Xbase++ Requires Chilkat v11.0.0+

Lower-Level REST API Methods (Google Cloud Storage)

See more REST Examples

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.

Xbase++

LOCAL nSuccess
LOCAL oGAuth
LOCAL oRest
LOCAL nBAutoReconnect
LOCAL oJsonReqBody
LOCAL oObjVersioning
LOCAL nResponseStatusCode
LOCAL cResponseBodyStr

nSuccess := 0

//  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.

oGAuth := CreateObject("Chilkat.AuthGoogle")
//  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

oRest := CreateObject("Chilkat.Rest")

//  Connect using TLS.
nBAutoReconnect := 1
nSuccess := oRest:Connect("www.googleapis.com", 443, 1, nBAutoReconnect)

//  Provide the authentication credentials (i.e. the access key)
nSuccess := oRest:SetAuthGoogle(oGAuth)

//  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..
oJsonReqBody := CreateObject("Chilkat.JsonObject")
nSuccess := oJsonReqBody:AddStringAt(-1, "name", "chilkat-bucket-c")
nSuccess := oJsonReqBody:AddStringAt(-1, "kind", "storage#bucket")
nSuccess := oJsonReqBody:AddStringAt(-1, "location", "US")

oObjVersioning := CreateObject("Chilkat.JsonObject")
oJsonReqBody:AppendObject2("versioning", oObjVersioning)
nSuccess := oObjVersioning:AddBoolAt(-1, "enabled", 1)

//  Show the HTTP request body we'll be sending.
? oJsonReqBody:Emit()

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

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

//  Send the REST HTTP request.
nSuccess := oRest:SendReqStringBody("POST", "/storage/v1/b", oJsonReqBody:Emit())
IF (nSuccess == 0)
    ? oRest:LastErrorText
    oGAuth:destroy()
    oRest:destroy()
    oJsonReqBody:destroy()
    oObjVersioning:destroy()
    RETURN
ENDIF

//  Read the response header.
nResponseStatusCode := oRest:ReadResponseHeader()
IF (nResponseStatusCode < 0)
    //  We were unable to receive the response header.
    ? oRest:LastErrorText
    oGAuth:destroy()
    oRest:destroy()
    oJsonReqBody:destroy()
    oObjVersioning:destroy()
    RETURN
ENDIF

IF (nResponseStatusCode != 200)
    //  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:
    ? "Response status text: " + oRest:ResponseStatusText
    ? "Response header: " + oRest:ResponseHeader
ENDIF

//  Read the response body.  In this case we're expecting it to be JSON..
cResponseBodyStr := oRest:ReadRespBodyString()
IF (oRest:LastMethodSuccess != 1)
    //  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.
    ? oRest:LastErrorText
    oGAuth:destroy()
    oRest:destroy()
    oJsonReqBody:destroy()
    oObjVersioning:destroy()
    RETURN
ENDIF

//  Show the JSON response.
? "Json Response: " + cResponseBodyStr

oGAuth:destroy()
oRest:destroy()
oJsonReqBody:destroy()
oObjVersioning:destroy()