zyjisdog (zyjisdog)

在一个有翻页的页面上，如何实现跳转到其他页面再返回时能回到上次的页码？

zyjisdog — Tue, 08 May 2018 11:44:51 +0800

我用kaminari实现了 ajax 翻页功能，每一页显示 10 个user的名字，每个名字指向他们的profile。我发现每次点击某个user的名字进入他的个人页面，再使用浏览器的返回按钮时，都会退回到user列表的第一页。请问有没有办法可以记住离开列表页面时的页码？

index.js.erb:

$('.paginator').html('<%= j(paginate @users, remote: true) %>');
$('#users').html('<%= j(render @users) %>');

index.html:

<div class="paginator">
  <%= paginate @users, remote: true %>
</div>
<ul class="users" id="users">
  <%= render @users %>
</ul>

有关 has_one 的一个问题

zyjisdog — Sat, 21 Apr 2018 16:44:04 +0800

有两个 model 为 has_one 和 belongs_to 关系：

class User < ApplicationRecord
  has_one :second_review, dependent: :destroy
  ...
end

class SecondReview < ApplicationRecord
  belongs_to :user
  validates :user_id, presence: true, uniqueness: true  
  ...
end

现在使用user.create_second_review!来创建一条关联记录，如果user.second_review已经存在的话，数据库会报错，然后删除旧的记录，但是不会插入新记录：

2.4.0 :036 > user.create_second_review!
   (0.2ms)  BEGIN
  SecondReview Exists (0.3ms)  SELECT  1 AS one FROM `second_reviews` WHERE `second_reviews`.`user_id` = 2 LIMIT 1
   (0.1ms)  ROLLBACK
   (0.1ms)  BEGIN
  SQL (0.2ms)  DELETE FROM `second_reviews` WHERE `second_reviews`.`id` = 12
   (2.7ms)  COMMIT
ActiveRecord::RecordInvalid: 验证失败: User已经被使用
        from (irb):36

如果用 user.build_second_review.save!，同样会删除旧的记录，但是会插入新的记录：

2.4.0 :038 > user.build_second_review.save!
   (0.2ms)  BEGIN
  SQL (0.3ms)  DELETE FROM `second_reviews` WHERE `second_reviews`.`id` = 13
   (2.8ms)  COMMIT
   (0.2ms)  BEGIN
  SecondReview Exists (0.4ms)  SELECT  1 AS one FROM `second_reviews` WHERE `second_reviews`.`user_id` = 2 LIMIT 1
  SQL (0.3ms)  INSERT INTO `second_reviews` (`user_id`, `created_at`, `updated_at`) VALUES (2, '2018-04-21 08:41:17', '2018-04-21 08:41:17')
   (2.1ms)  COMMIT
 => true

如果在 model 中去掉dependent: :destroy，则不论是create还是build.save都不会有这种问题：

2.4.0 :003 > user.create_second_review!
   (0.3ms)  BEGIN
  SecondReview Exists (0.4ms)  SELECT  1 AS one FROM `second_reviews` WHERE `second_reviews`.`user_id` = 2 LIMIT 1
   (0.1ms)  ROLLBACK
   (0.1ms)  BEGIN
  SecondReview Exists (0.4ms)  SELECT  1 AS one FROM `second_reviews` WHERE `second_reviews`.`user_id` IS NULL AND (`second_reviews`.`id` != 22) LIMIT 1
   (0.3ms)  ROLLBACK
ActiveRecord::RecordNotSaved: Failed to remove the existing associated second_review. The record failed to save after its foreign key was set to nil.
        from (irb):3

2.4.0 :004 > user.build_second_review.save!
   (0.4ms)  BEGIN
  SecondReview Exists (0.4ms)  SELECT  1 AS one FROM `second_reviews` WHERE `second_reviews`.`user_id` IS NULL AND (`second_reviews`.`id` != 22) LIMIT 1
   (0.1ms)  ROLLBACK
ActiveRecord::RecordNotSaved: Failed to remove the existing associated second_review. The record failed to save after its foreign key was set to nil.
        from (irb):4

我的问题是： 1、既然 SecondReview 类里已经有 validation，为什么user_id相同的时候依然会执行数据库操作（删掉旧记录）？ 2、为什么create_second_review!方法在删除旧的记录后不会插入新记录？

对于这个问题，如果 Rails 的机制就是这样的，是不是我就只能写诸如@user.create_second_review! if !@user.second_review 这样丑陋的代码？

有没有兼容 Turbolinks 的弹出层插件？

zyjisdog — Fri, 13 Apr 2018 23:33:39 +0800

之前试用了 Layer，发现不能在 turbolinks 5 下很好地工作。。。

现在的问题是： 1、有没有其他好用的弹出层插件？

2、如果没有，是不是应该去掉 turbolinks？

3、如果去掉 turbolinks，是不是有其他的替代方案？

目前项目是 Rails 5.1

rails 4.2.0.rc1 进行 rake db:create 出错

zyjisdog — Fri, 12 Dec 2014 22:41:42 +0800

我是新建的 app:rails new myapp -d postgresql 然后把 database.yml 里 production:username:改成了自己的用户名; 最后 rake db:create，报错: rake aborted! LoadError: cannot load such file -- rails-html-sanitizer /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/actionview-4.2.0.rc1/lib/action_view/helpers/sanitize_helper.rb:3:in require' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/actionview-4.2.0.rc1/lib/action_view/helpers/sanitize_helper.rb:3:in' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/actionview-4.2.0.rc1/lib/action_view/helpers/text_helper.rb:32:in <module:TextHelper>' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/actionview-4.2.0.rc1/lib/action_view/helpers/text_helper.rb:29:inmodule:Helpers' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/actionview-4.2.0.rc1/lib/action_view/helpers/text_helper.rb:6:in <module:ActionView>' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/actionview-4.2.0.rc1/lib/action_view/helpers/text_helper.rb:4:in' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/actionview-4.2.0.rc1/lib/action_view/helpers/form_tag_helper.rb:18:in <module:FormTagHelper>' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/actionview-4.2.0.rc1/lib/action_view/helpers/form_tag_helper.rb:14:inmodule:Helpers' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/actionview-4.2.0.rc1/lib/action_view/helpers/form_tag_helper.rb:8:in <module:ActionView>' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/actionview-4.2.0.rc1/lib/action_view/helpers/form_tag_helper.rb:6:in' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/actionview-4.2.0.rc1/lib/action_view/helpers/form_helper.rb:4:in require' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/actionview-4.2.0.rc1/lib/action_view/helpers/form_helper.rb:4:in' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/actionview-4.2.0.rc1/lib/action_view/helpers.rb:50:in <module:Helpers>' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/actionview-4.2.0.rc1/lib/action_view/helpers.rb:4:inmodule:ActionView' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/actionview-4.2.0.rc1/lib/action_view/helpers.rb:3:in <top (required)>' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/sprockets-rails-2.2.2/lib/sprockets/rails/legacy_asset_tag_helper.rb:7:inmodule:LegacyAssetTagHelper' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/sprockets-rails-2.2.2/lib/sprockets/rails/legacy_asset_tag_helper.rb:6:in <module:Rails>' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/sprockets-rails-2.2.2/lib/sprockets/rails/legacy_asset_tag_helper.rb:4:inmodule:Sprockets' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/sprockets-rails-2.2.2/lib/sprockets/rails/legacy_asset_tag_helper.rb:3:in <top (required)>' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/sprockets-rails-2.2.2/lib/sprockets/rails/helper.rb:45:inrequire' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/sprockets-rails-2.2.2/lib/sprockets/rails/helper.rb:45:in <module:Helper>' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/sprockets-rails-2.2.2/lib/sprockets/rails/helper.rb:7:inmodule:Rails' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/sprockets-rails-2.2.2/lib/sprockets/rails/helper.rb:6:in <module:Sprockets>' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/sprockets-rails-2.2.2/lib/sprockets/rails/helper.rb:5:in' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/sprockets-rails-2.2.2/lib/sprockets/railtie.rb:6:in require' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/sprockets-rails-2.2.2/lib/sprockets/railtie.rb:6:in' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/sass-rails-4.0.5/lib/sass/rails/railtie.rb:1:in require' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/sass-rails-4.0.5/lib/sass/rails/railtie.rb:1:in' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/sass-rails-4.0.5/lib/sass/rails.rb:11:in require' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/sass-rails-4.0.5/lib/sass/rails.rb:11:in' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/sass-rails-4.0.5/lib/sass-rails.rb:1:in require' /Users/CloudL/.rvm/gems/ruby-2.1.5/gems/sass-rails-4.0.5/lib/sass-rails.rb:1:in' /Users/CloudL/.rvm/gems/ruby-2.1.5@global/gems/bundler-1.7.9/lib/bundler/runtime.rb:76:in require' /Users/CloudL/.rvm/gems/ruby-2.1.5@global/gems/bundler-1.7.9/lib/bundler/runtime.rb:76:inblock (2 levels) in require' /Users/CloudL/.rvm/gems/ruby-2.1.5@global/gems/bundler-1.7.9/lib/bundler/runtime.rb:72:in each' /Users/CloudL/.rvm/gems/ruby-2.1.5@global/gems/bundler-1.7.9/lib/bundler/runtime.rb:72:inblock in require' /Users/CloudL/.rvm/gems/ruby-2.1.5@global/gems/bundler-1.7.9/lib/bundler/runtime.rb:61:in each' /Users/CloudL/.rvm/gems/ruby-2.1.5@global/gems/bundler-1.7.9/lib/bundler/runtime.rb:61:inrequire' /Users/CloudL/.rvm/gems/ruby-2.1.5@global/gems/bundler-1.7.9/lib/bundler.rb:134:in require' /Users/CloudL/Documents/RailsProj/myapp/config/application.rb:7:in' /Users/CloudL/Documents/RailsProj/myapp/Rakefile:4:in `' (See full trace by running task with --trace)

请问这是怎么回事....谢谢大家了:)