我最近将rails 3.2项目升级到4.0。我已成功通过guides升级我的应用程序。我有一些问题，我不确定我应该去哪个方向，我正在寻求一些帮助。
我在我的模型上使用了很多attr_accessible，我现在根据指南中的建议将其删除。导游说：
Rails 4.0已删除了attr_accessible和attr_protected功能 赞成强参数。您可以使用Protected Attributes gem 为了顺利升级路径。
这个gem使我的应用程序运行，但是当我尝试创建一个新对象（如用户，消息等）时，我收到一个错误。从一些研究来看，这在使用新宝石时似乎很常见。有人建议删除可以解决新对象问题的gem。我这样做但是现在我从我的应用程序中的一些其他宝石中得到了多个错误（是的，我已经将所有宝石升级到最新版本）。这是我得到的错误：
/usr/local/rvm/gems/ruby-2.0.0-p247/gems/activemodel-4.0.0/lib/active_model/deprecated_mass_assignment_security.rb:14:in `attr_accessible': `attr_accessible` is extracted out of Rails into a gem. Please use new recommended protection model for params(strong_parameters) or add `protected_attributes` to your Gemfile to use old one. (RuntimeError)
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/acts-as-messageable-0.4.8/lib/acts-as-messageable/message.rb:8:in `<class:Message>'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/acts-as-messageable-0.4.8/lib/acts-as-messageable/message.rb:4:in `<module:ActsAsMessageable>'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/acts-as-messageable-0.4.8/lib/acts-as-messageable/message.rb:3:in `<top (required)>'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/inflector/methods.rb:228:in `const_get'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/inflector/methods.rb:228:in `block in constantize'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/inflector/methods.rb:224:in `each'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/inflector/methods.rb:224:in `inject'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/inflector/methods.rb:224:in `constantize'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/core_ext/string/inflections.rb:66:in `constantize'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/acts-as-messageable-0.4.8/lib/acts-as-messageable/model.rb:34:in `acts_as_messageable'
from /Users/dave/rails_projects/EquiptMe/app/models/user.rb:14:in `<class:User>'
from /Users/dave/rails_projects/EquiptMe/app/models/user.rb:1:in `<top (required)>'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:423:in `load'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:423:in `block in load_file'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:615:in `new_constants_in'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:422:in `load_file'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:323:in `require_or_load'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:462:in `load_missing_constant'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:183:in `const_missing'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/inflector/methods.rb:226:in `const_get'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/inflector/methods.rb:226:in `block in constantize'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/inflector/methods.rb:224:in `each'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/inflector/methods.rb:224:in `inject'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/inflector/methods.rb:224:in `constantize'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:534:in `get'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:565:in `constantize'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/devise-3.0.1/lib/devise.rb:278:in `get'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/devise-3.0.1/lib/devise/mapping.rb:77:in `to'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/devise-3.0.1/lib/devise/mapping.rb:72:in `modules'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/devise-3.0.1/lib/devise/mapping.rb:89:in `routes'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/devise-3.0.1/lib/devise/mapping.rb:156:in `default_used_route'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/devise-3.0.1/lib/devise/mapping.rb:66:in `initialize'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/devise-3.0.1/lib/devise.rb:312:in `new'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/devise-3.0.1/lib/devise.rb:312:in `add_mapping'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/devise-3.0.1/lib/devise/rails/routes.rb:208:in `block in devise_for'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/devise-3.0.1/lib/devise/rails/routes.rb:207:in `each'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/devise-3.0.1/lib/devise/rails/routes.rb:207:in `devise_for'
from /Users/dave/rails_projects/EquiptMe/config/routes.rb:7:in `block in <top (required)>'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/actionpack-4.0.0/lib/action_dispatch/routing/route_set.rb:316:in `instance_exec'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/actionpack-4.0.0/lib/action_dispatch/routing/route_set.rb:316:in `eval_block'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/actionpack-4.0.0/lib/action_dispatch/routing/route_set.rb:294:in `draw'
from /Users/dave/rails_projects/EquiptMe/config/routes.rb:1:in `<top (required)>'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:222:in `load'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:222:in `block in load'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:213:in `load_dependency'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:222:in `load'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:40:in `block in load_paths'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:40:in `each'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:40:in `load_paths'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:16:in `reload!'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:26:in `block in updater'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/file_update_checker.rb:75:in `call'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/file_update_checker.rb:75:in `execute'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:27:in `updater'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application/routes_reloader.rb:6:in `execute_if_updated'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application/finisher.rb:69:in `block in <module:Finisher>'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/initializable.rb:30:in `instance_exec'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/initializable.rb:30:in `run'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/initializable.rb:55:in `block in run_initializers'
from /usr/local/rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/tsort.rb:150:in `block in tsort_each'
from /usr/local/rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/tsort.rb:183:in `block (2 levels) in each_strongly_connected_component'
from /usr/local/rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/tsort.rb:219:in `each_strongly_connected_component_from'
from /usr/local/rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/tsort.rb:182:in `block in each_strongly_connected_component'
from /usr/local/rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/tsort.rb:180:in `each'
from /usr/local/rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/tsort.rb:180:in `each_strongly_connected_component'
from /usr/local/rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/tsort.rb:148:in `tsort_each'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/initializable.rb:54:in `run_initializers'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/application.rb:215:in `initialize!'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/railtie/configurable.rb:30:in `method_missing'
from /Users/dave/rails_projects/EquiptMe/config/environment.rb:5:in `<top (required)>'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `require'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `block in require'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:213:in `load_dependency'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/dependencies.rb:228:in `require'
from /Users/dave/rails_projects/EquiptMe/config.ru:3:in `block in <main>'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/rack-1.5.2/lib/rack/builder.rb:55:in `instance_eval'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/rack-1.5.2/lib/rack/builder.rb:55:in `initialize'
from /Users/dave/rails_projects/EquiptMe/config.ru:in `new'
from /Users/dave/rails_projects/EquiptMe/config.ru:in `<main>'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/rack-1.5.2/lib/rack/builder.rb:49:in `eval'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/rack-1.5.2/lib/rack/builder.rb:49:in `new_from_string'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/rack-1.5.2/lib/rack/builder.rb:40:in `parse_file'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/rack-1.5.2/lib/rack/server.rb:277:in `build_app_and_options_from_config'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/rack-1.5.2/lib/rack/server.rb:199:in `app'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/commands/server.rb:48:in `app'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/rack-1.5.2/lib/rack/server.rb:314:in `wrapped_app'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/commands/server.rb:75:in `start'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/commands.rb:78:in `block in <top (required)>'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/commands.rb:73:in `tap'
from /usr/local/rvm/gems/ruby-2.0.0-p247/gems/railties-4.0.0/lib/rails/commands.rb:73:in `<top (required)>'
from script/rails:6:in `require'
from script/rails:6:in `<main>'
有人能指出我正确的方向吗？
由于
答案 0 :(得分：1)
我会尝试在Gemfile中使用“act-as-messageable”gem的主分支。看起来自从上次发布以来，已经有一些与Rails 4相关的更新。如果修复它，我会ping作者，看看他们是否会发布新版本。
答案 1 :(得分：0)
最近创建了一个新的gem来帮助从Rails 3升级到Rails 4.我最近使用它并且它使升级过程变得更加容易。
宝石名为wize_upgrader。
这个gem在rails 3模型中使用attr_accessible做的一件事就是将它转换为控制器中的强力参数。
即:(在posts_controller中）
def post_params
params.require(:post).permit(:title, :content, :tag)
end