Accessing link_to from within a controller

Rails
1

Hi all

I want to build up a basic menu system for my application. Each
‘section’ has it’s own left hand menu and I was planning on handling
that by defining a ‘menu’ method within each controller, which I’d
pass (along with any other menus I needed at that point) in an
instance variables called @menus. So I’d get something like

def menu
{:title => ‘Vehicles’,
:items => [
link_to(‘List all’, :action => ‘index’),
link_to(‘Search’, :action => ‘search’),
link_to(‘Do something else’, :action => ‘bang’),
]
}
end

def list
@menus = [self.menu]
end

My application layout looks for @menus and displays the menus in the
left hand side. Problem is I can’t access link_to from my controller
as it’s a helper. The FAQ mentions writing your own helpers within
the controller but in this case I want to access a default helper
from the controller.

Question 1: Why is there this restriction?
Question 2: How do I get around it? :slight_smile:

Many thanks for any suggestions. I’ve got ‘The Book’ so if there are
clues in there I’ve missed I’m happy for page numbers. Or if I am
just doing it the wrong way - educate me as to the right way please.

Many thanks once again

Ian Cottee
Blue Fountain Systems Ltd

2

I’m going to restate my problem as I don’t think I understand what a
helper is anymore. I now know this.

  1. I can’t call link_to from within a controller because it’s a
    helper. OK. Clear.
  2. If I define my menu within a helper, I can call that helper
    directly through my view but not a controller. OK. Clear.
  3. I can call paginate from within a controller - even though it’s a
    helper. Hmmm. Not clear.

So what’s the distinction between paginate and link_to?

Ian

3

Thanks Chris

I took a look but I was trying to avoid creating a partial for each
menu (which I think this method implies). What I ended up doing was
keeping my menu definitions in the controller (which I believe is the
right place for it). It looks something like

def menu
{:title => ‘Vehicles’,
:items => [
{:title => ‘New Vehicle’, :params => {:action => ‘new’}},
{:title => ‘List Vehicles’, :params => {:action => ‘list’}}
]
}
end

def menus
[self.menu]
end

And then in my views I do a <% @menus = controller.menus %>

Finally, my application.rhtml layout looks for @menus to be defined
and does the necessary to render it to the menu format I want.

Many thanks for the feedback

Ian

4

you may want to look at render partials

http://rails.rubyonrails.com/classes/ActionController/Base.html#M000171