(JavaScript) 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.

Note: This example requires Chilkat v11.0.0 or greater.

Note

This example is intended for running within a Chilkat.Js embedded JavaScript engine. All Chilkat JavaScript examples require Chilkat v11.4.0 or greater.

var success = false;

// 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.

var gAuth = new CkAuthGoogle();
// 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

var rest = new CkRest();

// Connect using TLS.
var bAutoReconnect = true;
success = rest.Connect("www.googleapis.com",443,true,bAutoReconnect);

// Provide the authentication credentials (i.e. the access key)
success = rest.SetAuthGoogle(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..
var jsonReqBody = new CkJsonObject();
success = jsonReqBody.AddStringAt(-1,"name","chilkat-bucket-c");
success = jsonReqBody.AddStringAt(-1,"kind","storage#bucket");
success = jsonReqBody.AddStringAt(-1,"location","US");

var objVersioning = new CkJsonObject();
jsonReqBody.AppendObject2("versioning",objVersioning);
success = objVersioning.AddBoolAt(-1,"enabled",true);

// Show the HTTP request body we'll be sending.
console.log(jsonReqBody.Emit());

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

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

// Send the REST HTTP request.
success = rest.SendReqStringBody("POST","/storage/v1/b",jsonReqBody.Emit());
if (success == false) {
    console.log(rest.LastErrorText);
    return;
}

// Read the response header.
var responseStatusCode = rest.ReadResponseHeader();
if (responseStatusCode < 0) {
    // We were unable to receive the response header.
    console.log(rest.LastErrorText);
    return;
}

if (responseStatusCode !== 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:
    console.log("Response status text: " + rest.ResponseStatusText);
    console.log("Response header: " + rest.ResponseHeader);
}

// Read the response body.  In this case we're expecting it to be JSON..
var responseBodyStr = rest.ReadRespBodyString();
if (rest.LastMethodSuccess !== true) {
    // 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.
    console.log(rest.LastErrorText);
    return;
}

// Show the JSON response.
console.log("Json Response: " + responseBodyStr);