On 5/24/07, John Goulah <[EMAIL PROTECTED]> wrote:
What are some of the patterns people are using to implement this? Any other thoughts?
People are going to hate me for saying this... but I've started to adopt the Java bean paradigm for my Catalyst app. To the point where I even have a whole MyApp::Bean hierarchy (skip to the bottom if you're already gearing up for a big paradigm fight). Why? I had this nice little CRUD app that did what I wanted. But then I started looking at adding XMLRPC support, and other things. Reviewing my code, I realized I couldn't just call my existing methods because they all assumed things like: 1) Parameters would come in an HTML::Widget or some CGI like interface (param, params, parameters, etc). When dealing with XMLRPC this isn't true. 2) Errors would just be stuffed into the stash. Which is fine if you're going to render them, but isn't as nice for other solutions. Suppose I needed to add SOAP support later. Errors should come via SOAP exceptions. 3) That the context would be able to provide things like the current user. With XMLRPC, sometimes the external app would need to feed the user to my backend, so what's in the context would be wrong. 4) The general assumption that the content in the stash was going to be rendered. Some methods would fetch several things from the database and stash them because that's what the templates would need. But with XMLRPC, it was a waste. I happen to have done some work with JavaEE and am familiar with the design pattern, so that's the solution I reached for. It's still MVC, but the controller has two parts. A) The servlet, which corresponds to Catalyst controllers. But the servlets don't do any of the actual work; they just marshal the data between the HTTP interface and your beans... B) The beans, which contain all the business logic. These interact with the model, manipulate it, and then return the results to the servlets. Beans should never be written with the transport (HTTP, SOAP, XMLRPC) or view in mind: all that's the job of the servlet. If the view needs extra data from the model for this transport, then it's the job of the servlet to fetch that. This might or might not work for you. I'm not interested in starting a design paradigm war; I understand they all have their own strengths and weaknesses. Just thought I'd throw this out there. _______________________________________________ List: Catalyst@lists.rawmode.org Listinfo: http://lists.rawmode.org/mailman/listinfo/catalyst Searchable archive: http://www.mail-archive.com/catalyst@lists.rawmode.org/ Dev site: http://dev.catalyst.perl.org/
