The object of the exercise is to create a WWW server which gets it's data from a database. The data consists of a set of node embedded in a Graph. An object called a displayable is pointed at the node in the graph and it is the displayable's job to create a page of HTML based on information reachable from that node. The default displayable just shows the data at that node and a list of pointers to surrounding nodes. Pretty simple. The displayable proc can be part of the URL, so displayables are a mapping from a graph to HTML. Different displayable, different HTML.
KoalaIO is written using tcl-dp, [incr tc] and the msqltcl interface to mSQL. tcl-dp is used to do rpc between the cgi script io and the server ioserver, which maintains context and helps to cach answers.
This paper will show the basic concepts behind KoalaIO and how it can be extended to suit the users requirements. Examples of such extensions will be presented.