(Delphi DLL) Send JSON REST Request, Get JSON Response

Demonstrates sending a RESTful JSON request, and receiving a JSON response. This example will create a bucket in Google Cloud Storage (which involves sending and receiving JSON).

Chilkat for Delphi Downloads Chilkat non-ActiveX DLL for Delphi Chilkat ActiveX DLL for Delphi * The examples here use the non-ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, AuthGoogle, JsonObject, Rest;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
gAuth: HCkAuthGoogle;
rest: HCkRest;
bAutoReconnect: Boolean;
jsonReqBody: HCkJsonObject;
pObjVersioning: HCkJsonObject;
jsonResponseStr: PWideChar;

begin
// This example 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.

gAuth := CkAuthGoogle_Create();
// 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

rest := CkRest_Create();

// Connect using TLS.
bAutoReconnect := True;
success := CkRest_Connect(rest,'www.googleapis.com',443,True,bAutoReconnect);

// Provide the authentication credentials (i.e. the access key)
success := CkRest_SetAuthGoogle(rest,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..
jsonReqBody := CkJsonObject_Create();
success := CkJsonObject_AddStringAt(jsonReqBody,-1,'name','chilkat-bucket-c');
success := CkJsonObject_AddStringAt(jsonReqBody,-1,'kind','storage#bucket');
success := CkJsonObject_AddStringAt(jsonReqBody,-1,'location','US');
success := CkJsonObject_AddObjectAt(jsonReqBody,-1,'versioning');

pObjVersioning := CkJsonObject_ObjectOf(jsonReqBody,'versioning');
success := CkJsonObject_AddBoolAt(pObjVersioning,-1,'enabled',True);
CkJsonObject_Dispose(pObjVersioning);

// Show the HTTP request body we'll be sending.
Memo1.Lines.Add(CkJsonObject__emit(jsonReqBody));

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

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

jsonResponseStr := CkRest__fullRequestString(rest,'POST','/storage/v1/b',CkJsonObject__emit(jsonReqBody));
if (CkRest_getLastMethodSuccess(rest) <> True) then
  begin
    Memo1.Lines.Add(CkRest__lastErrorText(rest));
    Exit;
  end;

// Show the JSON response.  (See below for a sample JSON response.)
Memo1.Lines.Add('Json Response: ' + jsonResponseStr);

// {
//  "kind": "storage#bucket",
//  "id": "chilkat-bucket-c",
//  "selfLink": "https://www.googleapis.com/storage/v1/b/chilkat-bucket-c",
//  "projectNumber": "999992999999",
//  "name": "chilkat-bucket-c",
//  "timeCreated": "2016-04-29T21:08:10.451Z",
//  "updated": "2016-04-29T21:08:10.451Z",
//  "metageneration": "1",
//  "owner": {
//   "entity": "project-owners-999992999999"
//  },
//  "location": "US",
//  "versioning": {
//   "enabled": true
//  },
//  "storageClass": "STANDARD",
//  "etag": "CAE="
// }
// 

CkAuthGoogle_Dispose(gAuth);
CkRest_Dispose(rest);
CkJsonObject_Dispose(jsonReqBody);

end;