Re: nnimap usage model

[Kevin Greiner <kgreiner@xpediantsolutions.com>]

David Abrahams <dave@boost-consulting.com> writes:

> Kevin Greiner <kgreiner@xpediantsolutions.com> writes:
>
>> David Abrahams <dave@boost-consulting.com> writes:
>>
>>> Thanks for your reply, Kevin
>>>
>>> Kevin Greiner <kgreiner@xpediantsolutions.com> writes:
>>>
>>>> The agent has three faces and a format specifier to highlight articles
>>>> that have NOT been downloaded.  The faces appear by default while the
>>>> format specifier must be added through customization.
>>>
>>> Hmm, I'll see if I can track that down.  Could you elaborate on what
>>> you mean by "appear by default", and where the customization for the
>>> format specifier can be found?
>>
>> The variable gnus-summary-highlight controls how an article is
>> highlighted in the summary.  It contains a list of conditions and
>> faces over which Gnus will iterate to the first true condition
>> then select that face.  If you don't want to use faces to highlight
>> the undownloaded articles, you should customize gnus-summary-highlight
>> to delete the three cons cells that refer to the
>> gnus*undownloaded-face.
>
> Yes, thanks, I understood all that from your previous postings; I
> don't think it really answers my questions, though.  Should I rephrase
> them?  I thought they were fairly precisely worded and I'm not sure I
> can do better.

Well, "appear by default" is handled by the value of gnus-summary-highlight.
As for changing the format specifier, see gnus-undownloaded-mark below.

>
>>>> If you don't like using colors to indicate the undownloaded articles,
>>>> you can customize gnus-summary-highlight.  Just remove the three cons
>>>> cells that refer to gnus*undownloaded-face.
>>>>
>>>> If you want to use +/- markers you can add %O to gnus-summary-line-format.
>>>
>>> I'll consider that as an alternative; it might be preferable.
>>>
>>>> You're the first to describe newly downloaded articles as being marked
>>>> as "ancient".  
>>>
>>> I think I was mis-describing the marks; the face used for ancient
>>> articles looks a lot like the one used for un-downloaded articles on
>>> NTEmacs when you don't use Courier New :(
>>
>> You can change the characters used by customizing
>> gnus-undownloaded-mark and gnus-downloaded-mark.  The +/- were
>> selected for historical reasons.
>
> I understand that; I wasn't using the article marks in my
> summary-line-format; I was just referring to the face (i.e. colors)
> used.

Well, gnus-summary-highlight names the faces being used.  Once you
know the face, you can customize it with M-x customize-face.

>
>>> NOTE: also, I'm not really sure what I'm getting from
>>> gnus-agent-cache.  All I can find in the documentation says "the agent
>>> is also a big cache!"  Can somebody explain what that means?
>>
>> It is an internal switch for temporarily disabling the agent.  You
>> should leave it set to t.  Gnus will bind it to nil as appropriate
>> times.
>
> Boy, that just makes it even more mysterious!

Well, Kai's answer was much better.  It just goes to show that I
should stick to writing code.

>
> The "hate" part of my love-hate relationship with GNUs is mostly due
> to not being able to get a clear and precise understanding of the
> system architecture and consequently, how to make it do what I want.
> I've tried to RTFM, which is imposing enough already.  I'd hate to
> think that the only way to really understand things is to use the
> source, Luke.


Well, Dave, I'm not sure what manual you were using but from the
comments that you've made in this thread, something is wrong with it.
For example, you previously stated that the only documentation you
could find for gnus-agent-cache was "the agent is also a big cache!".
I just browsed the online info pages and found that "the agent is also
a big cache!" appears on '(gnus) Gnus Unplugged' where it is a
navigation link to the '(gnus) Agent as Cache' page.  On that page, I
found the following description:

  When Gnus is plugged, it is not efficient to download headers or
  articles from the server again, if they are already stored in the
  Agent.  So, Gnus normally only downloads headers once, and stores them
  in the Agent.  These headers are later used when generating the
  summary buffer, regardless of whether you are plugged or unplugged.
  Articles are not cached in the Agent by default though (that would
  potentially consume lots of disk space), but if you have already
  downloaded an article into the Agent, Gnus will not download the
  article from the server again but use the locally stored copy instead.
  
  This behaviour can be controlled by `gnus-agent-cache' (*Note Agent
  Variables::).

English is my first language and I admittedly had to read this twice.
However, the last part of the paragraph reiterates a rather concise
description of gnus-agent-cache: "if you have already downloaded an
article into the Agent, Gnus will not download the article from the
server again but use the locally stored copy instead.
  
This behaviour can be controlled by `gnus-agent-cache'"

This page also had a link to the '(gnus) Agent Variables' page where I
found:

`gnus-agent-cache' 
     Variable to control whether use the locally stored NOV and
     articles when plugged, e.g. essentially using the Agent as a
     cache.  The default is non-nil, which means to use the Agent as a
     cache.

Kevin