A draft for a standard for desktop configuration
jamiemcc at blueyonder.co.uk
Tue Sep 13 01:57:39 EEST 2005
Dave Cridland wrote:
> If schemas are local, then a remote configuration server cannot
> provide defaults sourced from them.
It can cause there's a local daemon present. The config system is like a
traditional three tier client server database application where the
clients (think GConf/KConfig) are very very thin, the middleware is a
thicker daemon (which does all the validation and schema handling) and
the backend is just a local database or a remote one or LDAP etc. Its a
tried and tested design that is commonly used in enterprise software
> Personally, I feel that sane defaults should be either generated by
> the application itself in the absence of data (in which case, they're
> only documentation in the schema) or handled by stacking (which
> complicates application installation).
Schema based defaults are only one layer. There should be emergency
fallback values available in any well designed app in case a schema is
> Section 6.1:
> Personally I have a serious problem with validating on the server.
> There are so many pitfalls and security issues here that I'd much
> rather see the application validate. It is always more aware of
> correct values than the server. Invalid values should be ignored,
> replaced with defaults, or whatever else is most suitable for the
> Some cases where server validation fails includes network
> environments where different client hosts have different application
> versions on them.
Server validation is still local (IE on the local daemon). Read and
write validation (types) is done automatically by serialization and
deserialization of the DBUS Variant in the daemon and the backend will
just chew strings. No need to duplicate this functionality in the
client. The Client never accesses the schema directly (perhaps with the
exception of a tool like GConfTool which would read schema descriptions).
Daemon validation is also sensible here because you can have multiple
different clients (GCOnf and KConfig) with potentially different bugs so
it would be wise to do all validation in one common place on the server
anyhow (as you would in any well designed and robust client/server
Mr Jamie McCracken
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