PureBasic

Azure Storage: CORS Preflight Blob Request

See more Azure Cloud Storage Examples

Azure Storage Blob Service REST API: Sample code to send a CORS pre-flight blob request. PureBasic

IncludeFile "CkRest.pb"
IncludeFile "CkAuthAzureStorage.pb"

Procedure ChilkatExample()

    success.i = 0

    ; Azure Blob Service Example: CORS Preflight Blob Request
    ; See also: https://msdn.microsoft.com/en-us/library/azure/dn535599.aspx

    ; This example requires the Chilkat API to have been previously unlocked.
    ; See Global Unlock Sample for sample code.

    rest.i = CkRest::ckCreate()
    If rest.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; Connect to the Azure Storage Blob Service
    bTls.i = 1
    port.i = 443
    bAutoReconnect.i = 1
    ; In this example, the storage account name is "chilkat".
    success = CkRest::ckConnect(rest,"chilkat.blob.core.windows.net",port,bTls,bAutoReconnect)
    If success <> 1
        Debug CkRest::ckLastErrorText(rest)
        CkRest::ckDispose(rest)
        ProcedureReturn
    EndIf

    ; Provide Azure Cloud credentials for the REST call.
    azAuth.i = CkAuthAzureStorage::ckCreate()
    If azAuth.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkAuthAzureStorage::setCkAccessKey(azAuth, "AZURE_ACCESS_KEY")
    ; The account name used here should match the 1st part of the domain passed in the call to Connect (above).
    CkAuthAzureStorage::setCkAccount(azAuth, "chilkat")
    CkAuthAzureStorage::setCkScheme(azAuth, "SharedKey")
    CkAuthAzureStorage::setCkService(azAuth, "Blob")
    ; This causes the "x-ms-version: 2021-08-06" header to be automatically added.
    CkAuthAzureStorage::setCkXMsVersion(azAuth, "2021-08-06")
    success = CkRest::ckSetAuthAzureStorage(rest,azAuth)

    ; Note: The application does not need to explicitly set the following
    ; headers: x-ms-date, Authorization.  These headers
    ; are automatically set by Chilkat.

    ; The preflight blob request requires the following two HTTP headers.
    ; The Origin is the domain from which the actual request will be issued.
    success = CkRest::ckAddHeader(rest,"Origin","www.contoso.com")
    ; The Access-Control-Request-Method is the HTTP method (such as GET, POST, PUT, etc.) of the actual request.
    success = CkRest::ckAddHeader(rest,"Access-Control-Request-Method","PUT")

    ; The expected response is a 202 response status code with no response body.
    ; The name of the container or blob resource in this example is "test". (Replace "test" with your container name.)
    responseStr.s = CkRest::ckFullRequestNoBody(rest,"OPTIONS","/test")
    If CkRest::ckLastMethodSuccess(rest) <> 1
        Debug CkRest::ckLastErrorText(rest)
        CkRest::ckDispose(rest)
        CkAuthAzureStorage::ckDispose(azAuth)
        ProcedureReturn
    EndIf

    ; When successful, the Azure Storage service will respond with a 200 response code,
    ; with no response body.

    ; If CORS is not enabled or no matching rule is found for the request, 
    ; then a 403 status code is returned, with the following status text:
    ; "CORS not enabled or no matching rule found for this request."
    If CkRest::ckResponseStatusCode(rest) <> 200
        ; Examine the request/response to see what happened.
        Debug "response status code = " + Str(CkRest::ckResponseStatusCode(rest))
        Debug "response status text = " + CkRest::ckResponseStatusText(rest)
        Debug "response header: " + CkRest::ckResponseHeader(rest)
        Debug "response body (if any): " + responseStr
        Debug "---"
        Debug "LastRequestStartLine: " + CkRest::ckLastRequestStartLine(rest)
        Debug "LastRequestHeader: " + CkRest::ckLastRequestHeader(rest)
        CkRest::ckDispose(rest)
        CkAuthAzureStorage::ckDispose(azAuth)
        ProcedureReturn
    EndIf

    Debug "Success: Preflight Blob Request is accepted."


    CkRest::ckDispose(rest)
    CkAuthAzureStorage::ckDispose(azAuth)


    ProcedureReturn
EndProcedure