Overview

The xweld-expression module provides a small but powerful standalone module for representing Boolean or mathematical expressions, and parsing them from Strings that can be evaluated into either a Boolean or Numeric result. While there are several other Java expression languages available – SpEL, OGNL, MVEL, and JBoss EL, to name a few – the xweld-expression module is extremely lightweight and provides only those primitives typically required by the <xweld/> suite of tools. Because of its simplicity, it is extremely easy to set up and use.

One primary motivation for the expression class library is to support Permissions in xweld-security that use a context when they are evaluated. For example, expressions support the notion of context-sensitive permissions, to control enabling or disabling GUI controls according to a user's metadata, such as that user's region and product set. That said, xweld-expression is based on a technology-agnostic API allowing other expression language implementations to be integrated should the need arise in your application.

The xweld-expression language supports the following functionality:

  • Double or Boolean evaluation results
  • Expressions containing quoted String values and numeric literals and lists
  • Expressions containing Boolean relational operators, such as >, < ,=, & and |
  • Expressions referencing fields or methods of a context object passed at evaluation time using reflection
  • Expressions supporting parameters supplied at evaluation time
  • Expressions checking whether a field, parameter, or literal is contained in another list of values

The module documentation is available here:

Contact Us

For more information, please contact us at

Copyright

Copyright © 1999-2012 Free North Alliance Inc. All Rights Reserved.

The contents of this web site, all images, text, grahics and software are the sole property of Free North Alliance Inc. and its agents. Unauthorized use or transmission is strictly forbidden by international copyright law.

Members

Administrator: John Free, John Free
Contributor: Greg Shields, Hany Mesha, John Free, Rick Noel, Roger Dunn
Architect: Hany Mesha, John Free