How to Execute a JavaScript Code on a TWebBrowser Document

The TWebBrowser Delphi control provides access to the Web browser functionality from your Delphi applications.

Here's how to execute a custom script (JavaScript or VBScript) function on a HTML document loaded in the TWebBrowser control:

uses MSHTML_TLB, SHDocVw;
procedure ExecuteScript(doc: IHTMLDocument2; script: string; language: string) ;
begin
if doc <> nil then
begin
     if doc.parentWindow <> nil then
       doc.parentWindow.ExecScript(script, Olevariant(language)) ;
end;
end;

Usage (in some Button OnClick event handler, for example):

var
   script : string;
begin
//locate the first element with ID attribute = "main" and show its tag
   script := 'var elemMain = document.getElementById("main") ; if (elemMain != null) { alert(elemMain.tagName) ; }';
   ExecuteScript(EmbeddedWB1.Document as IHTMLDocument2, script, 'javascript')
end;

Note: More TWebBrowser Tips'n'Tricks!