CODEWITHSUNDEEP
c#.netapp-configconfiguration-files
e4rthdog
e4rthdog

Reputation: 5233

Writable .config file for all users in application directory?

I need to have a common application settings file and i need it to be editable by the application at runtime.

I don't want to use the build in settings operation by putting "User" in settings scope because it gets saved in users local directory.

On the other hand i cant use the .config with "Application" as i cannot save into this file from within the application.

One might say "Create your own save settings XML file its easy"..Yes probably it is but i wonder what is the solution for a common writable config file with MS build in classes?

Upvotes: 2

Views: 3019

Answers (1)

Richard
Richard

Reputation: 109100

To have data, whatever the format, updateable by all users then all users need to be able to save to whatever container holds that data.

This applies whatever the format, from text file to RDBMS.

The problem with a file that you manage (eg. .config (XML) file) is twofold:

  1. Concurrency.
  2. Access Control.

The ConfigurationManager and associated classes will write to a .exe.config file with applicable declaration of the configuration elements and properties, but the underlying file has to be writeable. You'll need to:

  1. Set an ACL in an installer so all (applicable) users have write access. This means outside the application they can write as well, this is unavoidable as there is no ability to set access control based on application.

  2. Install outside Program Files. UAC virtualises writes to Program Files (so applications assuming all users can write anywhere don't break), but this also means it cannot be used for shared modifiable data.

Concurrency is another problem. What is two users both modify the shared data together? One user will overwrite the others changes unless you implement some locking and reloading on changed.

Consider using a multi-user database for the data instead. They are designed for this kind of thing, Config files are not.

Update (based on comment):

To have a (non-admin) user update a .exe.config in Program Files will still hit UAC virtualisation (ie. any writes will be directed to a per-user location, and not-visible to anyone else).

Easier to use the ConfigurationManager.OpenExeConfiguration(string) method to load a .config from some shared location (eg. in C:\ProgramData1) which has an appropriate ACL. The returned Configuration object has all the capabilities of the implicit load from .exe.config for <appSettings> as well as custom sections, plus access to Save and SaveAs.

1 Of course using correct methods to get actual local path, not hardcoding.

Upvotes: 3

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