Delphi ActiveX

Call a JavaScript Function Returning an Array

See more JavaScript Examples

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

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Integer;
sbScript: TChilkatStringBuilder;
js: TChilkatJs;
result: TChilkatJsonObject;
funcCall: TChilkatJsonObject;
count: Integer;
i: Integer;

begin
success := 0;

// ----------------------------------------------------------------------------------
// The Javascript functions called in this example are shown at the bottom of this page.
// -----------------------------------------------------------------------------------

sbScript := TChilkatStringBuilder.Create(Self);
success := sbScript.LoadFile('js_function_returning_array.js','utf-8');
if (success = 0) then
  begin
    Memo1.Lines.Add(sbScript.LastErrorText);
    Exit;
  end;

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 each function

funcCall := TChilkatJsonObject.Create(Self);

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

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

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": "array",
//   "value": [
//     "Monday",
//     "Tuesday",
//     "Wednesday",
//     "Thursday",
//     "Friday"
//   ]
// }

// Access each array value..
count := result.SizeOfArray('value');
i := 0;
while i < count do
  begin
    result.I := i;
    Memo1.Lines.Add(result.StringOf('value[i]'));
    i := i + 1;
  end;

// ------------------------------------------------------------------------------
// Call the getRange(start,end) function

funcCall.Clear();
funcCall.UpdateString('name','getRange');
funcCall.UpdateInt('args[0]',14);
funcCall.UpdateInt('args[1]',21);
success := js.CallFunction(funcCall.ControlInterface,result.ControlInterface);
Memo1.Lines.Add(result.Emit());

// Output:
// {
//   "type": "array",
//   "value": [
//     14,
//     15,
//     16,
//     17,
//     18,
//     19,
//     20,
//     21
//   ]
// }

count := result.SizeOfArray('value');
i := 0;
while i < count do
  begin
    result.I := i;
    Memo1.Lines.Add(IntToStr(result.IntOf('value[i]')));
    i := i + 1;
  end;

// ------------------------------------------------------------------------------
// Call the getEmployees() function

funcCall.Clear();
funcCall.UpdateString('name','getEmployees');
success := js.CallFunction(funcCall.ControlInterface,result.ControlInterface);
Memo1.Lines.Add(result.Emit());

// Output:
// {
//   "type": "array",
//   "value": [
//     {
//       "id": 101,
//       "name": "Alice",
//       "role": "Dev"
//     },
//     {
//       "id": 102,
//       "name": "Bob",
//       "role": "Manager"
//     }
//   ]
// }

count := result.SizeOfArray('value');
i := 0;
while i < count do
  begin
    result.I := i;
    Memo1.Lines.Add('name: ' + result.StringOf('value[i].name'));
    Memo1.Lines.Add('role: ' + result.StringOf('value[i].role'));
    Memo1.Lines.Add('id: ' + IntToStr(result.IntOf('value[i].id')));
    Memo1.Lines.Add('');
    i := i + 1;
  end;
end;