Page History

...

public abstract LoginPage extends BasePage implements UserPermissions {

  public abstract User getUser();

}

..
/**
 * Interface for any page/component that holds references to the current system
 * User. 
 */
public interface UserPermissions {
   User getUser();
}

...

These are the more delicate parts of the compiler API that the majority of people will need to worry about during any integration efforts.

 Known Issues / Limitations

• Compiler Errors - Despite the substantially large number of unit tests set up and thorough usage of many different types of expressions Tapestry users are still currently running in to fatal/non caught runtime errors when some of their OGNL expressions are compiled. In some instances these errors are blockers and they must either wait for someone to fix the bug (after being posted to http://jira.opensymphony.com/browse/OGNL correctly) or re-work their expression to get around the error. I (jesse) generally try to fix these reported errors within a day or two (or sooner) when I can and immediately deploy the fixes to the OGNL snapshot maven2 repository. This doesn't mean that the vast majority of expressions won't compile fine, but it is something to keep in mind when you decide how to integrate the compiler logic in to your own framework.

• Compile vs. normal expression evaluation - The current Tapestry implementation compiles OGNL expressions in both development AND production modes. This has the undesirable side effect of causing needless multiple method invocations on objects when compiling as well as the general overhead of performing compilations at all when people are just developing applications and not serving them in production environments. It is hoped that when OGNL becomes final this special development mode can go back to using normal OGNL expression evaluation during development and save compilation for production environments, but until then we've been worried about giving people false positives when testing their applications. Meaning - something may evaluate just fine when using Ognl.getValue(OgnlContext, Object root, String expression but fail completely when they deploy their app to production and the compiler kicks in. If you framework doesn't handle separate modes or have this kind of state set up it is something to keep in mind. The number of JIRA issues reported has gone way down since this all started but they do still trickle in which is enough to know that things aren't yet 100% reliable. I'm sure the plethora of Struts/WebWork/etc users available should be enough to iron out any remaining issues found but it's something to keep in mind.

• Snapshot Repository - The current maven2 location of the OGNL development/snapshot release are all made to http://opencomponentry.com/repository/m2-snapshot-repo/, while releases go out to ibiblio as per normal. If someone has a better place for these release to be made please feel free to contact jesse ( jkuhnert at gmail.com) with accessor information / instructions.