Since JavaScript can use either single or double quotes to delimit literal strings you may need to escape either of these types of quote by preceeding it with a backslash.Īs an example, suppose we need to pass the string He didn't say 'hello' to a JavaScript function. When passing string literal parameters to JavaScript functions you need to be careful to escape any quote characters contained in the string, otherwise the quote will terminate the string prematurely. Assuming the document is fully loaded, we can call foo() with a method similar to this:Įscaping quotes in string literal parameters Assume also that the HTML document defines a JavaScript function named foo() that takes a string and an integer parameter.

Let us assume we have a TWebBrowser control on a form into which an HTML document has been loaded. We need to ensure that a document object is available by first loading the required document into the web browser and waiting for it to finish loading. So, how do we get hold of the window object that exposes the required method? We simply use the parentWindow property of the web browser control's document object. The method's second parameter specifies the script language being used – in our case 'JavaScript'. The first of this method takes a string containing the required function call (complete with actual parameters).

The window object associated with an HTML document exposes a method – execScript – that enables JavaScript to be called. We'll first examine the techniques then we'll look at a case study that changes the font in an HTML document.įinally, thanks to contributions from Christian Sciberras, we will look at how to get the return value from a JavaScript function called from Delphi. On some occasions, when using a TWebBrowser, I've needed to use Delphi to call JavaScript functions contained in the current document.

Webbrowser select option delphi