It is nice when there isn't a DB to maintain and users to authenticate. My professor has asked me to convert a recent research project of his that uses Bespin and calculates errors made by users in a code editor as part of his research.

The goal is to convert from MySQL to using HTML5 localStorage completely. Doesn't seem so hard to do, even though digging in his code might take some time.

Question:
I need to store files and state (last placement of cursor and active file). I have already done so by implementing the recommendations in another stackoverflow thread. But would like your input considering how to structure the content to use.

My current solution > Hashmap like solution with javascript objects:

files = {};
// later, saving
files[fileName] = data;

And then storing in localStorage using some recommendations

localStorage.setObject("files", files);
// Note that setObject(key, data) does not exist but is added
// using Storage.prototype.setObject = function() {...

Currently I'm also considering using some type of numeric id. So that names can be changed without any hassle renaming the key in the hashmap. What is your opinion on the way it is solved and would you do it any differently?