I do not find any working solution at the moment...
The best attempt so far was to use the following procedure :
It uses JQuery and a small library implementing a "save" and a "load" function. It has to call a jar file in order to work with Opera.
My very simple script works on my computer, using a "normal" Opera, but the "save" and "load" functions do not work anymore on the mobile device. I also tried on my computer with an Opera Mobile emulator, it did not work neither.
Here is a the main part of my code. It succeeds on Opera, but not on Opera Mobile (emulator and mobile device).
Other JQuery queries are working properly on the mobile.
// Run on document load
var $ = jQuery; // local alias
var loc = location.pathname;
var filepath = loc.substr(0,loc.lastIndexOf('/') + 1) + 'test.txt';
var text = $.twFile.load(filepath); // Load the file
Any idea ? Of course, any other method allowing to read/write files would be good too.