Question

I wrote a class library in C# that uses a external XML file to store some data. I use this data (encoded rules) directly in the class library to do some substitutions within a text parser. The rules within the XML:

 <rule>
   <word>h e l l o</word>
   <sub>Hello</sub>
 </rule>

When I share the lib, I also have to share the XML. This is a bug source, at least for me 😉 My question: is there any common way to solve such issues? Should I use app.config instead?

Thanks for any hint and best regards!

Answer 1

As with every external configuration data i can be changed or missing. So your application (or library) has to deal with such circumstances.

This means:

• For every missing value you have a default value (should be declared in your documentation)
• Check every value for correctness (type, range, etc.) (All input is evil!)
• Blame user for invalid config files (error message, etc)
• Implement and document behaviour in error case (abort, crash, use default value, etc)

So it doesn’t matter which way to go, cause it is a user configuration (which means it can be changed by the user) and so you have to check those entries.