best way to display alternate view of file

[Aurélien Aptel]

Hi,

I'm working on a mode to view network traces. So far I have a function
that takes a trace file name and displays the result of the trace
analysis (throught wireshark cli tool).

I would like to use the regular mechanism (add a cons to the auto-load
list for .pcap files) but I don't actually want to display the raw
file, I want to use my function to show an "alternate" view of the
file.

What's the idiomatic way to do a mode like this in Elisp?