/// <summary>
/// Creates an <see cref="ODataBatchOperationRequestMessage"/> for writing an operation of a batch request.
/// </summary>
/// <param name="method">The Http method to be used for this request operation.</param>
/// <param name="uri">The Uri to be used for this request operation.</param>
/// <param name="contentId">The (optional) content ID to be included in this request operation.</param>
/// <returns>The message that can be used to write the request operation.</returns>
public ODataBatchOperationRequestMessage CreateOperationRequestMessage(HttpMethod method, Uri uri, string contentId)
{
this.ValidateWriterReady();
if (this.writingResponse)
{
this.ThrowODataException(Strings.ODataBatchWriter_CannotCreateRequestOperationWhenWritingResponse);
}
if (this.changeSetBoundary == null)
{
// only allow GET requests for query operations
if (method != HttpMethod.Get)
{
this.ThrowODataException(Strings.ODataBatchWriter_InvalidHttpMethodForQueryOperation(method.ToText()));
}
// do not allow content-id for query operations
if (contentId != null)
{
this.ThrowODataException(Strings.ODataBatchWriter_ContentIdNotSupportedForQueryOperations(contentId));
}
this.InterceptException(this.IncreaseBatchSize);
}
else
{
// allow all methods except for GET
if (method == HttpMethod.Get)
{
this.ThrowODataException(Strings.ODataBatchWriter_InvalidHttpMethodForChangeSetRequest(method.ToText()));
}
this.InterceptException(this.IncreaseChangeSetSize);
}
ExceptionUtils.CheckArgumentNotNull(uri, "uri");
this.InterceptException(() => uri = ODataBatchWriterUtils.BuildAbsoluteUri(uri, this.settings.BaseUri));
// write pending message data (headers, response line) for a previously unclosed message/request
this.WritePendingMessageData(true);
// create the new request operation
this.CurrentOperationRequestMessage = new ODataBatchOperationRequestMessage(this.outputStream, method, uri, this);
this.SetState(BatchWriterState.OperationCreated);
// write the operation's start boundary string
this.WriteStartBoundaryForOperation();
// write the headers, request line and (optional) Content-ID
ODataBatchWriterUtils.WriteRequestPreamble(this.batchWriter, method, uri, contentId);
return(this.CurrentOperationRequestMessage);
}
/// <summary>
/// Writes the start boundary for an operation. This is either the batch or the changeset boundary.
/// </summary>
private void WriteStartBoundaryForOperation()
{
if (this.changeSetBoundary == null)
{
ODataBatchWriterUtils.WriteStartBoundary(this.batchWriter, this.batchBoundary);
this.batchStartBoundaryWritten = true;
}
else
{
ODataBatchWriterUtils.WriteStartBoundary(this.batchWriter, this.changeSetBoundary);
}
}
/// <summary>
/// Ends an active changeset; this can only be called after WriteStartChangeset and only once for each changeset.
/// </summary>
public void WriteEndChangeset()
{
this.ValidateWriterReady();
// write pending message data (headers, response line) for a previously unclosed message/request
this.WritePendingMessageData(true);
// change the state first so we validate the change set boundary before attempting to write it.
string currentChangeSetBoundary = this.changeSetBoundary;
this.SetState(BatchWriterState.ChangeSetCompleted);
// write the end boundary for the change set
ODataBatchWriterUtils.WriteEndBoundary(this.batchWriter, currentChangeSetBoundary);
}
/// <summary>
/// Ends a batch; can only be called after WriteStartBatch has been called and if no other active changeset or operation exist.
/// </summary>
public void WriteEndBatch()
{
this.ValidateWriterReady();
// write the start boundary for the batch if not written
if (!this.batchStartBoundaryWritten)
{
Debug.Assert(this.CurrentOperationMessage == null, "If not batch boundary was written we must not have an active message.");
ODataBatchWriterUtils.WriteStartBoundary(this.batchWriter, this.batchBoundary);
}
// write pending message data (headers, response line) for a previously unclosed message/request
this.WritePendingMessageData(true);
this.SetState(BatchWriterState.BatchCompleted);
// write the end boundary for the batch
ODataBatchWriterUtils.WriteEndBoundary(this.batchWriter, this.batchBoundary);
}
/// <summary>
/// Creates an <see cref="ODataBatchOperationResponseMessage"/> for writing an operation of a batch response.
/// </summary>
/// <returns>The message that can be used to write the response operation.</returns>
public ODataBatchOperationResponseMessage CreateOperationResponseMessage()
{
this.ValidateWriterReady();
if (!this.writingResponse)
{
this.ThrowODataException(Strings.ODataBatchWriter_CannotCreateResponseOperationWhenWritingRequest);
}
this.WritePendingMessageData(true);
this.CurrentOperationResponseMessage = new ODataBatchOperationResponseMessage(this.outputStream, this);
this.SetState(BatchWriterState.OperationCreated);
// write the operation's start boundary string
this.WriteStartBoundaryForOperation();
// write the headers, request line and (optional) Content-ID
ODataBatchWriterUtils.WriteResponsePreamble(this.batchWriter);
return(this.CurrentOperationResponseMessage);
}
/// <summary>
/// Starts a new changeset; can only be called after WriteStartBatch and if no other active operation or changeset exists.
/// </summary>
public void WriteStartChangeset()
{
this.ValidateWriterReady();
// write pending message data (headers, response line) for a previously unclosed message/request
this.WritePendingMessageData(true);
// important to do this first since it will set up the change set boundary.
this.SetState(BatchWriterState.ChangeSetStarted);
Debug.Assert(this.changeSetBoundary != null, "this.changeSetBoundary != null");
// reset the size of the current changeset and increase the size of the batch
this.ResetChangeSetSize();
this.InterceptException(this.IncreaseBatchSize);
// write the boundary string
ODataBatchWriterUtils.WriteStartBoundary(this.batchWriter, this.batchBoundary);
this.batchStartBoundaryWritten = true;
// write the change set headers
ODataBatchWriterUtils.WriteChangeSetPreamble(this.batchWriter, this.changeSetBoundary);
}
/// <summary>
/// Sets a new writer state; verifies that the transition from the current state into new state is valid.
/// </summary>
/// <param name="newState">The writer state to transition into.</param>
private void SetState(BatchWriterState newState)
{
this.InterceptException(() => this.ValidateTransition(newState));
switch (newState)
{
case BatchWriterState.BatchStarted:
Debug.Assert(!this.batchStartBoundaryWritten, "The batch boundary must not be written before calling WriteStartBatch.");
break;
case BatchWriterState.ChangeSetStarted:
Debug.Assert(this.changeSetBoundary == null, "this.changeSetBoundary == null");
this.changeSetBoundary = ODataBatchWriterUtils.CreateChangeSetBoundary(this.writingResponse);
break;
case BatchWriterState.ChangeSetCompleted:
Debug.Assert(this.changeSetBoundary != null, "this.changeSetBoundary != null");
this.changeSetBoundary = null;
break;
}
this.state = newState;
}
