Undefined method by link_to helper

Question

I need to post through a link tag, however there is a problem with the link helper. Here is my link tag

// doctors.html.erb
<%= link_to "Ekle", [:add_doctor, @patient], method: :post %> 

And my routes.rb

// routes.rb 
get    'patients/:id/doctors' => 'patients#get_doctors'
post   'patients/:id/doctors' => 'patients#add_doctor'

I get the error

undefined method `add_doctor_patient_path' for #<#:0x007fd39283a4b0>

How should I use link helper to get rid of the problem?

Answer 1

This line in your routes.rb shows that you have a get_doctors route that accepts one argument, :id :

get 'patients/:id/doctors' => 'patients#get_doctors'

That means you should use the corresponding path helper, get_doctors_path , and pass it the Patient object:

<%= link_to "Ekle", get_doctors_path(@patient), method: :post %> 

PS Your routes are puzzling, since you could accomplish the same thing by using resourceful routes, as recommended by the Rails Guides , instead of defining your own custom get and post routes, and in so doing save yourself a lot of trouble:

resources :patients do
  resources :doctors
end

This would create eg patient_doctors_path and new_patient_doctor_path path helpers that would automatically route to your DoctorsController#get and DoctorsController#new methods, respectively, and it would enable you to use eg form_for [ @patient, :doctor ] . PatientsController is very much the wrong place to put logic for retrieving and modifying Doctors.

Answer 2

Just add an as: option on the routes.

// routes.rb 
get    'patients/:id/doctors' => 'patients#get_doctors',as: :patient_get_doctor
post   'patients/:id/doctors' => 'patients#add_doctor', as: :patient_add_doctor

Then in the view:

// doctors.html.erb
<%= link_to "Ekle", patient_add_doctor_path(id: @patient.id), method: :post %>