public override void InitializeContext(IConnectionInfo cxInfo, object context, QueryExecutionManager executionManager)
{
// This method gets called after a DataServiceContext has been instantiated. It gives us a chance to
// perform further initialization work.
//
// And as it happens, we have an interesting problem to solve! The typed data service context class
// that Astoria's EntityClassGenerator generates handles the ResolveType delegate as follows:
//
// return this.GetType().Assembly.GetType (string.Concat ("<namespace>", typeName.Substring (19)), true);
//
// Because LINQPad subclasses the typed data context when generating a query, GetType().Assembly returns
// the assembly of the user query rather than the typed data context! To work around this, we must take
// over the ResolveType delegate and resolve using the context's base type instead:
var dsContext = (DataServiceContext)context;
var typedDataServiceContextType = context.GetType ().BaseType;
dsContext.ResolveType = name => typedDataServiceContextType.Assembly.GetType
(typedDataServiceContextType.Namespace + "." + name.Split ('.').Last ());
// The next step is to feed any supplied credentials into the Astoria service.
// (This could be enhanced to support other authentication modes, too).
var props = new AstoriaProperties (cxInfo);
dsContext.Credentials = props.GetCredentials ();
// Finally, we handle the SendingRequest event so that it writes the request text to the SQL translation window:
dsContext.SendingRequest += (sender, e) => executionManager.SqlTranslationWriter.WriteLine (e.Request.RequestUri);
}
static XmlReader GetSchemaReader(AstoriaProperties props)
{
var uri = new DataServiceContext (new Uri (props.Uri)).GetMetadataUri ();
var settings = new XmlReaderSettings ();
XmlResolver resolver = new XmlUrlResolver ();
// If credentials have been supplied, feed these in as we're querying the schema:
resolver.Credentials = props.GetCredentials ();
settings.XmlResolver = resolver;
return XmlReader.Create (uri.ToString (), settings);
}