My controller is -persistently- sending wrong params[:id] in Rails?! - ruby-on-rails

Question

I'm new to Ruby on Rails & to web programming.
In my application I have two models; Directorate which has_many :users, and User which belongs_to :directorate.
When creating a new user, I use <%= f.collection_select(:directorate_id,Directorate.all, :id, :name) %> in the new.html.erb form to assign the new user to specific directorate. However, I want to build a user-friendly interface for the dba that lists all directorates; and listing all users beside each directorate, with a link to assign any user to a specific directorate.
What I did is the following:
In Directorate model, I defined the following function:
def assign_user!(user)
user.update_attributes(directorate_id: #directorate)
end
and in the directorates controller, I defined the following action:
def assign_user
#directorate = params[:directorate]
assign_user! params[:user]
redirect_to directorates_url
end
Now, directorates/index.html.erb contains the following:
<h1>Listing directorates</h1>
<table>
<tr>
<th>Name</th>
<th>Info</th>
</tr>
<% #directorates.each do |directorate| %>
<tr>
<td><%= directorate.name %></td>
<td><%= directorate.info %></td>
<td><%= link_to 'Show', directorate %></td>
<td><%= link_to 'Edit', edit_directorate_path(directorate) %></td>
<td><%= link_to 'Destroy', directorate, confirm: 'Are you sure?', method: :delete %></td>
<%= #directorate = directorate%>
<%= render 'users_form' %>
</tr>
<% end %>
</table>
<br />
<%= link_to 'New Directorate', new_directorate_path %>
and, -users_form.html.erb contains the following form (which is supposed to list all users beside each directorate, with a link to assign any user to a certain directorate):
<h1>Listing Users</h1>
<table>
<tr>
<th>User Name</th>
</tr>
<% #users.each do |user| %>
<tr>
<td><%= user.username %></td>
<td><%= link_to 'Assign to Current Directorate', {controller: 'directorates', action: 'assign_user', directorate: #directorate, user: user}, :method => :put %></td>
</tr>
<% end %>
</table>
<br />
Here is the problem, when listing directorates & click on the 'Assign to Current Directorate' I receive the following error:
http://127.0.0.1:3000/directorates/assign_user?directorate=4&user=5
ActiveRecord::RecordNotFound in DirectoratesController#update
Couldn't find Directorate with id=assign_user
Rails.root: /home/ehab/sites/IAMS
Application Trace | Framework Trace | Full Trace
app/controllers/directorates_controller.rb:61:in `update'
Request
Parameters:
{"_method"=>"put",
"authenticity_token"=>"L5tz3hv2IW0meE79qUq0/tjfGKwDlpC23hOeAWtmTvk=",
"directorate"=>"4",
"user"=>"5",
"id"=>"assign_user"}
It's clear that the params is submitting "id"=>"assign_user" which I don't want, what i want is "id"=>"directorate.id" (4 in the above example). What shall I do to fix this issue?!

Answer 1

first of all your routes should say that assign_user is a member method on a certain directorate object:
resources :directorates do
member do
put :assign_user
end
end
second you say you define assign_user! in Directorate model and assign_user in DirectoratesController but both methods imply that they share same object state like instance variable #directorate which is not true
your controller method assign_user should look vaguely like
def assign_user
#directorate = Directorate.find params[:id]
#user = User.find params[:user_id]
#directorate.assign_user! #user
end
and model method should look like
def assign_user!(user)
user.update_attributes(directorate_id: self.id)
end
and even that i would switch around to instead of telling Directorate to change user's attributes you would tell User to assign itself to whatever controller wants.
and the final bit is your link that assigns user to directorate:
link_to 'Assign to Current Directorate',
assign_user_directorates_path(#directorate, :user_id => user)
0 lines of code above were tested for even syntactical correctness, DO NOT copy-paste, read and understand