Does CRM context allow for structuring code in a non-nested way? - silverlight

Question

I'm building a Silverlight Web Resource which is intended to integrate into a form, and it needs to know all of the following information:
id of the current user
id of teams current user belongs to
id of current user's security roles
I'm working in an early-bound kind of way, added a Service Reference to the OData endpoint (http://server/org/XRMservices/2011/OrganizationData.svc) which in turn provides me with the context (let's name it cmtestcontext, which is its actual name in code).
I access data through this class (I didn't create it, I just googled it out of the net some time ago: this is a stripped-down, keep-it-short version)
public class QueryInterface
{
//NOTE: ServiceReference1 is the name of the OData service reference
//Add Service Reference -> point to CRM OData url
public ServiceReference1.cmtextcontext CrmContext;
public QueryInterface()
{
var crmServerUrl = (string)GetContext().Invoke("getServerUrl");
if (crmServerUrl.EndsWith("/")) crmServerUrl = crmServerUrl.Substring(0, crmServerUrl.Length - 1);
Uri ODataUri = new Uri(crmServerUrl + "/xrmservices/2011/organizationdata.svc/", UriKind.Absolute);
CrmContext = new cmtestContext(ODataUri) { IgnoreMissingProperties = true };
}
}
The class allows me to sort of fetch in one line, as follows (actual code snippet enveloped in a dummy method to make it copy-pastable):
void RetrieveAllInformationFromCRM()
{
QueryInterface qi = new QueryInterface();
List<Guid> allData = new List<Guid>();
//NOTE: STEP 1 - USER ID
//NOTE: Since this is a web resource, I can cheat and use Xrm.Page.context.getUserId()
//NOTE: Remove the extra '{}' from the result for it to be parsed!
allData.Add(new Guid(qi.GetContext().Invoke("getUserId").ToString().Substring(1,36)));
//NOTE: STEP 2a - TEAM MEMBERSHIP FOR USER
//NOTE: TeamMembership entity links users to teams in a N:N relationship
qi.crmContext.TeamMembershipSet.BeginExecute(new AsyncCallback((result) =>
{
var teamMemberships = qi.crmContext.TeamMembershipSet.EndExecute(result)
.Where(tm => tm.TeamId.HasValue && (tm.SystemUserId ?? Guid.Empty) == userId)
.Select(tm => tm.TeamId.Value);
//NOTE: STEP 2b - TEAMS RELATED TO TEAMMEMBERSHIPS
qi.crmContext.TeamSet.BeginExecute(new AsyncCallback((result2) =>
{
var teamDetails = qi.crmContext.TeamSet.EndExecute(result2)
.Where(t => teamMemberships.Contains(t.TeamId));
foreach (var team in teamDetails)
allData.Add(team.TeamId);
//NOTE: FINAL STEP - allData is filled and ready to be used.
}), null);
}), null);
}
In the code above, my FINAL STEP picks up allData and processes it, and the flow goes on. My concern is, if/when I'll need to modify this "reader" method I'll have to cut and paste the "final" code around to ensure it's placed after all the reads. I'd like it way better if I could just make the reads follow one another, so I could do this:
void MyReaderMethod()
{
ReadEverything();
ProcessData();
}
Basically, can you just wait for a request to finish ? Hanging UI is a non-issue, I'd just wrap the code in a BackgroundWorker along with a "Please Wait" splash.

Answer 1

The nicest (IMO) is to convert the Async method calls (a requirement of Silverlight) into Task based calls.
With tasks you can easily seperate the query from the result action.
Then using the Async BCL's (via nuget) you can use async/await (if you are not using VS2012, then Tasks are still nicer to work with, you will just have to use continuations)
This example is for late bound, but you can modify it for your needs
public Task<OrganizationResponse> ExecuteAsync(OrganizationRequest request)
{
return Task.Factory.FromAsync<OrganizationResponse>(
(callback, state) => Begin(() => service.BeginExecute(request, callback, state)),
service.EndExecute,
null);
}
Then you can use it like
async void MyReaderMethod()
{
//TODO:wrap in try/catch
var result = await ExecuteAsync( ... );
ProcessData(result);
}
Or for VS 2010
void MyReaderMethod()
{
ExecuteAsync( ... ).ContinueWith(task =>{
//TODO: Error handling
ProcessData(task.Result);
});
}