr.CompileToJavascript();
// js = PhonesByName["Miguel"].DDD===32||Phones.length!==1

Converting lambda with LINQ expression, containing a inner lambda:

Expression<Func<MyClass, object>> expr = x => x.Phones.FirstOrDefault(p => p.DDD > 10);
var js = expr.CompileToJavascript();
// js = System.Linq.Enumerable.FirstOrDefault(Phones,function(p){return p.DDD>10;})

Converting lambda with Linq Select method:

Expression<Func<string[], IEnumerable<char>>> expr = array => array.Select(x => x[0]);
var js = expr.CompileToJavascript(
    new JavascriptCompilationOptions(
        JsCompilationFlags.BodyOnly | JsCompilationFlags.ScopeParameter,
        new[] { new LinqMethods(), }));
// js = array.map(function(x){return x[0];})

Clone using ToArray and targeting ES6:

Expression<Func<string[], IEnumerable<string>>> expr = array => array.ToArray();
var js = expr.Body.CompileToJavascript(
    ScriptVersion.Es60,
    new JavascriptCompilationOptions(new LinqMethods()));
// js = [...array]

Developing custom plugins

You can develop and use some prebuilt plugins. See the readme.md in the Plugins folder.