Creating OpenEMM extensions

[rkarallus]

Hello everybody,

my current task is to create an OpenEMM extension. I am working with OpenEMM now for 3 days and my feelings are mixed. I think it has a great approach but many weaknesses, especially when it comes to extensions. As far as I can see OpenEMM is not built to be extended.

The intention of this posting is to bring my pain with extension development to the core developer team so they might adjust the application in future releases.

I know there is a extension document (http://ignum.dl.sourceforge.net/project ... ces120.pdf). I read it with patience and tried to adjust my concept to the rules in there. However, technically this document does not go far enough. How would I start to create a backoffice extension, for example?

However, I worked through the sources and tried to find out how to create a mostly independent extension on my own. My conclusion is: it is not possible to create such an extension. The main problems are:
1) There is no concept for extension localization but to overwrite the OpenEMM localization files and add own entries (which is a problem in regard to migrations). It would have been so easy. Just add the message-ressource key to each bean:message tag and each extension would have been able to use an own message-ressource.
2) The "dynamic" navigation structure is not extendable without overwriting navigation/*.properties and message-ressource files. The other way would be to overwrite the JSP files. Both is a migration problem. Another weakness of the dynamic navigation concept is that the message ressource key is not concidered in the navigation/*.properties (and the taglib that processes that files). If it is not extensions cannot define their own keys without overwriting the OpenEMM localization files.

These are the first points that I found. If I find more, I will add them here. Please do not see my posting as an affront, but see it as a try to help OpenEMM to become even better as it is today.

Thank you
Regards
Ronny

[maschoff]

We agree that OpenEMM does not offer an extension concept right now and that this would be a valuable addition (actually, we had it on the public roadmap for quite some time before we removed it).

The problem is that we do not have the resources right now to develop it on our own. However, if someone from the community wants to do the job and contribute the code, he/she is very welcome!

We would happily support the development with access to core developers and information, we would integrate the extension code into the mainline so that all othery OpenEMM users can use it as well and we would set up a central extension repository to host and promote OpenEMM extensions from third parties.