Question

Ive been trying to get this to work for 3 days now. I cant seem to understand why it doesn work. When the user clicks that link_to tag on the view it should execute the csv function in the controller. Instread I get an exception.

---

Here are the relevant files

Controller file: (users_controller.rb)

def csv 

end

(Routes.rb):

resources :users 

View: (show.html.erb)

 <%= link_to 'Click HERE to open file', @user.image.url  %><br/><br/><br/>
 <%= label_tag(:q, "Parse CSV File:") %><br/>
 <%= link_to 'CSV', csv_user_path %>
 <% end %>

When I click on the “link_to ‘CSV’.. tag above. It gives me this exception:

 NameError in Users#show 
 Showing /Users/AM/Documents/RailsWS/bmc_mam/app/views/users/show.html.erb where line #47 raised:
Extracted source (around line #47):

44:         
45:  <%= label_tag(:q, "Parse CSV File:") %><br/>
46:  
47: <%= link_to 'CSV', csv_user_path %>
48:             
49:         
50:         

The browser URL is as follows when the exception occurs:

http://localhost:3000/users/28

Its clearly getting to the function but the URL mapping /routing is clearly messed up. I m wondering how to fix it…..Ive tried several approaches over the past few days, none seem to be working.
This is the closest Ive gotten to making it work as in …

Thanks in advance for your help.

---

After post answer posted below by @Gavin Miller:

I cahnged my routes.rb file to this:

get 'csv' => 'users#csv'
resources :users 

Now Im getting this exception:

NameError in Users#show

Showing /Users/AM/Documents/RailsWS/bmc_mam/app/views/users/show.html.erb where line #47    raised:

undefined local variable or method `csv_user_path' for #<#  <Class:0x00000104e7f6f8>:0x00000103a23c68>

Extracted source (around line #47):

44:         
45:             <%= label_tag(:q, "Parse CSV File:") %><br/>
46:             
47:             <%= link_to 'CSV', csv_user_path %>
48:             
49:         
50:         

Answer 1

Just declaring resources :users is only going to infer the 7 standard RESTful actions¹. if you want csv to be accepted as a route, you’ll have to explicitly define it:

get 'csv' => 'controller#action'

where controller == users and action == csv.

---

Re-addressing the edited question… You’ll need to pass a user object to the csv_user_path function:

<%= link_to 'CSV', csv_user_path(@user) %>

---

It also appears like you’d like the url to be associated with the user, so you can declare it as a member to get a url like: http://localhost:3000/users/28/csv for that result you can use this code:

resources :users do
  member do
    get 'csv'
  end
end

---

¹ RESTful actions are index, new, create, show, edit, update, destroy as seen in Rails Routing Guide