Best pattern to load enumerated values from DAL using WCF RIA Services
- by Dale Halliwell
I would like to be able to load several RIA entitysets in a single call without chaining/nesting several small LoadOperations together so that they load sequentially.
I have several pages that have a number of comboboxes on them. These comboboxes are populated with static values from a database (for example status values).
Right now I preload these values in my VM by one method that strings together a series of LoadOperations for each type that I want to load. For example:
public void LoadEnums() {
context.Load(context.GetMyStatusValues1Query()).Completed += (s, e) =>
{
this.StatusValues1 = context.StatusValues1;
context.Load(context.GetMyStatusValues2()).Completed += (s1, e1) =>
{
this.StatusValues2 = context.StatusValues2;
context.Load(context.GetMyStatusValues3Query()).Completed += (s2, e2) =>
{
this.StatusValues3 = context.StatusValues3;
(....and so on)
};
};
};
};
While this works fine, it seems a bit nasty. Also, I would like to know when the last loadoperation completes so that I can load whatever entity I want to work on after this, so that these enumerated values resolve properly in form elements like comboboxes and listboxes. (I think) I can't do this easily above without creating a delegate and calling that on the completion of the last loadoperation.
So my question is: does anyone out there know a better pattern to use, ideally where I can load all my static entitysets in a single LoadOperation?
