gnus: Error Messaging
11.7.2.3 Error Messaging
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The back ends 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 back end 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 back end in question. This function takes one
argument—the server symbol.
Internally, these functions access BACK-END‘-status-string’, so the
‘nnchoke’ back end will have its error message stored in
‘nnchoke-status-string’.
Info Catalog
gnus: Optional Back End Functions
gnus: Back End Interface
gnus: Writing New Back Ends