Info Catalog
gnus: Mail Group Commands
gnus: Summary Buffer
gnus: Exiting the Summary Buffer
3.27 Various Summary Stuff ==========================
· Summary Group Information Information oriented commands.
· Searching for Articles Multiple article commands.
· Summary Generation Commands
· Really Various Summary Commands Those pesky non-conformant commands.
‘gnus-summary-display-while-building’
If non-‘nil’, show and update the summary buffer as it’s being
built. If ‘t’, update the buffer after every line is inserted. If
the value is an integer, N, update the display every N lines. The
default is ‘nil’.
‘gnus-summary-display-arrow’
If non-‘nil’, display an arrow in the fringe to indicate the
current article.
‘gnus-summary-mode-hook’
This hook is called when creating a summary mode buffer.
‘gnus-summary-generate-hook’
This is called as the last thing before doing the threading and the
generation of the summary buffer. It’s quite convenient for
customizing the threading variables based on what data the
newsgroup has. This hook is called from the summary buffer after
most summary buffer variables have been set.
‘gnus-summary-prepare-hook’
It is called after the summary buffer has been generated. You
might use it to, for instance, highlight lines or modify the look
of the buffer in some other ungodly manner. I don’t care.
‘gnus-summary-prepared-hook’
A hook called as the very last thing after the summary buffer has
been generated.
‘gnus-summary-ignore-duplicates’
When Gnus discovers two articles that have the same ‘Message-ID’,
it has to do something drastic. No articles are allowed to have
the same ‘Message-ID’, but this may happen when reading mail from
some sources. Gnus allows you to customize what happens with this
variable. If it is ‘nil’ (which is the default), Gnus will rename
the ‘Message-ID’ (for display purposes only) and display the
article as any other article. If this variable is ‘t’, it won’t
display the article—it’ll be as if it never existed.
‘gnus-alter-articles-to-read-function’
This function, which takes two parameters (the group name and the
list of articles to be selected), is called to allow the user to
alter the list of articles to be selected.
For instance, the following function adds the list of cached
articles to the list in one particular group:
(defun my-add-cached-articles (group articles)
(if (string= group "some.group")
(append gnus-newsgroup-cached articles)
articles))
‘gnus-newsgroup-variables’
A list of newsgroup (summary buffer) local variables, or cons of
variables and their default expressions to be evalled (when the
default values are not ‘nil’), that should be made global while the
summary buffer is active.
Note: The default expressions will be evaluated (using function
‘eval’) before assignment to the local variable rather than just
assigned to it. If the default expression is the symbol ‘global’,
that symbol will not be evaluated but the global value of the local
variable will be used instead.
These variables can be used to set variables in the group
parameters while still allowing them to affect operations done in
other buffers. For example:
(setq gnus-newsgroup-variables
'(message-use-followup-to
(gnus-visible-headers .
"^From:\\|^Newsgroups:\\|^Subject:\\|^Date:\\|^To:")))
Also 
Group Parameters.