More Ideas

This Chapter has provided a brief introduction to Tclkit, Starkits, and Metakit. This should be enough to help you get started creating your own Starkits and using Metakit for persistent storage. You should consult the documentation on the Web for more detailed reference material.

Document Bundles

The Starkit archive includes a number of documentation bundles. For example, mk4dok.kit is a Starkit that contains all the MetaKit documentation. These document bundles are all based on Wikit. It is very easy to create Wiki-style documentation for your application and then bundle it up as a Metakit file. You can load wikit.kit and your .tkd document bundle into your application and use the "local" Wikit interface to display your documentation. For example, the critcl Starkit displays its help with this simple command:

Wikit::init [file join $::starkit::topdir doc critcl.tkd]

Self-Updating Applications

The client in a client-server application is an ideal candidate for a self-updating application. The front-end client is a Starkit with some simple startup logic that connects to a server via HTTP and displays a pretty splash screen. The server, which is often based on TclHttpd, delivers code updates to the client. The client caches the code in the VFS inside the Starkit. The application is maintained on the server, and clients automatically get updated as they are used.

This scenario has the same deployment advantage as browser-based applications: you deploy a "thin-client" to desktops that rarely, if ever, changes and you update the application code on the server. In addition, this application structure lets you create a nice client front-end that uses Tcl/Tk instead of HTML, yet still have the benefit of an easy to manage server-side installation of the application code. This design pattern is being used for a number of large-scale commercial application deployments with considerable success.

A similar system is used with the Starkit archive. If you do:

sdx update tclhttpd.kit

The sdx application contacts the web server running the archive and checks for any updates available for the Starkit. Only the differences are transmitted, so updates are quick, and they are automatically applied to your copy of the Starkit. This should work for all the Starkits in the snapshot of the archive on the CD-ROM.

Simple Installers

In some cases you simply must install a collection of files as part of your application. It is very easy to include those files in the VFS, and then extract them into the local file system the first time your application runs. Or, you can create a traditional "installer" that unpacks the entire application from the Starkit (or Starpack).