I have a large application; lots of forms, multiple dynamic DLLs, etc. I
also have, in the appliation, a general 'Preferences' class object (which is
in itself a separate DLL, and I just include a reference to it so I can
instantiate it at the beginning) which stores all my user preferences. I
serialize the data to and from an XML file, thereby saving and restoring the
user preferences with ease. I also have a Preferences form that the user can
select to modify certain preferences themselves, such as colors, etc. (I say
'certain' because I also save non-browsable preference such as window
location, window size, etc)

I have basically two options to work with the preferences class in my
application: (a) When I load the application, instantiate the preferences
class, load it from the XML file, then keep that class in memory,
referencing the properties as needed. I would also need to 'pass' a
reference to this class around since I do load and use dynamic DLLs. Or (b)
Everytime I need to reference or save a preference, I would simply reload
the class from the XML file, make my modification (or read the data), then,
if needed, re-save the file back out to XML.

The advantages of option A is that, in theory, I only have to read the file
once and then write it out once (I say 'in theory' becuase, when the user
loads the preferences panel, I should save anything that had been modified
up to this point, then re-save the preferences once the user closes the
preferences panel so that things are saved properly). However, it can be a
pain passing the references around to everything, especially since I use
dynamically loaded DLLs. Option B has the advantage in that whenever I
deserialize the preferences class I -KNOW- that I have the latest and
greatest preferences settings. The disadvantage is that I have to read and
write (serialize and deserialize) it every time I want to access or store
information into the class object; and I don't know what kind of performance
hit it will take doing this all the time.

Now the question is: What do you think would be the best method of doing
this? A or B? Or is there another way? I've tried to do a combination of the
two, but it is ending up being very complicated trying to keep things in
sync. I can go either way but was just wondering what everyone thought might
be a better (and more OOP) method of doing it.

Thanks in advance.

Tom