(Lianja) Azure Storage: CORS Preflight Blob Request

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

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// 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.

loRest = createobject("CkRest")

// Connect to the Azure Storage Blob Service
llBTls = .T.
lnPort = 443
llBAutoReconnect = .T.
// In this example, the storage account name is "chilkat".
llSuccess = loRest.Connect("chilkat.blob.core.windows.net",lnPort,llBTls,llBAutoReconnect)
if (llSuccess <> .T.) then
    ? loRest.LastErrorText
    release loRest
    return
endif

// Provide Azure Cloud credentials for the REST call.
loAzAuth = createobject("CkAuthAzureStorage")
loAzAuth.AccessKey = "AZURE_ACCESS_KEY"
// The account name used here should match the 1st part of the domain passed in the call to Connect (above).
loAzAuth.Account = "chilkat"
loAzAuth.Scheme = "SharedKey"
loAzAuth.Service = "Blob"
// This causes the "x-ms-version: 2020-08-04" header to be automatically added.
loAzAuth.XMsVersion = "2020-08-04"
llSuccess = loRest.SetAuthAzureStorage(loAzAuth)

// 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.
llSuccess = loRest.AddHeader("Origin","www.contoso.com")
// The Access-Control-Request-Method is the HTTP method (such as GET, POST, PUT, etc.) of the actual request.
llSuccess = loRest.AddHeader("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.)
lcResponseStr = loRest.FullRequestNoBody("OPTIONS","/test")
if (loRest.LastMethodSuccess <> .T.) then
    ? loRest.LastErrorText
    release loRest
    release loAzAuth
    return
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 (loRest.ResponseStatusCode <> 200) then
    // Examine the request/response to see what happened.
    ? "response status code = " + str(loRest.ResponseStatusCode)
    ? "response status text = " + loRest.ResponseStatusText
    ? "response header: " + loRest.ResponseHeader
    ? "response body (if any): " + lcResponseStr
    ? "---"
    ? "LastRequestStartLine: " + loRest.LastRequestStartLine
    ? "LastRequestHeader: " + loRest.LastRequestHeader
    release loRest
    release loAzAuth
    return
endif

? "Success: Preflight Blob Request is accepted."


release loRest
release loAzAuth