Delphi ActiveX

Enable Chilkat Classes in JavaScript

See more JavaScript Examples

To use Chilkat classes in JavaScript, you must first enable them in the host application, as they are disabled by default. Instantiating a disabled class will cause a JavaScript exception. Chilkat classes can be enabled in four local filesystem access modes: sandbox, readOnly, writeOnly, or readWrite. You can also enable all classes in a chosen mode. 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;
sbJavaScript: TChilkatStringBuilder;
js: TChilkatJs;
result: TChilkatJsonObject;

begin
success := 0;

// Chilkat classes within JavaScript are disabled by default.
// An attempt to instantiate a disabled Chilkat class results in a JavaScript exception.

// For example, try the following JavaScript without first enabling the Chilkat class:

// sb = new CkStringBuilder();
// sb.Append('Hello World');
// success = sb.WriteFile('c:/aaworkarea/helloWorld.txt','utf-8',true);

sbJavaScript := TChilkatStringBuilder.Create(Self);
sbJavaScript.Append('sb = new CkStringBuilder(); sb.Append(''Hello World''); success = sb.WriteFile(''c:/aaworkarea/helloWorld.txt'',''utf-8'',true);');

js := TChilkatJs.Create(Self);

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

// Run the script.  This should result in an error because we haven't enabled the Chilkat CkStringBuilder class.
success := js.Eval(sbJavaScript.ControlInterface,result.ControlInterface);
if (success = 0) then
  begin
    // Examine the result for an exception.
    Memo1.Lines.Add(result.Emit());

    // The result contains this:
    // {
    //   "exception": {
    //     "message": "Cannot create the chilkat object because the chilkat class is disabled in JavaScript. Fix by calling SetCkPermission before calling Eval or CallFunction",
    //     "stack": [
    //       {
    //         "func": "CkStringBuilder"
    //       },
    //       {
    //         "func": "<eval>",
    //         "file": "<input>",
    //         "line": 1,
    //         "col": 9
    //       }
    //     ]
    //   }
    // }

  end;

// Enable the Chilkat CkStringBuilder JavaScript class for readWrite
js.SetCkPermission('CkStringBuilder','readWrite');
// The script should work now...
success := js.Eval(sbJavaScript.ControlInterface,result.ControlInterface);
Memo1.Lines.Add('success = ' + IntToStr(Ord(success)));

// If the CkStringBuilder class is enabled for readOnly or sandbox, then it will fail.
//   - Chilkat methods that could directly or indirectly write to the filesystem require writeOnly or readWrite access.
//   - Chilkat methods that read the local filesystem require readOnly or readWrite access.
//   - Chilkat methods that don't interact with the local filesystem work in any mode including sandbox.
js.SetCkPermission('CkStringBuilder','readOnly');
success := js.Eval(sbJavaScript.ControlInterface,result.ControlInterface);
if (success = 0) then
  begin
    // Examine the result for an exception.
    Memo1.Lines.Add(result.Emit());

    // {
    //   "exception": {
    //     "message": "failed because this Chilkat method requires the writeOnly or readWrite permission",
    //     "stack": [
    //       {
    //         "func": "WriteFile"
    //       },
    //       {
    //         "func": "<eval>",
    //         "file": "<input>",
    //         "line": 1,
    //         "col": 67
    //       }
    //     ]
    //   }
    // }
  end;
end;