(Delphi DLL) HTTP POST JSON and Parse JSON Response

Demonstrates how to send a JSON POST and then parse the JSON response.

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, Http, HttpResponse, JsonObject;

...

procedure TForm1.Button1Click(Sender: TObject);
var
json: HCkJsonObject;
success: Boolean;
http: HCkHttp;
resp: HCkHttpResponse;
jsonResp: HCkJsonObject;
lifeAmount: PWideChar;
lifeResidualAmount: PWideChar;

begin
json := CkJsonObject_Create();

success := CkJsonObject_LoadFile(json,'qa_data/json/jsonBodyForHttpPost.json');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkJsonObject__lastErrorText(json));
    Exit;
  end;

http := CkHttp_Create();
success := CkHttp_UnlockComponent(http,'Anything for 30-day trial.');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkHttp__lastErrorText(http));
    Exit;
  end;
resp := CkHttp_PostJson2(http,'https://test.something.com/XYZ/API/v1/CreditInsuranceCalculator/CalculatePremiums','application/json',CkJsonObject__emit(json));
if (CkHttp_getLastMethodSuccess(http) <> True) then
  begin
    Memo1.Lines.Add(CkHttp__lastErrorText(http));
    Exit;
  end;

jsonResp := CkJsonObject_Create();
CkJsonObject_Load(jsonResp,CkHttpResponse__bodyStr(resp));

CkJsonObject_putEmitCompact(jsonResp,False);
Memo1.Lines.Add(CkJsonObject__emit(jsonResp));

//  The JSON response to be parsed looks like this:
//  {
//   "LifeAmount": 513.85,
//    "LifeResidualAmount": 123.38,
//    "CriticalIllnessAmount": 0,
//    "CriticalIllnessResidualAmount": 0,
//    "DisabilityAmount": 881.70,
//    "PolicyFee": 0.00,
//    "PolicyFeeSecondary": 0,
//    "PolicyFeeHidden": 50.00,
//    "PolicyFeeHiddenSecondary": 0
//  }

//  We can get the floating point numbers as strings.  Then convert to double
//  using the appropriate string-to-double conversion for your programming language.
//  For example, in C++ use atof.  In C# use Convert.ToDouble.
lifeAmount := CkJsonObject__stringOf(jsonResp,'LifeAmount');
lifeResidualAmount := CkJsonObject__stringOf(jsonResp,'LifeResidualAmount');

Memo1.Lines.Add('LifeAmount = ' + lifeAmount);
Memo1.Lines.Add('LifeResidualAmount = ' + lifeResidualAmount);

CkJsonObject_Dispose(json);
CkHttp_Dispose(http);
CkJsonObject_Dispose(jsonResp);

end;