(PowerBuilder) Lower-Level REST API Methods (Google Cloud Storage)

The FullRequest* methods, such as FullRequestBinary, FullRequestMultipart, FullRequestNoBody, FullRequestStream, FullRequestString, etc. are high-level REST API methods that both send the request and receive the response. It is often the case that an application needs make a REST call, but with a finer level of control. The Chilkat REST API provides this feature. An application can break a REST call into the following parts:

1. Send the HTTP request. (via the SendReq* methods)
2. Receive the HTTP response header. (ReadResponseHeader)
3. Receive the HTTP response body. (via the ReadRespBody* methods)

This example demonstrates a REST call using SendReqStringBody, ReadResonseHeader, and ReadRespBodyString.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

integer li_rc
integer li_Success
oleobject loo_GAuth
oleobject loo_Rest
integer li_BAutoReconnect
oleobject loo_JsonReqBody
oleobject loo_PObjVersioning
integer li_ResponseStatusCode
string ls_ResponseBodyStr

// This example demonstrates a REST call using SendReqStringBody, ReadResonseHeader, and ReadRespBodyString.
// It will create a bucket in Google Cloud Storage.

// It requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

loo_GAuth = create oleobject
li_rc = loo_GAuth.ConnectToNewObject("Chilkat_9_5_0.AuthGoogle")
if li_rc < 0 then
    destroy loo_GAuth
    MessageBox("Error","Connecting to COM object failed")
    return
end if
// Obtain an access token as shown in one of the following examples:
// See Get Access Token using a Service Account JSON Key
// See Get Access Token using a P12 File

loo_Rest = create oleobject
li_rc = loo_Rest.ConnectToNewObject("Chilkat_9_5_0.Rest")

// Connect using TLS.
li_BAutoReconnect = 1
li_Success = loo_Rest.Connect("www.googleapis.com",443,1,li_BAutoReconnect)

// Provide the authentication credentials (i.e. the access key)
li_Success = loo_Rest.SetAuthGoogle(loo_GAuth)

// Build the JSON request body for creating a bucket.
// The only required property is the "name", but we'll add more
// to make a better example..
loo_JsonReqBody = create oleobject
li_rc = loo_JsonReqBody.ConnectToNewObject("Chilkat_9_5_0.JsonObject")

li_Success = loo_JsonReqBody.AddStringAt(-1,"name","chilkat-bucket-c")
li_Success = loo_JsonReqBody.AddStringAt(-1,"kind","storage#bucket")
li_Success = loo_JsonReqBody.AddStringAt(-1,"location","US")
li_Success = loo_JsonReqBody.AddObjectAt(-1,"versioning")

loo_PObjVersioning = loo_JsonReqBody.ObjectOf("versioning")
li_Success = loo_PObjVersioning.AddBoolAt(-1,"enabled",1)
destroy loo_PObjVersioning

// Show the HTTP request body we'll be sending.
Write-Debug loo_JsonReqBody.Emit()

// Add the required query parameter.
// See https://cloud.google.com/storage/docs/json_api/v1/buckets/insert
li_Success = loo_Rest.AddQueryParam("project","chilkattest-1050")

// Add the Content-Type HTTP request header.
li_Success = loo_Rest.AddHeader("Content-Type","application/json; charset=UTF-8")

// Send the REST HTTP request.
li_Success = loo_Rest.SendReqStringBody("POST","/storage/v1/b",loo_JsonReqBody.Emit())
if li_Success <> 1 then
    Write-Debug loo_Rest.LastErrorText
    destroy loo_GAuth
    destroy loo_Rest
    destroy loo_JsonReqBody
    return
end if

// Read the response header.
li_ResponseStatusCode = loo_Rest.ReadResponseHeader()
if li_ResponseStatusCode < 0 then
    // We were unable to receive the response header.
    Write-Debug loo_Rest.LastErrorText
    destroy loo_GAuth
    destroy loo_Rest
    destroy loo_JsonReqBody
    return
end if

if li_ResponseStatusCode <> 200 then
    // The response was not successful.  We'll still need to receive 
    // the response body, which may contain an error message from the server.
    // If the response has no body, then the method for reading the
    // response body can still be called.  It will simply return with an empty
    // response body.

    // We can examine the response header and status text:
    Write-Debug "Response status text: " + loo_Rest.ResponseStatusText
    Write-Debug "Response header: " + loo_Rest.ResponseHeader
end if

// Read the response body.  In this case we're expecting it to be JSON..
ls_ResponseBodyStr = loo_Rest.ReadRespBodyString()
if loo_Rest.LastMethodSuccess <> 1 then
    // We were unable to receive the response body.
    // Note: If the response did not include a body (such as for cases where
    // the Content-Length header is 0, or if the response status code implicitly
    // indicates no body, then ReadRespBodyString returns cktrue, and the
    // responseBodyString will be an empty string.
    Write-Debug loo_Rest.LastErrorText
    destroy loo_GAuth
    destroy loo_Rest
    destroy loo_JsonReqBody
    return
end if

// Show the JSON response.
Write-Debug "Json Response: " + ls_ResponseBodyStr


destroy loo_GAuth
destroy loo_Rest
destroy loo_JsonReqBody