Rails - May 2008 - Hashes and Regexes and Special Characters

I am rolling my own smiley/emoticon generator.  A lot of this has do
do with my less than stellar knowledge of ruby, so if this is better
asked on a ruby list, let me know and I''ll move along...

I have text based emoticon replacement working fine.  I use a hash to
define the text/image pairs like this...

emotes = {
  :wow => "wow.gif",
  :lol => "lol.gif"
}

I then have a simple regex that goes through the text and plucks out
[:key] and replaces it with an image tag.

The problem is I would also like to do conversion of :) :O :( and
such.  I''m running into trouble setting up my hash like that.

I can''t seem to use special characters like : or ( in a key.  So I
actually made two hashes, one with description/emote_text pairs and
one with description/image pairs like so...

special_keys = {
  :smile => ":)"
  :frown => ":(
}
special_emotes = {
  :smile => "regular_smile.gif"
  :frown => "frown.gif"
}

Then I thought I would regex something like

special_keys.each_value do |key|
text=text.gsub(/#{key}/,"<img
src=#{special_emotes[special_keys.index(#{key})]}>"
end

Now, forgetting for the moment the right side of that regex, which I
don''t know if it will even work or not, the regex is failing because
the '')'' in #{key} is closing the regex early.  So I thought I
would
get smart and escape the special characters in special_keys like so:

special_keys = {
  :smile => ":\)"
}

Which, to my suprise ends up as {:smile=>":)"}

Foo!

About this time I figured I was trying too hard and that there''s
probably something shiny in ruby that will solve this little problem.
Anyone out there an expert hash wrangler?

TIA!
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On 1 May 2008, at 17:19, andrew.ohnstad-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org
wrote:
>
>
> Now, forgetting for the moment the right side of that regex, which I
> don''t know if it will even work or not, the regex is failing
because
> the '')'' in #{key} is closing the regex early.  So I
thought I would
> get smart and escape the special characters in special_keys like so:
>
> special_keys = {
>  :smile => ":\)"
> }
>
> Which, to my suprise ends up as {:smile=>":)"}
>
> Foo!
>
> About this time I figured I was trying too hard and that there''s
> probably something shiny in ruby that will solve this little problem.
> Anyone out there an expert hash wrangler?
I reckon the reason that happens is because in a string, ) is a  
perfectly valid character but \) is an unknown character escape and so  
the \ gets dropped.
You really don''t want to be doing this by hand though, RegExp.quote  
will do that for you.
Lastly you can have a symbol with anything you want in it, but you  
need to say :''here is a weird symbol''

Fred

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Frederic,

Thank you SO much for your help.  I managed to turn the mess of code I
was writing into something very simple and rubyish.

I now have the following in my helper...
============================================unescaped_emotes ={
  :":)" => "smile.gif",
  :":(" => "frown.gif"
}
emotes ={
  :lol => "laugh.gif",
  :wow => "jawdrop.gif"
}

emotes.each_key do |emote|
  text=text.gsub(/\[:#{Regexp.escape(emote.to_s)}\]/,"<img
src\"#{emotes[emote]}\">")
end
unescaped_emotes.each_key do |emote|
  text=text.gsub(/#{Regexp.escape(emote.to_s)/,"<img
src\"#{unescaped_emotes[emote]}\">")
end
return text

=================================
So sweet.

I decided to keep two seperate hashes for the emotes, to make it more
clear and "pretty".  Any key in unescaped_emotes will be replaced as
is, any key in emotes will be replaced if it appears in the text in
the form [:key].

Thanks a ton for your nudge in the right direction.

---A

On May 1, 12:43 pm, Frederick Cheung
<frederick.che...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
> On 1 May 2008, at 17:19,
andrew.ohns...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org wrote:
>
>
>
>
>
>
>
> > Now, forgetting for the moment the right side of that regex, which I
> > don''t know if it will even work or not, the regex is failing
because
> > the '')'' in #{key} is closing the regex early.  So I
thought I would
> > get smart and escape the special characters in special_keys like so:
>
> > special_keys = {
> >  :smile => ":\)"
> > }
>
> > Which, to my suprise ends up as {:smile=>":)"}
>
> > Foo!
>
> > About this time I figured I was trying too hard and that
there''s
> > probably something shiny in ruby that will solve this little problem.
> > Anyone out there an expert hash wrangler?
>
> I reckon the reason that happens is because in a string, ) is a  
> perfectly valid character but \) is an unknown character escape and so  
> the \ gets dropped.
> You really don''t want to be doing this by hand though,
RegExp.quote  
> will do that for you.
> Lastly you can have a symbol with anything you want in it, but you  
> need to say :''here is a weird symbol''
>
> Fred- Hide quoted text -
>
> - Show quoted text -
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