Delphi ActiveX Requires Chilkat v11.4.0+

Call a JavaScript Function Returning an Object

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Demonstrates how to call a JavaScript function that returns an object. Delphi ActiveX

var
success: Integer;
sbScript: TChilkatStringBuilder;
js: TChilkatJs;
result: TChilkatJsonObject;
funcCall: TChilkatJsonObject;

begin
success := 0;

//  This is the JavaScript function we'll call:

//  function getSettings() {
//      return {
//          theme: "dark",
//          notifications: true,
//          version: 1.0
//      };
//  }

sbScript := TChilkatStringBuilder.Create(Self);
sbScript.Append('function getSettings() {');
sbScript.Append('    return {');
sbScript.Append('        theme: "dark",');
sbScript.Append('        notifications: true,');
sbScript.Append('        version: 1.0');
sbScript.Append('    };');
sbScript.Append('}');

js := TChilkatJs.Create(Self);

result := TChilkatJsonObject.Create(Self);
result.EmitCompact := 0;

//  Call Eval to add the function to the context's global object
success := js.Eval(sbScript.ControlInterface,result.ControlInterface);
if (success = 0) then
  begin
    //  Examine the result for an exception.
    Memo1.Lines.Add(result.Emit());

    //  Also examine the LastErrorText.
    Memo1.Lines.Add(js.LastErrorText);
    Exit;
  end;

//  ------------------------------------------------------------------------------
//  Call the function getSettings()

funcCall := TChilkatJsonObject.Create(Self);

//  Create JSON specifying the function name and arguments
//  The function has no arguments, so we only specify the name.

//  {
//    "name": "getSettings",
//  }

funcCall.UpdateString('name','getSettings');

success := js.CallFunction(funcCall.ControlInterface,result.ControlInterface);
if (success = 0) then
  begin
    //  Examine the result for an exception.
    Memo1.Lines.Add(result.Emit());

    //  Also examine the LastErrorText.
    Memo1.Lines.Add(js.LastErrorText);
    Exit;
  end;

Memo1.Lines.Add(result.Emit());

//  Output:
//  {
//    "type": "object",
//    "value": {
//      "theme": "dark",
//      "notifications": true,
//      "version": 1
//    }
//  }

//  Examine the object's members
Memo1.Lines.Add('theme: ' + result.StringOf('value.theme'));
Memo1.Lines.Add('notifications: ' + IntToStr(Ord(result.BoolOf('value.notifications'))));
Memo1.Lines.Add('version: ' + IntToStr(result.IntOf('value.version')));

//  Output:
//  theme: dark
//  notifications: True
//  version: 1