Rails - Oct 2005 - WriteBoard - Compare Revisions - How'd they do that?

I love WriteBoard.  I''m baffled as to how to go about programming  
something that can track revisions the way it does?  Anyone have any  
ideas?  I''m not interested in making a WriteBoard clone, I just like  
knowing how stuff works :)

- Jim

On 10/3/05, Jim Jeffers
<rails-u78NUfcIof50Y1uG8So6J1aTQe2KTcn/@public.gmane.org>
wrote:
> I love WriteBoard.  I''m baffled as to how to go about programming
> something that can track revisions the way it does?  Anyone have any
> ideas?  I''m not interested in making a WriteBoard clone, I just
like
> knowing how stuff works :)
It''s "just" a matter of diffing two strings..

Instiki does it like this
http://dev.instiki.org/file/instiki/trunk/lib/diff.rb. I''m guessing
wildly that writeboard uses something derived from this..

or you could create something which outputs and parses the "official
diff format" (http://www.gnu.org/software/diffutils/diffutils.html).
Like so:
http://dev.collaboa.org/repository/changesets/239

Cheers,
JS


--
http://johansorensen.com
http://theexciter.com

On Mon, 2005-10-03 at 11:19 -0700, Jim Jeffers wrote:
> I love WriteBoard.  I''m baffled as to how to go about programming
> something that can track revisions the way it does?  Anyone have any  
> ideas?  I''m not interested in making a WriteBoard clone, I just
like
> knowing how stuff works :)
> 
http://wiki.rubyonrails.com/rails/pages/ActsAsVersioned

Then you could probably use some svn/cvs type diff tool that would
prettify the output into colors. 

Robby

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Just copy the library from here:
http://dev.instiki.org/file/instiki/trunk/lib/diff.rb.

Save it under your railsdir/lib as diff.rb
In your environment.rb add
require ''diff''

To use the method in the controller do something like this:
@diff_results = HTMLDiff.diff(@object1.text_to_compare,
@object2.text_to_compare)

in your view do something like this:
<%= @diff_results %>

If you want to change the look of the results, add this to your stylesheet:

del.diffmod {
 color: #999;
  background-color: #efefef;
}

ins.diffmod {
  background-color: #cfc;
 text-decoration: none;
 color: #000;
}


Hope this helps,

--
Joe Clarke
http://railsplayground.com

On 10/3/05, Jim Jeffers
<rails-u78NUfcIof50Y1uG8So6J1aTQe2KTcn/@public.gmane.org>
wrote:
> I love WriteBoard.  I''m baffled as to how to go about programming
> something that can track revisions the way it does?  Anyone have any
> ideas?  I''m not interested in making a WriteBoard clone, I just
like
> knowing how stuff works :)
>
> - Jim
> _______________________________________________
> Rails mailing list
> Rails-1W37MKcQCpIf0INCOvqR/iCwEArCW2h5@public.gmane.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>

Wow!  Thanks Joe!

- Jim

On Oct 3, 2005, at 1:06 PM, Joe Clarke wrote:
> Just copy the library from here:
> http://dev.instiki.org/file/instiki/trunk/lib/diff.rb.
>
> Save it under your railsdir/lib as diff.rb
> In your environment.rb add
> require ''diff''
>
> To use the method in the controller do something like this:
> @diff_results = HTMLDiff.diff(@object1.text_to_compare,
> @object2.text_to_compare)
>
> in your view do something like this:
> <%= @diff_results %>
>
> If you want to change the look of the results, add this to your  
> stylesheet:
>
> del.diffmod {
>  color: #999;
>   background-color: #efefef;
> }
>
> ins.diffmod {
>   background-color: #cfc;
>  text-decoration: none;
>  color: #000;
> }
>
>
> Hope this helps,
>
> --
> Joe Clarke
> http://railsplayground.com
>
> On 10/3/05, Jim Jeffers
<rails-u78NUfcIof50Y1uG8So6J1aTQe2KTcn/@public.gmane.org> wrote:
>
>> I love WriteBoard.  I''m baffled as to how to go about
programming
>> something that can track revisions the way it does?  Anyone have any
>> ideas?  I''m not interested in making a WriteBoard clone, I
just like
>> knowing how stuff works :)
>>
>> - Jim
>> _______________________________________________
>> Rails mailing list
>> Rails-1W37MKcQCpIf0INCOvqR/iCwEArCW2h5@public.gmane.org
>> http://lists.rubyonrails.org/mailman/listinfo/rails
>>
>>
> _______________________________________________
> Rails mailing list
> Rails-1W37MKcQCpIf0INCOvqR/iCwEArCW2h5@public.gmane.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>
>
>

There''s also a nice Javascript implementation of diff. Here''s
the
source, although I can''t seem to find the author''s example
showing it
at work right now:
http://ejohn.org/files/jsdiff.js
> Wow!  Thanks Joe!
>
> - Jim
>
> On Oct 3, 2005, at 1:06 PM, Joe Clarke wrote:
>
>
>> Just copy the library from here:
>> http://dev.instiki.org/file/instiki/trunk/lib/diff.rb.