Showing posts with label Open Access. Show all posts
Showing posts with label Open Access. Show all posts

July 13, 2012

Generated objects, property exists? (or not!)

The ORM of choice of my employer is Telerik Open Access. It supports both forward and reverse mapping. When doing SCRUM development, it gives us the flexibility to quickly add some database columns, tables, foreign key relations etc. in the database and then generate the business objects in our data layer.

My problem

In a particular project the customer opted for record tracking. Who -and when- created (e.g.) a person in the database, and who (when) had it changed.
The catch though:
  • it's not required for all tables. 
  • The creation / modification user is only known in the software (no database trigger solution).

Problem solved?

One part of the solution was to edit the Telerik Open Access class generation templates. In those templates we added a (default!) constructor. In the constructor we set the creator and creation date properties. Adding / implementing INotifyPropertyChanged handled the modification properties. The generation of the business classes was no problem, but compiling the project was another story...
Not every business class had the creation properties, so we faced "some" compiler errors.

Problem solved!

Refelection saved the day. Instead of setting the property straight forward in the constructor:
 this._createUser="new creator";  
it's 'decorated' with an if:
 if(!this.GetType().GetProperty("CreateUser") == null)  
   this.GetType().GetProperty("CreateUser").SetValue(this,"new creator",null);  

Now we can (re-)generate the class model without the headache of modifying 70+ constructors for objects without tracking (or the need to add 40+ constructers  when not generated).