osem/app/controllers/admin/contacts_controller.rb

module Admin
  class ContactsController < ApplicationController
    before_action :set_conference
    before_action :set_contact, only: [:show, :edit, :update, :destroy]

    # GET /:conference/contact
    def show
    end

    # GET /:conference/contact/edit
    def edit
    end

    # PATCH/PUT /:conference/contact
    def update
      if @contact.update(contact_params)
        redirect_to admin_conference_contact_path, notice: 'Contact details were successfully updated.'
      else
        render :edit
      end
    end

    # DELETE /:conference/contact
    def destroy
      @contact.destroy
      redirect_to admin_conference_contacts_url, notice: 'Contact details were successfully destroyed.'
    end

    private

      # Use callbacks to share common setup or constraints between actions.
      def set_contact
        @contact = @conference.contact
      end

      def set_conference
        @conference = Conference.find_by(short_title: params[:conference_id])
      end

      # Only allow a trusted parameter "white list" through.
      def contact_params
        # params.require(:contact).permit(:social_tag, :email, :facebook, :googleplus, :twitter, :instagram, :public)
        params[:contact]
      end
  end
end