Rails - Dec 2005 - Semi-Dynamic table sorting (without AJAX)

In a previous thread some people were interested in ways to sort a 
table.  I mentioned a simple method for doing so by using links in the 
titles.  Having actually tried to implement this strategy, I have come 
across several refinements that I would like to share.

First...

your table view should look like this...

...
<table>
 <tr>
  <th><%= link_to ''Column1'',
:sort=>''column1'' %>
  <th><%= link_to ''Column2'',
:sort=>''column2'' %>
 </tr>
 .....
</table>
...

your ''model'' controller ''list'' action should
look like this....

def list
    sorthash = {"column1"=>"column1, updated_at",
"column2"=>"column2
DESC"}
    sorthash.default = "column1, updated_at"
    sort = params[:sort] || session[:model][:sort]
    session[:model][:sort]=sort
    @model_pages, @models = paginate :model, :per_page => 10, 
:order=>sorthash[sort]
end

=== What this does ==
The view passes a hash key as the :sort parameter.  This gets looked up 
in the sorthash, which returns the actual columns needed to sort.  That 
gets passed to the paginator.

Key features...

* the sort order gets saved in the session, so the view will remember 
the sort order until the user logs off.  Without this, even switching to 
another page will cause the view to forget the sort order.

* by putting the valid sort orders into a hash and defining a default 
sort order, we avoid the risk that a malicious user can inject SQL into 
the paginator.  It also keeps the view code prettier.

* all the sorting is done by the database, so this puts more strain on 
the server.  It also causes a page refresh, which can be annoying.  It 
does not require javascript to work.

A similar technique can be used to ''filter'' the view.

Any comments, feedback, tweaks, etc... would be appreciated.

-- 
Posted via http://www.ruby-forum.com/.

> Any comments, feedback, tweaks, etc... would be appreciated.
I like that implementation... thanks for the snippet. :-)

-- 
Posted via http://www.ruby-forum.com/.

On 4/16/06, Christian Klauser <ch27k89@gmail.com>
wrote:
> > Any comments, feedback, tweaks, etc... would be appreciated.
>
> I like that implementation... thanks for the snippet. :-)
>
> --
> Posted via http://www.ruby-forum.com/.
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> Rails mailing list
> Rails@lists.rubyonrails.org
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>
I tried it a couple months ago and had issues with pagination.

When I went to the second page the sort order was lost.

I did not try to resolve it.  I was a definate newbie at that point.

Greg
--
Greg Freemyer
The Norcross Group
Forensics for the 21st Century

The trick for this method is to store the persistent information in the  
session store so that you can reload it on the next page.

I have since moved to a similar (and cleaner) method that doesn''t use  
the session store as much.  I''ll try to write up an article about this
soon after things settle down at work.

On Monday, April 17, 2006, at 8:25 AM, Greg Freemyer
wrote:
>On 4/16/06, Christian Klauser <ch27k89@gmail.com> wrote:
>> > Any comments, feedback, tweaks, etc... would be appreciated.
>>
>> I like that implementation... thanks for the snippet. :-)
>>
>> --
>> Posted via http://www.ruby-forum.com/.
>> _______________________________________________
>> Rails mailing list
>> Rails@lists.rubyonrails.org
>> http://lists.rubyonrails.org/mailman/listinfo/rails
>>
>
>I tried it a couple months ago and had issues with pagination.
>
>When I went to the second page the sort order was lost.
>
>I did not try to resolve it.  I was a definate newbie at that point.
>
>Greg
>--
>Greg Freemyer
>The Norcross Group
>Forensics for the 21st Century
>_______________________________________________
>Rails mailing list
>Rails@lists.rubyonrails.org
>http://lists.rubyonrails.org/mailman/listinfo/rails

_Kevin

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