The ServerGrove blog has posted the latest in their series focusing on various components in the Symfony2 framework. This latest post looks at the ExpressionLanguage component, functionality that allows you to execute "expressions" easily.
This is the 10th post in our series on Symfony2 components and we will cover the latest component added to Symfony: the ExpressionLanguage component. This component was added in version 2.4 and provides a way to have dynamic aspects in static configurations. For example, it can be used to evaluate expressions in configuration files, create a DSL ,or build a business rules engine.
The tutorial shows you how to get it installed (via Composer) and provides a simple "before" and "after" example, the first using eval and the second using ExpressionEngine to reproduce the same effect. They note that the evaluation of the expression isn't the same thing as compiling it and re-execution will always take the same amount of time. The post then talks about some of the syntax, functions and caching features of the component. It dives a little bit deeper and looks at some of the internals of the component as well.