Rails - Aug 2006 - What''s the best way to stop repeating this line in my controller?

Hi,

I am trying to follow the "DRY" principle and came across a problem.
I am working on a small ajax task manager, and right now in the index  
page which renders the list, I have (for example, in the Lists  
controller):

def index
@lists = List.find(:all)
end

Now within the controller there''s also a list_add action which is  
called via ajax..

def list_add
if List.create(params[:list])
@lists = List.find(:all)
render(:partial => "listform")
end
end

I need to put the @lists = List.find(:all) in it again so it gets the  
new updated list to render via AJAX like I did in the index action,  
and I have to do this for every action I need...

Is there a way to do this so I can stop repeating myself?  Or am I  
outta luck?

Thanks.

use a :before_filter

at top of your controller:

before_filter :get_list

then add:

private
def get_list
@lists = List.find(:all)
end

now get_list will be called before index, list_add, or any other controller
methods. If you just want it for those two change the top line to:

before_filter :get_list, :only => [:index, :list_add]

you can also use :except => [ ... ]


On 8/17/06, Rob Gabaree <lists@rawb.net> wrote:
>
> Hi,
>
> I am trying to follow the "DRY" principle and came across a
problem.
> I am working on a small ajax task manager, and right now in the index
> page which renders the list, I have (for example, in the Lists
> controller):
>
> def index
> @lists = List.find(:all)
> end
>
> Now within the controller there''s also a list_add action which is
> called via ajax..
>
> def list_add
> if List.create(params[:list])
> @lists = List.find(:all)
> render(:partial => "listform")
> end
> end
>
> I need to put the @lists = List.find(:all) in it again so it gets the
> new updated list to render via AJAX like I did in the index action,
> and I have to do this for every action I need...
>
> Is there a way to do this so I can stop repeating myself?  Or am I
> outta luck?
>
> Thanks.
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>


-- 
"Impossible is nothing."
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I don''t think the before_filter will work if you need
to have the action reflect the List.create step.  What
about
def list_add
if List.create(params[:list])
index
render(:partial => "listform")
end
?

Cheers,
B Gates


I am trying to follow the "DRY" principle and came
across a problem.   
I am working on a small ajax task manager, and right
now in the index  
page which renders the list, I have (for example, in
the Lists  
controller):

def index
@lists = List.find(:all)
end

Now within the controller there''s also a list_add
action which is  
called via ajax..

def list_add
if List.create(params[:list])
@lists = List.find(:all)
render(:partial => "listform")
end

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On 8/17/06, B Gates <bmathg@yahoo.com> wrote:
>
> I don''t think the before_filter will work if you need
> to have the action reflect the List.create step.  What
> about
> def list_add
> if List.create(params[:list])
> index
> render(:partial => "listform")
> end
>
>
>
You''re right; I hadn''t looked that carefully at your list_add
function.
However, if what you''re trying to do is use ajax to add an item to a
task
list on a page, then you shouldn''t need to repopulate the your @lists
collection.

Instead your listform partial should contain the view for a single record.
The index view would iterate through record set and show the partial for
each one.

So what you should do is:

def index
@lists = List.find(:all)
end

def list_add
if List.create(params[:list])
render(:partial => "listform")
end
end

Then in your index view, you have something like this:

        <% for @list in @lists %>
                <%= render(:partial => ''listform'') %>
        <% end %>

In _listform.rthml you then have the code that displays a single item (which
you refer to as @list; ie, @list.title, etc.)

In fact, you can take it a step further and use RJS. Get rid of the render
line in your list_add method. In the same folder as your index.rhtml, create
a file called list_add.rjs. Your list_add method will automatically look for
such a file and execute it if found. Add the following line to your
list_add.rjs file:

page.insert_html :bottom, ''id-of-your-task-div-or-table'',
:partial =>
''listform''

This will add a new instance of your listform partial at the end of your
list.

-- 
"Impossible is nothing."
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