rikulo/el

Rikulo EL (Expression Language) is an implementation of the Unified Expression Language specification plus some enhancements for and in Dart.

#Rikulo EL

Rikulo EL is an implementation of the Unified Expression Language specification plus enhancements for and in Dart.

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Rikulo EL is distributed under the Apache 2.0 License.

##Install from Dart Pub Repository

Add this to your pubspec.yaml (or create it):

dependencies:
  rikulo_el:

Then run the Pub Package Manager (comes with the Dart SDK):

pub install

##Install from Github for Bleeding Edge Stuff

To install stuff that is still in development, add this to your pubspec.yam:

dependencies:
  rikulo_el:
    git: git://github.com/rikulo/el.git

For more information, please refer to Pub: Dependencies.

##Usage

Using Rikulo EL is straightforward.

import 'dart:mirrors' show reflect;
import 'package:rikulo_el/el.dart';

class Person {
  String name;
  Person(this.name);
}

void main() {
  //Prepare an expression factory.
  ExpressionFactory ef = new ExpressionFactory();

  //Prepare the expression script
  //expression inside #{...} is to be evaluated
  String script = 'Hello, #{person.name}!'; 

  //Prepare an expression context.
  ELContext ctx = new ELContext();
  ctx.variableMapper.setVariable('person',
      ef.createVariable(new Person('Rikulo')));
  
  //Parse the script and create a value expression which expect a String type
  ValueExpression ve = ef.createValueExpression(ctx, script, reflect('').type);
  
  //Evaluate the expression and return the evaluated result
  print(ve.getValue(ctx)); //'Hello, Rikulo!'
}

For more examples, please refer to here, here and here.

##Notes to Contributors

###Test and Debug

You are welcome to submit bugs and feature requests. Or even better if you can fix or implement them!

###Create Addons

Rikulo is easy to extend. The simplest way to enhance Rikulo is to create a new repository and add your own great widgets and libraries to it.

###Fork Rikulo

If you'd like to contribute back to the core, you can fork this repository and send us a pull request, when it is ready.

Please be aware that one of Rikulo's design goals is to keep the sphere of API as neat and consistency as possible. Strong enhancement always demands greater consensus.

If you are new to Git or GitHub, please read this guide first.