Error handling for File Key Provider: what is the best approach?

[mradcliffe]

What is the best approach? Should Key throw an exception or return null? An exception would need to be handled with try/catch by modules that use Key so that the application does not crash, but leaves the possibility for an error message. Returning null is easier (?) for a module to handle, maybe?

[nerdstein]

Which event?

When creating the key, we can do a file_exists within the validation of the plugin.

[mradcliffe]

The return value is null in two cases:

1. file does not exist
2. for whatever reason the key provider does not have a file key method setting.

I was going to write coverage for the null return value, but was not sure if it should be changed to throwing an exception instead.

[nerdstein]

@mradcliffe I think NULL is a good starting point at this juncture. The exception handling makes a ton of sense, but you are correct that it would need to be done within each individual module. NULL is controlled by Key. We could go as far as throw a watchdog message if no key is found. Thoughts?