libr-2/app/controllers/api/v1/application_controller.rb

class Api::V1::ApplicationController < ActionController::Base
  include ActionController::Serialization


  skip_before_action :verify_authenticity_token, raise: false

  serialization_scope :view_context
  before_action :current_user!
  before_action :authenticate_user_from_token

  def current_user!
    @current_user = nil
    @current_user = current_user if user_signed_in?
  end

  def user_json(user= current_user)
    {
      user: {
        id: user.id,
        name: user.name,
        email: user.email,
        token: JWT.encode({id: user.id}, 'tuxue', 'HS256')
      }
    }
  end

  def authenticate_user_from_token

    token = request.headers["Authorization"].try(:split, ' ').try(:last)
    begin
      decoded_token = JWT.decode token, 'tuxue', true
      @current_user = User.find(decoded_token[0]['id'])
      return render json: {message: 'Token is not valid'}, status: 401 unless @current_user
    rescue JWT::DecodeError => e
      return render json: {message: 'Token is not valid'}, status: 401
    end

  end

  def fetch_current_user
    auth_token = AuthToken.find_by(value: request.headers["Authorization"].try(:split, ' ').try(:last))
    @current_user = auth_token.user if auth_token
  end

  private

  def load_target_user
    @target_user = User.find_by id: params[:user_id]
    render json: {msg: '不能找到该用户'}, status: 404 unless @target_user
  end

  def load_post
    @target_post = Post.find_by id: params[:post_id] || params[:id]
    render json: {msg: '不能找到该文章'}, status: 404 unless @target_post
  end

end