Part XI

COM Scripting and Dynamic HTML

Microsoft endorses a component standard called the Component Object Model, or COM. MysterX is a toolkit for MzScheme that allows you to take off-the-shelf COM components, and use them in Scheme programs. It does not matter what language the components were written in -- the COM standard is a binary-level wiring specification. In theory, COM can work on any kind of computer, but in practice, it's restricted to computers running Windows. A nice feature of MysterX is that you can place many COM components inside of windows containing Dynamic HTML, or DHTML. DHTML is just HTML that can change while your program runs. You change the HTML by executing pieces of Scheme code.

1  Installing MysterX

To install MysterX, download the file mysterx.plt from the Web site You can choose to ``execute'' this file, which will automatically run the setup program. Alternatively, save the file, and then either (1) drag-and-drop the file on the "Setup PLT.exe" program (located in the main PLT directory) using Windows Explorer, or (2) run "Setup PLT.exe" with mysterx.plt as an argument.

During installation, you should get two dialog boxes indicating that registration of the files myspage.dll and myssink.dll has succeeded. Click on the "OK" button in the dialog boxes to dismiss them.