Multiple CRUD operations on a page

company.html.erb

<!-- Create -->
<%= form_for @department do |f| %>
<p>
	<%= f.label :name, 'Department Name' %>
	<%= f.text_field :name %>
</p>
<p>
	<%= f.label :parent %>
	<% department_array = @departments.all.map { |department| [department.name, department.name] } %>
	<%= f.select :parent, options_for_select([['no parent', '']] + department_array) %>
</p>
<%= f.submit 'Add Department', class: 'btn-std' %>
<% end %>

<!-- In the same file for updtate -->
<%= form_for @department do |f| %>
<%= f.label 'Department Name' %>
<%= f.text_field :name, value: "#{department.name}" %>
<%= f.label :Parent %>
<% department_array = @departments.all.map { |dept| [dept.name, dept.name] } %>
<%= f.select :parent, options_for_select([['no parent', '']] + department_array, "#{department.parent}") %>
<%= f.submit :update, class: 'btn-edit' %>
<% end %>

dashboard_controller.rb

class DashboardController < ApplicationController
  before_action :require_login
  before_filter :init

  def index
    @departments.each do |department|
      childfetch = Department.where(parent: "#{department.name}").select('name')
      instance_variable_set("@#{department.name}Children".gsub(' ','_'), childfetch.map { |child| "#{child.name}" }.join(',') )
    end
  end
  def attendance

  end
  def preferences

  end
  def company
    @department = Department.new
    @allDepartments = Department.all
    #render text: 'foo' and return
  end

  private

  def require_login
    unless session[:user_id].present?
      redirect_to root_url
    end
  end
  def init
    @departments = Department.where(parent: '')
  end
end

departments_controller.rb

class DepartmentsController < ApplicationController
  def index
  end
  def create
  	@department = Department.new(department_params)
  	if @department.save
  		redirect_to :back, notice: 'Department created'
  	else
  		redirect_to dashboard_path
  	end
  end
  def edit
  end
  def update
    @department = Department.new(department_params)
    # update should come here
    render text: @department and return
  end
  def destroy
  end

  private

  def department_params
  	params.require(:department).permit(:name, :parent)
  end
end