Undefined method when trying to pass through id

Question

I'm trying to pass a project ID from its show page to an employee_projects form where I can display the projects name. The error I'm getting is

undefined local variable or method `project_id' for #<EmployeeProjectsController:0xb8bdd58>. 

employee_project controller:

# GET /employee_projects/new
  def new
    puts params[project_id]
    @project = Project.find(params[:project_id])
    session[:project_id] = @project.id
    @employee_project = EmployeeProject.new 
  end

employee_projects form

  Assign worker for this project <%= project.projectName%><br>

  <div class="field">
    <%= f.label :employee_id %><br>
    <%= f.collection_select :employee_id, Employee.all, :id, :empLastName, :prompt => "Select worker" %>
  </div>

  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

Projects show

<%= button_to "Assign!", new_employee_project_path(project_id: @project.id) , class: "btn btn-primary", :method => :get %> 

Does anyone have any ideas on how to fix this?

Answer 1

In your controller try changing puts params[project_id] to puts params[:project_id] .

params is a Hash so you must refer to its keys with symbols, that is :project_id . project_id is just a variable that has no value assigned to it, hence the error undefined local variable or method 'project_id' for # .

UPDATE ( "Couldn't find Project with 'id'=" fix)

The button in projects' show view is not sending the parameter project_id even though you are passing it to the new_employee_project_path helper (check your url string and you will see it ending at ? with no parameters). To fix it, i recommend using a regular form instead of button_to helper.

So, instead of this line:

<%= button_to "Assign!", new_employee_project_path(project_id: @project.id) , class: "btn btn-primary", :method => :get %>

Try using this form :

<form action="<%= new_employee_project_path %>" method="get">
  <input type="hidden" name="project_id" value="<%= @project.id %>">
  <input type="submit" value="Assign!" class="btn btn-primary">
</form>