通知公告排序更改

app/controllers/courses_controller.rb

@@ -18,7 +18,7 @@ class CoursesController < ApplicationController
                                                       :left_banner, :top_banner, :apply_to_join_course, :exit_course, :course_groups]
   before_action :set_course, only: [:show, :update, :destroy, :settings, :set_invite_code_halt,
                                     :set_public_or_private, :search_teacher_candidate, :teachers, :apply_teachers,
-                                     :top_banner, :left_banner, :add_teacher_popup, :add_teacher,
+                                     :top_banner, :left_banner, :add_teacher_popup, :add_teacher, :inform_up, :inform_down,
                                      :graduation_group_list, :create_graduation_group, :join_graduation_group,
                                      :course_group_list, :set_course_group, :change_course_admin, :change_course_teacher,
                                      :delete_course_teacher, :teacher_application_review, :students, :all_course_groups,
@@ -41,7 +41,7 @@ class CoursesController < ApplicationController
                                        :set_course_group, :create_group_by_importing_file,
                                        :update_task_position, :tasks_list]
   before_action :teacher_or_admin_allowed, only: [:graduation_group_list, :create_graduation_group, :join_graduation_group,
-                                                  :change_course_teacher, :course_group_list, :change_member_role,
+                                                  :change_course_teacher, :course_group_list, :change_member_role,:inform_up, :inform_down,
                                                   :teacher_application_review, :apply_teachers, :delete_course_teacher]
   before_action :validate_course_name, only: [:create, :update]
   before_action :find_board, only: :board_list
@@ -281,13 +281,43 @@ class CoursesController < ApplicationController
   end
 
   def informs
-    @informs = @course.informs
+    @informs = @course.informs.order("position desc")
+  end
+
+  def inform_up
+    inform = @course.informs.find_by(id: params[:inform_id])
+    next_inform = inform.next_inform
+    ActiveRecord::Base.transaction do
+      if next_inform
+        render_error('已经到达最底部')
+      else
+        inform.update_attribute(:position, (position + 1))
+        next_inform.update_attribute(:position, last_inform.position - 1)
+        render_ok
+      end
+    end
+  end
+
+  def inform_down
+    inform = @course.informs.find_by(id: params[:inform_id])
+    last_inform = inform.last_inform
+    ActiveRecord::Base.transaction do
+      if last_inform
+        render_error('已经到达最顶部')
+      else
+        inform.update_attribute(:position, (position - 1))
+        last_inform.update_attribute(:position, last_inform.position + 1)
+        render_ok
+      end
+    end
+
   end
 
   def new_informs
     inform = Inform.new(container: @course)
     inform.name = params[:name]
     inform.description = params[:description]
+    inform.position = @course.informs.max(:position).to_i + 1
     inform.save!
     normal_status("创建成功")
   end
@@ -300,6 +330,7 @@ class CoursesController < ApplicationController
 
   def delete_informs
     inform = @course.informs.find_by(id: params[:inform_id])
+    @course.informs.where("position > ?", inform.position).update_all("position = position - 1")
     inform.destroy!
     normal_status("删除成功")
   end

app/models/inform.rb

@@ -5,4 +5,13 @@ class Inform < ApplicationRecord
   validates :description, length: { maximum: 5000 }
 
   has_many :attachments, as: :container, dependent: :destroy
+
+  def next_inform
+    Inform.where(position: self.position+1, container_id: self.course_id, container_type: 'Course')
+  end
+
+  def  last_inform
+    Inform.where(position: self.position-1, container_id: self.course_id, container_type: 'Course')
+  end
+
 end

config/routes.rb

@@ -381,6 +381,8 @@ Rails.application.routes.draw do
         get 'work_score'
         get 'act_score'
         get 'statistics'
+        post :inform_up
+        post :inform_down
       end
 
       collection do

db/migrate/20191106094429_add_position_for_informs.rb

@@ -0,0 +1,17 @@
+class AddPositionForInforms < ActiveRecord::Migration[5.2]
+  def change
+    add_column :informs, :position, :integer, :default => 1
+
+    course_ids = Inform.where(container_type: 'Course').pluck(:container_id).uniq
+    courses = Course.where(id: course_ids)
+
+    courses.find_each do |course|
+      next if course.informs.count == 1
+      informs = course.informs.order("created_at asc")
+      informs.each_with_index do |inform, index|
+        inform.update_attribute(:position, index+1)
+      end
+    end
+
+  end
+end