Helpers -- Problem using one

Rails
1

Hi All,

I’ve got a view “app\views\home\start…rhtml” that invokes a partial
template with:

< %= render :partial => “customer/list” % >

(spaces inserted between % and its associated angle bracket here and in
the
following code).

The partial view “app\views\customer_list.rhtml” creates a link with
the
code:

< %= link_to(c.name,

:controller => ‘customer’,

:action => ‘show’,

:id => c.id)

% >

I’d like to replace the code in the partial view with a one-line helper:

< %= link_to_customer(c) % >

and define the helper in the module in “app\helpers\customer_helper.rb”
with:

def link_to_customer(c)

link_to(c.name,

  controller => 'customer',

  action => 'show',

  id => c.id)

end

When I tried this, I got:

undefined method `link_to_customer’ for #<#Class:0x3cb2710:0x3cb2278>

Any ideas of a way to get this going?

Thanks in advance,

Richard

Env.: WinXP-Pro/SP2, MS VisualStudio.NET Eclipse 3.1.2
Ruby 1.8.2-15 Rails 1.1.4 Java JDK 1.5.0_06

2

Richard L. wrote:

I’ve got a view “app\views\home\start…rhtml” that invokes a partial
template with:
< %= render :partial => “customer/list” % >
undefined method `link_to_customer’ for #<#Class:0x3cb2710:0x3cb2278>

I’m assuming you are calling this partial while in the home controller
(or a controller other than the customer controller). Your
link_to_customer helper method is not mixed into the home controller,
and is therefore not available. You have some choices:

  1. Mix-in the customer helper methods into your other controller with
    ‘helper’:

helper CustomerHelper

  1. Move your link_to_customer definition to application_helper.rb so it
    will be available to all controllers/views.
3

Hi Curtis,

Great explanation!! Especially the alternative options!!

Thanks a lot.
Richard

4

Richard wrote:

Hi Curtis,

Woops. I’m not out of the woods yet.

Your link_to usage from above was:

def link_to_customer©
link_to(c.name,
controller => ‘customer’,
action => ‘show’,
id => c.id)
end

but should be:

def link_to_customer©
link_to(c.name, {:controller => ‘customer’,
:action => ‘show’,
:id => c.id})
end

5

Hi Curtis,

Thanks again. My excuse (we always need one when we screw up, don’t
we), is that I’m a Ruby and Rails newbie. So I’m insufficiently
sensitive to those pesky little colons.

Incidentally, I copied the code I started with from somewhere (but
missed the colons), and that source didn’t use any braces to form the
hash. So I left them out to see whether it would work without them,
wish it did.

I infer from this success that the link_to method’s prototype requires
a hash and the Ruby interpreter accepts the hash-like elements as
components of the needed hash. Just a theory. No need to spend any more
time on me.

Again, thank you very much for pushing me along.

Best wishes,
Richard

6

Hi Curtis,

Woops. I’m not out of the woods yet.

I’m assuming you are calling this partial while in the home controller
Right.

  1. Move your link_to_customer definition to application_helper.rb so it
    will be available to all controllers/views.
    Chose this option, definition same as before.

Substituted my helper invocation in app\views\customer_list.rhtml
(line 12) and got error messages (looks like it’s looking for ‘show’
in home rather than customer folder):

NameError in Home#start

Showing app/views/customer/_list.rhtml where line #12 raised:

undefined local variable or method `action’ for
#<#Class:0x3cd7520:0x3cd7418>

Extracted source (around line #12):

9: <% @customers.each do |c| %>
10:


11:
12: <%= link_to_customer© %>
13:
14: <%= c.balance %>
15: <%= c.last_issue_dt %>

Maybe I have to shift to the other option. I thought I’d wait to see
if you had an approach to make the chosen option work. Maybe it’s not
worth wasting your time on it.

Best wishes,
Richard