/// <summary>
/// Obtain the DataServiceContext from the incoming enumerable
/// </summary>
/// <param name="items">An IEnumerable that may be a DataServiceQuery or QueryOperationResponse object</param>
/// <returns>DataServiceContext instance associated with the input</returns>
private static DataServiceContext GetContextFromItems(IEnumerable <T> items)
{
Debug.Assert(items != null, "items != null");
DataServiceQuery <T> dataServiceQuery = items as DataServiceQuery <T>;
if (dataServiceQuery != null)
{
DataServiceQueryProvider queryProvider = dataServiceQuery.Provider as DataServiceQueryProvider;
Debug.Assert(queryProvider != null, "Got DataServiceQuery with unknown query provider.");
DataServiceContext context = queryProvider.Context;
Debug.Assert(context != null, "Query provider must always have valid context.");
return(context);
}
QueryOperationResponse queryOperationResponse = items as QueryOperationResponse;
if (queryOperationResponse != null)
{
Debug.Assert(queryOperationResponse.Results != null, "Got QueryOperationResponse without valid results.");
DataServiceContext context = queryOperationResponse.Results.Context;
Debug.Assert(context != null, "Materializer must always have valid context.");
return(context);
}
throw new ArgumentException(Strings.DataServiceCollection_CannotDetermineContextFromItems);
}
/// <summary>
/// query object
/// </summary>
/// <param name="expression">expression for query</param>
/// <param name="provider">query provider for query</param>
private DataServiceQuery(Expression expression, DataServiceQueryProvider provider)
{
Debug.Assert(null != provider.Context, "null context");
Debug.Assert(expression != null, "null expression");
Debug.Assert(provider is DataServiceQueryProvider, "Currently only support Web Query Provider");
this.queryExpression = expression;
this.queryProvider = provider;
}
private static DataServiceContext GetContextFromItems(IEnumerable <T> items)
{
DataServiceQuery <T> query = items as DataServiceQuery <T>;
if (query != null)
{
DataServiceQueryProvider provider = query.Provider as DataServiceQueryProvider;
return(provider.Context);
}
QueryOperationResponse response = items as QueryOperationResponse;
if (response == null)
{
throw new ArgumentException(Strings.DataServiceCollection_CannotDetermineContextFromItems);
}
return(response.Results.Context);
}
private DataServiceQuery(System.Linq.Expressions.Expression expression, DataServiceQueryProvider provider)
{
this.queryExpression = expression;
this.queryProvider = provider;
}
internal DataServiceOrderedQuery(Expression expression, DataServiceQueryProvider provider) : base(expression, provider)
{
}
