Associating an Object with other Objects and Properties of those Objects
- by alzoid
I am looking for some help with designing some functionality in my application. I already have something similar designed but this problem is a little different.
Background:
In my application we have different Modules. Data in each module can be associated to other modules. Each Module is represented by an Object in our application.
Module 1 can be associated with Module 2 and Module 3. Currently I use a factory to provide the proper DAO for getting and saving this data.
It looks something like this:
class Module1Factory {
public static Module1BridgeDAO createModule1BridgeDAO(int moduleid) {
switch (moduleId)
{
case Module.Module2Id: return new Module1_Module2DAO();
case Module.Module3Id: return new Module1_Module3DAO();
default: return null;
}
}
}
Module1_Module2 and Module1_Module3 implement the same BridgeModule interface. In the database I have a Table for every module (Module1, Module2, Module3). I also have a bridge table for each module (they are many to many) Module1_Module2, Module1_Module3 etc.
The DAO basically handles all code needed to manage the association and retrieve its own instance data for the calling module. Now when we add new modules that associate with Module1 we simply implement the ModuleBridge interface and provide the common functionality.
New Development
We are adding a new module that will have the ability to be associated with other Modules as well as specific properties of that module. The module is basically providing the user the ability to add their custom forms to our other modules. That way they can collect additional information along with what we provide.
I want to start associating my Form module with other modules and their properties. Ie if Module1 has a property Category, I want to associate an instance From data with that property.
There are many Forms. If a users creates an instance of Module2, they may always want to also have certain form(s) attached to that Module2 instance. If they create an instance of Module2 and select Category 1, then I may want additional Form(s) created.
I prototyped something like this:
Form
FormLayout (contains the labels and gui controls)
FormModule (associates a form with all instances of a module)
Form Instance (create an instance of a form to be filled out)
As I thought about it I was thinking about making a new FormModule table/class/dao for each Module and Property that I add. So I might have:
FormModule1
FormModule1Property1
FormModule1Property2
FormModule1Property3
FormModule1Property4
FormModule2
FormModule3
FormModule3Property1
Then as I did previously, I would use a factory to get the proper DAO for dealing with all of these. I would hand it an array of ids representing different modules and properties and it would return all of the DAOs that I need to call getForms(). Which in turn would return all of the forms for that particular bridge.
Some points
This will be for a new module so I dont need to expand on the factory code I provided. I just wanted to show an example of what I have done in the past.
The new module can be associated with: Other Modules (ie globally for any instance of that module data), Other module properties (ie only if the Module instance has a certian value in one of its properties)
I want to make it easy for developers to add associations with other modules and properties easily
Can any one suggest any design patterns or strategy's for achieving this?
If anything is unclear please let me know.
Thank you,
Al
