sup talk - Jan 2010 - Ruby question: before-add-message.rb and adding multiple labels at once

In order to keep before-add-message.rb readable, I was using one-line
filters like:

    message.add_label "ad apple" if message.from.email =~
/@insideapple.apple.com/
    message.add_label "ad amazon" if message.from.email =~
/promotion.*@amazon.com/
    message.add_label "list sup" if message.subj =~ /\[sup-talk\]/
    message.add_label "list sup-devel" if message.subj =~
/\[sup-devel\]/

That seemed to work, somehow. Only now I realized that message.add_label
in fact only takes a single label as argument.

Is it true that I have to change the above syntax into the much more
verbose:

    if message.subj =~ /\[sup-devel\]/
	message.add_label :list
	message.add_label :"sup-devel"
    end

Removing a message from the inbox ("message.remove_label :inbox")
while
applying a label leads to a similar ''code bloat''.


Also, it took me a while to realize that errors in before-add-message.rb
won''t lead to a visible error message, but that before-add-message.rb
just silently quits.


The examples in http://sup.rubyforge.org/wiki/wiki.pl?Hooks are a very
good start.

Still, perhaps somebody with robust Ruby skills could add in a section
about the exact usage of message.add_label and message.remove_label,
e.g.:

- What''s the difference between "label" and :label?
- Can I use multiple labels in one invocation?
- How about dashes in labels? Is :sup-devel valid, or should I use
  :"sup-devel"?
- How about spaces in label?
- How about "-inbox"? Does it work?



Regards,
    Gregor Hoffleit

Excerpts from Gregor Hoffleit''s message of Wed Jan 13 08:13:18 -0500
2010:
> In order to keep before-add-message.rb readable, I was using one-line
> filters like:
> 
>     message.add_label "ad apple" if message.from.email =~
/@insideapple.apple.com/
>     message.add_label "ad amazon" if message.from.email =~
/promotion.*@amazon.com/
>     message.add_label "list sup" if message.subj =~
/\[sup-talk\]/
>     message.add_label "list sup-devel" if message.subj =~
/\[sup-devel\]/
> 
> That seemed to work, somehow. Only now I realized that message.add_label
> in fact only takes a single label as argument.
> 
> Is it true that I have to change the above syntax into the much more
> verbose:
> 
>     if message.subj =~ /\[sup-devel\]/
>     message.add_label :list
>     message.add_label :"sup-devel"
>     end
> 
> Removing a message from the inbox ("message.remove_label :inbox")
while
> applying a label leads to a similar ''code bloat''.
You could try this:
[:list, :sup-devel].each { |l| message.add_label l } if condition
[:inbox, :unread].each { |l| message.remove_label l } if condition

Or something like this:
case [message.from, message.subj].flatten.to_s
  when /foo/ then
    [:label1, :label2].each { |l| message.add_label l }
    [:inbox, :unread].each { |l| message.remove_label l }
  when /bar/ then
    [:label3, :label4].each { |l| message.add_label l }
    [:inbox, :unread].each { |l| message.remove_label l }
end

Ok. I ended up with

    ([:list,:"sup-devel"].each {|l| message.add_label l};
message.remove_label :inbox) if message.subj =~ /\[sup-devel\]/

May I request a new function "message.edit_labels" that groks the
syntax
of the ''edit labels'' command (cf. multi_edit_labels in
thread-index-mode.rb):

    message.edit_labels "list sup-devel -inbox" if message.subj =~
/\[sup-devel\]/

Comments?

Regards,
    Gregor Hoffleit



* Eric Sherman <hyperbolist at gmail.com> [Mi Jan 13 16:49:00 +0100
2010]
> You could try this:
> [:list, :sup-devel].each { |l| message.add_label l } if condition
> [:inbox, :unread].each { |l| message.remove_label l } if condition
> 
> Or something like this:
> case [message.from, message.subj].flatten.to_s
>   when /foo/ then
>     [:label1, :label2].each { |l| message.add_label l }
>     [:inbox, :unread].each { |l| message.remove_label l }
>   when /bar/ then
>     [:label3, :label4].each { |l| message.add_label l }
>     [:inbox, :unread].each { |l| message.remove_label l }
> end
>
> Excerpts from Gregor Hoffleit''s message of Wed Jan 13 08:13:18
-0500 2010:
> > In order to keep before-add-message.rb readable, I was using one-line
> > filters like:
> > 
> >     message.add_label "ad apple" if message.from.email =~
/@insideapple.apple.com/
> >     message.add_label "ad amazon" if message.from.email =~
/promotion.*@amazon.com/
> >     message.add_label "list sup" if message.subj =~
/\[sup-talk\]/
> >     message.add_label "list sup-devel" if message.subj =~
/\[sup-devel\]/
> > 
> > That seemed to work, somehow. Only now I realized that
message.add_label
> > in fact only takes a single label as argument.
> > 
> > Is it true that I have to change the above syntax into the much more
> > verbose:
> > 
> >     if message.subj =~ /\[sup-devel\]/
> >     message.add_label :list
> >     message.add_label :"sup-devel"
> >     end
> > 
> > Removing a message from the inbox ("message.remove_label
:inbox") while
> > applying a label leads to a similar ''code bloat''.
>

Reformatted excerpts from Gregor Hoffleit''s message of
2010-01-13:
> Still, perhaps somebody with robust Ruby skills could add in a section
> about the exact usage of message.add_label and message.remove_label,
> e.g.:
> 
> - What''s the difference between "label" and :label?
Nothing. Strings get turned into symbols automagically and so both will
add the label :label.
> - Can I use multiple labels in one invocation?
No.
> - How about dashes in labels? Is :sup-devel valid, or should I use
>   :"sup-devel"?
The latter is necessary, but only because of Ruby''s syntax. You can
also
use "sup-devel", of course.
> - How about spaces in label?
Same as with -''s.
> - How about "-inbox"? Does it work?
It will work but will give you weird errors later on down the road as
punishment for being tricky. :)
-- 
William <wmorgan-sup at masanjin.net>