I start a new project this summer, consisting in developing a web version of a proprietary desktop ERP.
The main goal of my company is to be able to propose a web version of its ERP, with all advantages it involves (mobility, possibility of selling SaaS versions, modern look and components ...), without losing any business feature. By this, I mean that us developers can't rework the business side of the app. The main goal is to be able to translate same processes into web application.
Business layer of the older version is not directly reusable, since it's really GUI-dependent. Those business process were rewritten as UML diagrams, which will be used as support for us to develop the new app.
The problem I meet is that I don't know how to deal with process that need user interactions. For example :
confirm : current "thread" (ie validation process) is on hold, waiting for user interaction. After user's choice, it finishes dealing with the current product, and then validates the next one, and so on.
How to deal with this kind of processes with a web application ? Is there some framework, design pattern or something else that permits to write this kind of business processes, able to start and hold like that ?
A solution could be to split those business processes into smaller ones. For my example, we would have 2 sub-processes : the first one checks all products and flags the problematic ones. Then the user has a screen to decide what to do on flagged products, and validates. At this moment we are sure all products are OK, we can start the second sub-process to perform the others operations.
The problem with it is that even if it's pretty simple on this example, it can be really more complicated. Some process have a lot of users interactions like this one, and then could be splitted into 10 subparts. Like I earlier precised, we don't want to modify or rethink business process, to be sure that we lose nothing or introduce new business bugs.
Does someone has an experience about it ? Do you know some way to deal with this kind of desktop-to-web developments ?
There was some misunderstanding about this post, surely related to my poor english expression and vocabulary.
To summarize the problem :
I got a bunch of business workflows described into UML diagrams. They comes from a huge 30-year-old CAMM (production management ERP). The project is to redevelop this application under Java web environment. The main point is that some of those workflows are user-dependent, since, in the middle of the processing, they need a user-interaction. Because web applications are based on a client-server architecture, I don't know how to port them. Reworking/rethinking these workflows is not an option, because it would be too much time-consuming. I need a way to simulate a desktop application on a web app, like Wt, but for Java (i'm not talking about UI but about how to develop workflows ), or to define rules to make those user-dependent workflows web-compatibles.