Dynamics 365 - How to execute batch operations using the Web API (C# code)

The documentation of Dynamics 365 for Customer Engagement apps version 9.x has a section that specifies the details about how to execute batch operations using the Web API at https://docs.microsoft.com/en-us/dynamics365/customer-engagement/developer/webapi/execute-batch-operations-using-web-api.

Unfortunately it does not provide a sample code (in C#) for how to compose the batch request and handle respective response.

So here is the one that I have built for my project:

	public async Task<List<HttpResponseMessage>> SendBatchRequestAsync(List<HttpMessageContent> httpContents)
	{
	if (httpContents == null)
	{
	throw new ArgumentNullException(nameof(httpContents));
	}
	string batchName = $"batch_{Guid.NewGuid()}";
	MultipartContent batchContent = new MultipartContent("mixed", batchName);
	string changesetName = $"changeset_{Guid.NewGuid()}";
	MultipartContent changesetContent = new MultipartContent("mixed", changesetName);
	httpContents.ForEach((c) => changesetContent.Add(c));
	batchContent.Add(changesetContent);
	return await SendBatchRequestAsync(batchContent);
	}
	public async Task<List<HttpResponseMessage>> SendBatchRequestAsync(MultipartContent batchContent)
	{
	HttpRequestMessage batchRequest = new HttpRequestMessage
	{
	Method = HttpMethod.Post,
	RequestUri = new Uri(_httpClient.BaseAddress.AbsoluteUri.Trim() + "$batch")
	};
	batchRequest.Content = batchContent;
	batchRequest.Headers.Add("Prefer", Settings.ClientOptions.DefaultRequestHeaders["Prefer"]);
	batchRequest.Headers.Add("OData-MaxVersion", "4.0");
	batchRequest.Headers.Add("OData-Version", "4.0");
	batchRequest.Headers.Add("Accept", "application/json");
	HttpResponseMessage response = await _httpClient.SendAsync(batchRequest);
	MultipartMemoryStreamProvider body = await response.Content.ReadAsMultipartAsync();
	List<HttpResponseMessage> contents = await ReadHttpContents(body);
	return contents;
	}
	private async Task<List<HttpResponseMessage>> ReadHttpContents(MultipartMemoryStreamProvider body)
	{
	List<HttpResponseMessage> results = new List<HttpResponseMessage>();
	if (body?.Contents != null)
	{
	foreach (HttpContent c in body.Contents)
	{
	if (c.IsMimeMultipartContent())
	{
	results.AddRange(await ReadHttpContents((await c.ReadAsMultipartAsync())));
	}
	else if (c.IsHttpResponseMessageContent())
	{
	HttpResponseMessage responseMessage = await c.ReadAsHttpResponseMessageAsync();
	if (responseMessage != null)
	{
	results.Add(responseMessage);
	}
	}
	else
	{
	HttpResponseMessage responseMessage = DeserializeToResponse(await c.ReadAsStreamAsync());
	if (responseMessage != null)
	{
	results.Add(responseMessage);
	}
	}
	}
	}
	return results;
	}
	private HttpResponseMessage DeserializeToResponse(Stream stream)
	{
	HttpResponseMessage response = new HttpResponseMessage();
	MemoryStream memoryStream = new MemoryStream();
	stream.CopyTo(memoryStream);
	response.Content = new ByteArrayContent(memoryStream.ToArray());
	response.Content.Headers.Add("Content-Type", "application/http;msgtype=response");
	return response.Content.ReadAsHttpResponseMessageAsync().Result;
	}

view raw dynamics-365-batch-request.cs hosted with ❤ by GitHub

The SendBatchRequestAsync method has two overloads which can be used for two different scenarios:

• Execute a batch request that is composed of a list of individual requests, each of them can be in turn a change set, or
• Execute a list of requests that are grouped into a single change set.

Example 1:

	string batchName = $"batch_{Guid.NewGuid()}";
	MultipartContent batchContent = new MultipartContent("mixed", batchName);
	string changesetName = $"changeset_{Guid.NewGuid()}";
	MultipartContent changesetContent = new MultipartContent("mixed", changesetName);
	string taskJson1 = "{\"subject\":\"Task 1 in batch\",\"regardingobjectid_account_task@odata.bind\":\"[Organization URI]/api/data/v9.0/accounts(00000000-0000-0000-000000000001)\"}";
	changesetContent.Add(CreateHttpMessageContent(HttpMethod.Post, "tasks", 1, taskJson1));
	string taskJson2 = "{\"subject\":\"Task 2 in batch\",\"regardingobjectid_account_task@odata.bind\":\"[Organization URI]/api/data/v9.0/accounts(00000000-0000-0000-000000000001)\"}";
	changesetContent.Add(CreateHttpMessageContent(HttpMethod.Post, "tasks", 2, taskJson2));
	batchContent.Add(changesetContent);
	batchContent.Add(CreateHttpMessageContent(HttpMethod.Get, "Account_Tasks?$select=subject"));
	List<HttpResponseMessage> responses = await SendBatchRequestAsync(batchContent);

view raw dynamics-365-batch-request-example1.cs hosted with ❤ by GitHub

Example 2:

	List<HttpMessageContent> httpContents = new List<HttpMessageContent>();
	for (int i = 1; i <= 5; i++)
	{
	string taskJson = "{\"subject\":\"Task " + i.ToString() + " in batch\",\"regardingobjectid_account_task@odata.bind\":\"[Organization URI]/api/data/v9.0/accounts(00000000-0000-0000-000000000001)\"}";
	httpContents.Add(CreateHttpMessageContent(HttpMethod.Post, "tasks", i, taskJson));
	}
	List<HttpResponseMessage> responses = await SendBatchRequestAsync(httpContents);

view raw dynamics-365-batch-request-example2.cs hosted with ❤ by GitHub

Utility method to create HttpMessageContent:

	public HttpMessageContent CreateHttpMessageContent(HttpMethod httpMethod, string requestUri, int contentId = 0, string content = null)
	{
	string baseUrl = _httpClient.BaseAddress.AbsoluteUri.Trim();
	if (!requestUri.StartsWith(baseUrl))
	{
	requestUri = baseUrl + requestUri;
	}
	HttpRequestMessage requestMessage = new HttpRequestMessage(httpMethod, requestUri);
	HttpMessageContent messageContent = new HttpMessageContent(requestMessage);
	messageContent.Headers.Remove("Content-Type");
	messageContent.Headers.Add("Content-Type", "application/http");
	messageContent.Headers.Add("Content-Transfer-Encoding", "binary");
	// only GET request requires Accept header
	if (httpMethod == HttpMethod.Get)
	{
	requestMessage.Headers.Add("Accept", "application/json");
	}
	else
	{
	// request other than GET may have content, which is normally JSON
	if (!string.IsNullOrEmpty(content))
	{
	StringContent stringContent = new StringContent(content);
	stringContent.Headers.ContentType = MediaTypeHeaderValue.Parse("application/json;type=entry");
	requestMessage.Content = stringContent;
	}
	messageContent.Headers.Add("Content-ID", contentId.ToString());
	}
	return messageContent;
	}

view raw CreateHttpMessageContent.cs hosted with ❤ by GitHub