method create

class Admin::TestimonialsController < ApplicationController
  before_action :authenticate_user!

# . . .

  def create
    testimonial = Testimonial.new(t_params)

    if testimonial.save
      testimonial = find_testimonial(testimonial.id)
      render json: testimonial, status: :created
    else
      render json: {errors: testimonial.errors}, status: :bad_request
    end
  end

# . . .

  private

  def params_filter
    params.permit :name, :patronymic, :surname, :userpic, :company,
                  :object_photo_1, :object_photo_2, :object_photo_3,
                  :video, :text, :id
  end

  def t_params
    params.each { |param| param = nil if param == "null" }

    safe_params = params_filter
    params = ActionController::Parameters.new(testimonial: safe_params)

    params.require(:testimonial).permit :name, :patronymic, :surname, :userpic, :company,
                                        :object_photo_1, :object_photo_2, :object_photo_3,
                                        :video, :text, :id
  end

# . . .

end