gnus: Agent Visuals
6.9.4 Agent Visuals
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If you open a summary while unplugged and, Gnus knows from the group’s
active range that there are more articles than the headers currently
stored in the Agent, you may see some articles whose subject looks
something like ‘[Undownloaded article #####]’. These are placeholders
for the missing headers. Aside from setting a mark, there is not much
that can be done with one of these placeholders. When Gnus finally gets
a chance to fetch the group’s headers, the placeholders will
automatically be replaced by the actual headers. You can configure the
summary buffer’s maneuvering to skip over the placeholders if you care
(See ‘gnus-auto-goto-ignores’).
While it may be obvious to all, the only headers and articles
available while unplugged are those headers and articles that were
fetched into the Agent while previously plugged. To put it another way,
“If you forget to fetch something while plugged, you might have a less
than satisfying unplugged session”. For this reason, the Agent adds two
visual effects to your summary buffer. These effects display the
download status of each article so that you always know which articles
will be available when unplugged.
The first visual effect is the ‘%O’ spec. If you customize
‘gnus-summary-line-format’ to include this specifier, you will add a
single character field that indicates an article’s download status.
Articles that have been fetched into either the Agent or the Cache, will
display ‘gnus-downloaded-mark’ (defaults to ‘+’). All other articles
will display ‘gnus-undownloaded-mark’ (defaults to ‘-’). If you open a
group that has not been agentized, a space (‘ ’) will be displayed.
The second visual effect are the undownloaded faces. The faces,
there are three indicating the article’s score (low, normal, high), seem
to result in a love/hate response from many Gnus users. The problem is
that the face selection is controlled by a list of condition tests and
face names (See ‘gnus-summary-highlight’). Each condition is tested in
the order in which it appears in the list so early conditions have
precedence over later conditions. All of this means that, if you tick
an undownloaded article, the article will continue to be displayed in
the undownloaded face rather than the ticked face.
If you use the Agent as a cache (to avoid downloading the same
article each time you visit it or to minimize your connection time), the
undownloaded face will probably seem like a good idea. The reason being
that you do all of our work (marking, reading, deleting) with downloaded
articles so the normal faces always appear. For those users using the
agent to improve online performance by caching the NOV database (most
users since 5.10.2), the undownloaded faces may appear to be an
absolutely horrible idea. The issue being that, since none of their
articles have been fetched into the Agent, all of the normal faces will
be obscured by the undownloaded faces.
If you would like to use the undownloaded faces, you must enable the
undownloaded faces by setting the ‘agent-enable-undownloaded-faces’
group parameter to ‘t’. This parameter, like all other agent
parameters, may be set on an Agent Category (
Agent Categories),
DONTPRINTYET a Group Topic (Topic Parameters), or an individual group (*noteDONTPRINTYET a Group Topic (Topic Parameters), or an individual group (
Group Parameters).
The one problem common to all users using the agent is how quickly it
can consume disk space. If you using the agent on many groups, it is
even more difficult to effectively recover disk space. One solution is
the ‘%F’ format available in ‘gnus-group-line-format’. This format will
display the actual disk space used by articles fetched into both the
agent and cache. By knowing which groups use the most space, users know
where to focus their efforts when “agent expiring” articles.
Info Catalog
gnus: Agent Commands
gnus: Gnus Unplugged
gnus: Agent as Cache