/// <summary>
/// Wrap the DSPLinqQuery with a PagedQueryProvider
/// </summary>
/// <param name="source">The DSPLinqQuery Instance</param>
/// <returns>A new queryable which supports paging</returns>
private IQueryable WrapWithPagingProvider(IQueryable source)
{
if (customPagingEnabled)
{
IQueryProvider provider = new AstoriaUnitTests.Tests.PagedQueryProvider(
this,
source.Provider,
null,
null,
new AstoriaUnitTests.Tests.CountManager());
return(DSPLinqQueryProvider.CreateQuery(provider, source.Expression));
}
else
{
return(source);
}
}
/// <summary>Invokes the specified service operation.</summary>
/// <param name="serviceOperation">The service operation to invoke.</param>
/// <param name="parameters">The parameters for the service operation. Their types will match the types of the declared parameters for the service operation.</param>
/// <returns>The result of the service operation.
/// If the service operation is declared to return void, this method should return null.
/// Otherwise the method should return object of the type declared as the return type for the service operation.</returns>
public object InvokeServiceOperation(ServiceOperation serviceOperation, object[] parameters)
{
Func <Object[], Object> operation;
if (this.dataSource.ServiceOperations.TryGetValue(serviceOperation.Name, out operation))
{
object result = operation(parameters);
if (result is IQueryable)
{
// in order to further compose on top of this query, we need to turn this into a DSPLinqQuery
return(WrapWithPagingProvider(DSPLinqQueryProvider.CreateQuery((IQueryable)result)));
}
return(result);
}
throw new InvalidOperationException("Specified service operation is not implemented by the data source");
}
/// <summary>Internal constructor.</summary>
/// <param name="queryProvider">The query provider to use for this query.</param>
/// <param name="queryExpression">The query expression for this query (the DSP version).</param>
internal DSPLinqQuery(DSPLinqQueryProvider queryProvider, Expression queryExpression)
{
this.queryProvider = queryProvider;
this.queryExpression = queryExpression;
}
/// <summary>Helper strongly typed method to create the query for a resource set root.</summary>
/// <typeparam name="TElement">The instance type of a single resource in the set.</typeparam>
/// <param name="resourceSet">The resource set to get the query root for.</param>
/// <returns>Strongly typed query for the resource set root.</returns>
private System.Linq.IQueryable GetTypedQueryRootForResourceSet <TElement>(ResourceSet resourceSet)
{
IQueryable source = DSPLinqQueryProvider.CreateQuery(this.dataSource.GetResourceSetEntities(resourceSet.Name).Cast <TElement>().AsQueryable());
return(WrapWithPagingProvider(source));
}
/// <summary>Wraps a query in a new query which will translate the DSP query into a LINQ to Objects runnable query
/// and run it on the provided <paramref name="underlyingQuery"/>.</summary>
/// <param name="underlyingQuery">The underlying (LINQ to Objects) query to wrap.</param>
/// <returns>A new query which can handle the DSP expressions and run them on top of the <pararef name="underlyingQuery"/>.</returns>
public static IQueryable CreateQuery(IQueryable underlyingQuery)
{
DSPLinqQueryProvider provider = new DSPLinqQueryProvider(underlyingQuery.Provider);
return(CreateQuery(provider, underlyingQuery.Expression));
}