Creating an Authority Using REST (VB)
[This document supports a preliminary release of a software product that may be changed substantially prior to final commercial release. This document is provided for informational purposes only.]
As described in Creating an Authority Using REST, the following Visual Basic example creates an authority. The application performs the following steps:
- Create an XML payload describing the authority.
- Initialize a
WebRequestinstance with the service URI as the parameter. Requests to create an authority are sent to the service. In the request, theContent-Typerequest header is set toapplication/x-ssds+xmlbecause the request payload is XML. - Send the request.
- Process the response. If authority creation is successful, application prints the message accordingly.
Note
Credentials are required to access the service. To make a working sample, update following code and provide id value for the authority.
If you are using the Microsoft Visual Studio integrated development environment, create a console application, and then add the following code.
Imports System
Imports System.Text
Imports System.Net
Imports System.IO
Imports System.Xml.Linq
Namespace CreateAuthorityUsingREST
Class Program
Private userName As String
Private password As String
Const sampleAuthorityId As String = "trworth-vb"
Public Sub testMain() 'ByVal args As String())
Console.Write("Username: ")
userName = Console.ReadLine()
Console.Write("Password: ")
password = ReadPassword()
' When creating an authority, the service must be in scope.
Dim serviceUri As String = String.Format("https://data.database.windows.net/v1/")
Dim authorityUri As String = CreateAuthority(serviceUri)
End Sub 'Main'
Public Function CreateAuthority(ByVal serviceUri As String) As String
Const HttpPostMethod As String = "POST"
Const ssdsContentType As String = "application/x-ssds+xml"
Dim authorityUri As String = ""
If String.IsNullOrEmpty(serviceUri) Then
Throw New ArgumentOutOfRangeException(serviceUri)
End If
Try
' create XML (create authority) request payload.
Dim authorityTemplate As String = "<s:Authority xmlns:s='https://schemas.microsoft.com/sitka/2008/03/'>" & _
" <s:Id>{0}</s:Id>" & _
"</s:Authority>"
Dim requestPayload As String = String.Format(authorityTemplate, sampleAuthorityId)
' Create the request to send.
Dim request As HttpWebRequest = HttpWebRequest.Create(serviceUri)
request.Credentials = New NetworkCredential(userName, password)
' POST=create PUT=update DELETE=delete GET=retrieve
request.Method = HttpPostMethod
Dim Encoding As UTF8Encoding = New UTF8Encoding()
request.ContentLength = Encoding.GetByteCount(requestPayload)
request.ContentType = ssdsContentType
' Write the request data over the wire.
Using reqStm As Stream = request.GetRequestStream()
reqStm.Write(Encoding.GetBytes(requestPayload), 0, _
Encoding.GetByteCount(requestPayload))
End Using
' Get the response and read it in to a string.
Using response As HttpWebResponse = request.GetResponse()
If response.StatusCode = HttpStatusCode.Created Then
Console.WriteLine("Authority created. System assigned version: {0}", response.Headers("ETag"))
' Since current implementation returns response.Headers[HttpResponseHeader.Location]
' value null, construct authority URI
authorityUri = String.Format("https://{0}.data.database.windows.net/v1/", sampleAuthorityId)
Else
Console.WriteLine("Failed to create the authority. Unexpected status code returned: {0}", response.StatusCode.ToString())
End If
End Using
Catch ex As WebException
Using response As HttpWebResponse = ex.Response
If Not response Is Nothing Then
Dim errorMsg As String = ReadResponse(response)
Console.WriteLine(String.Format("Error:{0}", errorMsg))
Console.WriteLine("Unexpected status code returned: {0} ", response.StatusCode.ToString())
End If
End Using
End Try
Return authorityUri
End Function 'CreateAuthority'
Public Function ReadResponse(ByVal response As HttpWebResponse) As String
' Begin by validating our inbound parameters.
'
If (response Is Nothing) Then
Throw New ArgumentNullException("response", "Value cannot be null")
End If
' Then, open up a reader to the response and read the contents to a string
' and return that to the caller.
'
Dim responseBody As String = ""
Using rspStm As Stream = response.GetResponseStream()
Using reader As StreamReader = New StreamReader(rspStm)
responseBody = reader.ReadToEnd()
End Using
End Using
Return responseBody
End Function 'ReadResponse'
Private Function ReadPassword() As String
Dim retval As StringBuilder = New StringBuilder()
Dim keyInfo As ConsoleKeyInfo = Console.ReadKey(True)
While keyInfo.Key <> ConsoleKey.Enter
Console.Write("*")
retval.Append(keyInfo.KeyChar)
keyInfo = Console.ReadKey(True)
End While
Console.WriteLine()
Return retval.ToString()
End Function 'ReadPassword
End Class 'Program'
End Namespace 'CreateAuthorityUsingREST'
To verify that the authority was created, enter the authority URI in the Web browser.
https://<authority-id>.data.database.windows.net/v1/
Note
When querying for non-blob entities your browser need to be aware of the application/x-ssds+xml SSDS content type. For Internet Explorer this can be done by adding a new key in the registry. For more information, see Guidelines and Limitations.
This returns authority metadata as shown in the following sample XML:
<s:Authority
xmlns:s="https://schemas.microsoft.com/sitka/2008/03/"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:x="http://www.w3.org/2001/XMLSchema">
<s:Id>NewAuthorityID</s:Id>
<s:Version>version-number</s:Version>
</s:Authority>