/// <summary>
/// This method is invoked by the data services framework to obtain the URI clients should use when making retrieve (ie. GET)
/// requests to the stream(ie. Media Resource). This metadata is needed when constructing the payload for the Media Link Entry
/// associated with the stream (aka Media Resource).
///
/// If IDataServiceStreamProvider.GetReadStreamUri returns a valid Uri, we return that as the Uri to the Media Resource.
/// Otherwise we take the given Media Link Entry uri, and construct the default Media Resource Uri.
/// </summary>
/// <param name="entity">The entity associated with the stream for which a “read stream” is to be obtained</param>
/// <param name="operationContext">A reference to the context for the current operation.</param>
/// <param name="mediaLinkEntryUri">Uri to the Media Link Entry.</param>
/// <returns>The URI clients should use when making retrieve (ie. GET) requests to the stream(ie. Media Resource).</returns>
internal Uri GetReadStreamUri(object entity, DataServiceOperationContext operationContext, string mediaLinkEntryUri)
{
Debug.Assert(entity != null, "entity != null");
Debug.Assert(operationContext != null, "operationContext != null");
Uri readStreamUri = InvokeApiCallAndValidateHeaders("IDataServiceStreamProvider.GetReadStreamUri", () => this.StreamProvider.GetReadStreamUri(entity, operationContext), operationContext);
if (readStreamUri != null)
{
if (!readStreamUri.IsAbsoluteUri)
{
throw new InvalidOperationException(Strings.DataServiceStreamProviderWrapper_GetReadStreamUriMustReturnAbsoluteUriOrNull);
}
else
{
return(readStreamUri);
}
}
else
{
return(new Uri(DataServiceStreamProviderWrapper.GetStreamEditMediaUri(mediaLinkEntryUri), UriKind.RelativeOrAbsolute));
}
}