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See also this tutorial for more information about using the ASP.NET web API client libraries.

Making a GET request

Let's read orders created after a particular date. For security reasons, query results need to be paged, so we have to specify the $top option (and optionally $skip).

string publicKey = "0c6b33651708eb09c8a8d6036b79d739";
string secretKey = "3025c89ebaab20b71e0e42744239bf50";
string method = "get";
string accept = "application/json, text/javascript, */*"; 
string timestamp = DateTime.UtcNow.ToString("o");	// 2013-11-11T10:15:54.1731069Z
string url = "http://localhost:1260/odata/v1/Orders?$top=10&$filter=CreatedOnUtc gt datetime'2013-02-20T00:00:00'";

First, we create the message representation.

var uri = new Uri(url);		// decode url
if (uri.Query != null && uri.Query.Length > 0)
{
	url = string.Concat(uri.GetLeftPart(UriPartial.Path), HttpUtility.UrlDecode(uri.Query));
}

var messageRepresentation = string.Join("\n",
   	method.ToLower(),
   	"",
   	accept.ToLower(),
   	url.ToLower(),
   	timestamp,
 	publicKey.ToLower()
); 

It looks like:

get
application/json, text/javascript, */*
http://localhost:1260/odata/v1/orders?$top=10&$filter=createdonutc gt datetime'2013-02-20t00:00:00'
2013-11-11T10:15:54.1731069Z
0c6b33651708eb09c8a8d6036b79d739

Now, we can calculate the HMAC signature by using our secret key.

 string signature = CreateSignature(secretKey, messageRepresentation);	// hWce6V2KA0kkB0GBbIK0GSw5QAcS3+vj+m+WN/8k9EE=

We have all the information to set up the request, so we create a web request object and pass the required headers.

var request = (HttpWebRequest)WebRequest.Create(url);
request.Method = method;
request.UserAgent = "My shopping data consumer v.1.0";
request.Accept = accept;
request.Headers.Add("Accept-Charset", "UTF-8");
request.Headers.Add("SmartStore-Net-Api-PublicKey", publicKey);
request.Headers.Add("SmartStore-Net-Api-Date", timestamp);
request.Headers.Add("Authorization", "SmNetHmac1 " + signature);

The complete header looks like this:

User-Agent: My shopping data consumer v.1.0
Accept: application/json, text/javascript, */*
Accept-Charset: UTF-8
SmartStore-Net-Api-PublicKey: 0c6b33651708eb09c8a8d6036b79d739
SmartStore-Net-Api-Date: 2013-11-11T10:15:54.1731069Z
Authorization: SmNetHmac1 hWce6V2KA0kkB0GBbIK0GSw5QAcS3+vj+m+WN/8k9EE=

Making a POST request

Posting means inserting data via API. This example shows how to add a new order note "Hello world!" to the order with ID 152. Here is the function to create the MD5 hash of the request body:

public string CreateContentMd5Hash(byte[] content)
{
  	string result = "";
   	if (content != null && content.Length > 0)
   	{
   		using (var md5 = MD5.Create())
   		{
   			byte[] hash = md5.ComputeHash(content);
   			result = Convert.ToBase64String(hash);
   		}
   	}
   	return result;
}

No other variables have changed.

string content = "{\"OrderId\":152,\"Note\":\"Hello world!\",\"DisplayToCustomer\":false,\"CreatedOnUtc\":\"2013-11-09T11:15:00\"}";

byte[] data = Encoding.UTF8.GetBytes(content);
string contentMd5Hash = CreateContentMd5Hash(data);

string method = "post";
string timestamp = DateTime.UtcNow.ToString("o");	// 2013-11-11T19:44:04.9378268Z
string url = "http://localhost:1260/odata/v1/OrderNotes"; 

We add the same header fields as in the previous example, and additionally: 

request.ContentLength = data.Length;
request.ContentType = "application/json; charset=utf-8";
request.Headers.Add("Content-MD5", contentMd5Hash);	// optional

Then, we write the content into the request stream.

using (var stream = request.GetRequestStream())
{
  	stream.Write(data, 0, data.Length);
}

The message representation is as follows:

post
lgifXydL3FhffpTIilkwOw==
application/json, text/javascript, */*
http://localhost:1260/odata/v1/ordernotes
2013-11-11T19:44:04.9378268Z
0c6b33651708eb09c8a8d6036b79d739

The header looks like this:

User-Agent: My shopping data consumer v.1.0
Accept: application/json, text/javascript, */*
Accept-Charset: UTF-8
SmartStore-Net-Api-PublicKey: 0c6b33651708eb09c8a8d6036b79d739
SmartStore-Net-Api-Date: 2013-11-11T19:44:04.9378268Z
Content-Type: application/json; charset=utf-8
Content-Length: 100
Content-MD5: lgifXydL3FhffpTIilkwOw==
Authorization: SmNetHmac1 ejKxxtHNJYHCtBglZPg+cbSs3YTrA50pkfTHtVb1PMo=

As a general rule, POST, PUT and PATCH are returning the added or changed record. For example:

{ 
"odata.metadata":"http://localhost:1260/odata/v1/$metadata#OrderNotes/@Element",
"OrderId":152,
"Note":"Hello world!",
"DisplayToCustomer":false,
"CreatedOnUtc":"2013-11-09T11:15:00","Id":692
}

Processing the response

Example of reading the response into a string:

HttpWebResponse webResponse = null;
string response;
    
try
{
 	webResponse = request.GetResponse() as HttpWebResponse;
    using (var reader = new StreamReader(webResponse.GetResponseStream(), Encoding.UTF8))
    {
    	response = reader.ReadToEnd();
    }
}
catch (WebException wexc) { /* ... */ }
catch (Exception exc) { /* ... */ }
finally
{
  	if (webResponse != null)
   	{
   		webResponse.Close();
   		webResponse.Dispose();
   	}
}

JSON data can be easily parsed into dynamic or strongly typed objects using Json.NET. This example deserializes a JSON string into a list of customers.

 public class Customer
{
   	public string Id { get; set; }
   	public string CustomerGuid { get; set; }
   	public string Email { get; set; }
	// more properties...
}
    
JObject json = JObject.Parse(response);
string metadata = (string)json["odata.metadata"];
    
if (!string.IsNullOrWhiteSpace(metadata) && metadata.EndsWith("#Customers"))
{
   	List<Customer> customers = json["value"].Select(x => x.ToObject<Customer>()).ToList();
}

Dynamic JSON parsing might look like this:

dynamic dynamicJson = JObject.Parse(response);
    
foreach (dynamic customer in dynamicJson.value)
{
	string str = string.Format("{0} {1} {2}", customer.Id, customer.CustomerGuid, customer.Email);
	Debug.WriteLine(str);
}

 

 

 

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