如何验证 Rails 中的重叠时间

我有一个Event model具有form时间和to我的日程应用程序中的时间，我想在保存之前验证重叠时间。

我的视图图像如下；

Departure date: Dec 31, 2016

Day1
07:00 - 07:20 event1
10:30 - 11:30 event2
15:40 - 16:10 event3
[add event button]

Day2
08:15 - 09:05 event4
12:08 - 13:04 event5
14:00 - 14:25 event6
[add event button]

[save schedule button]

from时间和to时间可以同时更改和添加。

我想做的是，如果我尝试添加（或更改为），则显示错误07:05 - 07:30 for Day1， 例如，13:50 - 14:30 for Day2等等。

虽然我尝试了一些代码overlap, between, cover并提及这个帖子 or 这个帖子等等，我无法将它们应用到我的代码中。

模式.rb

  create_table "events", force: :cascade do |t|
    t.time     "from"
    t.time     "to"
    t.integer  "room_id"
    ...

  create_table "rooms", force: :cascade do |t|
    t.integer  "schedule_id"
    ...

  create_table "schedules", force: :cascade do |t|
    t.integer  "user_id"
    t.date     "departure_date"
    ...

给出以下内容models:

class Schedule < ActiveRecord::Base
  belongs_to :user
  has_many :rooms, inverse_of: :schedule
  accepts_nested_attributes_for :rooms, allow_destroy: true
  ...

class Room < ActiveRecord::Base
  belongs_to :schedule, inverse_of: :rooms
  has_many :events, inverse_of: :room
  accepts_nested_attributes_for :events, allow_destroy: true
  ...

class Event < ActiveRecord::Base
  belongs_to :room, inverse_of: :events
  has_one :schedule, autosave: false, through: :room
  ...

_schedule_form.html.erb

  <%= render 'shared/error_messages', object: f.object %>
  <%= f.label :title %>
  <%= f.text_field :title, class: 'form-control' %>
  <br>
    <%= f.label :departure_date %>
    <div class="input-group date" id="datetimepicker">
      <%= f.text_field :departure_date, :value => (f.object.departure_date.strftime('%b/%d/%Y') if f.object.departure_date), class: 'form-control' %>
      <span class="input-group-addon">
        <span class="glyphicon glyphicon-calendar"></span>
      </span>
    </div>
  <script type="text/javascript">
    $(function () {
      $('#datetimepicker').datetimepicker({format:'MMM-DD-YYYY'});
    });
  </script>
  <br>
  <div id="room">
    <%= f.simple_fields_for :rooms do |a| %>
      <div id="room_<%= a.object.object_id %>">
        <p class="day-number-element-selector"><b>Day&nbsp;<%= a.index.to_i + 1 %></b></p>

        <%= a.simple_fields_for :events do |e| %>
          <span class="form-inline">
            <p>
              <%= e.input :from, label: false %>&nbsp;&nbsp;&nbsp;-&nbsp;&nbsp;&nbsp;
              <%= e.input :to, label: false %>
            </p>
          </span>
          <%= e.input :title, label: false %>
        <% end %>
      </div>

      <%= a.link_to_add "Add event", :events, data: {target: "#room_#{a.object.object_id}"}, class: "btn btn-primary" %>

      <%= a.input :room %>

    <% end %>
  </div>

如果您能告诉我如何检查和显示错误，我将不胜感激。

EDIT!

还是不行

event.rb

class Event < ActiveRecord::Base
  before_save :assign_date
  belongs_to :room, inverse_of: :events
  has_one :schedule, autosave: false, through: :room
  validate :cannot_overlap_another_event

scope :in_range, -> range {
  where('(\'from\' BETWEEN ? AND ?)', range.first, range.last)
}
scope :exclude_self, -> id { where.not(id: id) }

def cannot_overlap_another_event
  range = Range.new from, to
  overlaps = Event.exclude_self(id).in_range(range)
  overlap_error unless overlaps.empty?
end

def overlap_error
  errors.add(:overlap_error, 'There is already an event scheduled in this hour!')
end

开发日志

....
Started POST "/schedules" for 218.33.213.91 at 2016-04-07 11:44:59 +0000
Processing by SchedulesController#create as HTML
...
      [1m[35m (0.5ms)[0m  begin transaction
      [1m[36m (0.5ms)[0m  [1mSELECT COUNT(*) FROM "events" WHERE ("events"."id" IS NOT NULL) AND (('from' BETWEEN '2016-04-07 07:00:00.000000' AND '2016-04-07 07:20:00.000000'))[0m
      [1m[35m (0.3ms)[0m  SELECT COUNT(*) FROM "events" WHERE ("events"."id" IS NOT NULL) AND (('from' BETWEEN '2016-04-07 07:05:00.000000' AND '2016-04-07 07:30:00.000000'))
      [1m[36mSQL (0.5ms)[0m  [1mINSERT INTO "schedules" ("title", "departure_date", "user_id", "created_at", "updated_at") VALUES (?, ?, ?, ?, ?)[0m  [["title", "test title"], ["departure_date", "2016-04-10"], ["user_id", 1], ["created_at", "2016-04-07 11:45:00.061460"], ["updated_at", "2016-04-07 11:45:00.061460"]]
...

好吧，如果您需要服务器端验证，您可以实现一些custom模型类中的验证器：

validate :cannot_overlap_another_event

接下来你需要自己编写这个方法的代码：

def cannot_overlap_another_event
  range = Range.new from, to
  overlaps = Appointment.exclude_self(id).in_range(range)
  overlap_error unless overlaps.empty?
end

为了解释这段代码的作用，您创建了一个Range反对你的from and to日期。然后它使用辅助范围来排除Event本身并检查该范围内是否有事件。

scope :in_range, -> range {
  where('(from BETWEEN ? AND ?)', range.first, range.last)
}
scope :exclude_self, -> id { where.not(id: id) }

The overlap_error是一种填充模型错误哈希以显示在屏幕上的方法：

def overlap_error
  errors.add(:overlap_error, 'There is already an event scheduled in this hour!')
end