Optional Backend Functions Backend Interface Writing New Backends

10.5.2.3: Error Messaging

The backends should use the function nnheader-report to report error conditions---they should not raise errors when they aren't able to perform a request. The first argument to this function is the backend symbol, and the rest are interpreted as arguments to format if there are multiple of them, or just a string if there is one of them. This function must always returns nil.

(nnheader-report 'nnchoke "You did something totally bogus")

(nnheader-report 'nnchoke "Could not request group %s" group)

Gnus, in turn, will call nnheader-get-report when it gets a nil back from a server, and this function returns the most recently reported message for the backend in question. This function takes one argument---the server symbol.

Internally, these functions access backend-status-string, so the nnchoke backend will have its error message stored in nnchoke-status-string.

Optional Backend Functions

Backend Interface

Writing New Backends