1

我似乎无法让 CanCan 工作。事实证明，这非常令人沮丧，尤其是当我遵循规则手册并尝试似乎在阳光下所有技巧以使其发挥作用时。

我正在使用 Rails 3.1.2、Devise 2.1.2 和 CanCan 1.6.8。我建立了一个单独的角色模型，正如 RyanB在这里描述的那样。

这是我的代码。

1) 能力.rb

class Ability
  include CanCan::Ability

  def initializer(user)
    user ||= User.new  # For users with no account

    if (user.has_role?(:admin)) || (user.has_role?(:mod))
      can :manage, :all

    elsif user.has_role?(:registered)
      can :read, :all
      can :create, :all

      can :update, Question do |question|
        question.try(:user) == (user || user.has_role?(:admin) || user.has_role?(:mod))
      end

      can :destroy, Question do |question|
        question.try(:user) == (user || user.has_role?(:admin) || user.has_role?(:mod))
      end

    else
      can :read, :all        
    end
  end
end

2）has_role？user.rb 中的定义

def has_role?(role_sym)
  roles.any? { |r| r.name.underscore.to_sym == role_sym }
end

3) 过滤器前的控制器

before_filter :authenticate_user!, :except => :show

load_and_authorize_resource
skip_authorize_resource :only => :show

使用 CanCan 授权任何控制器都会导致所有操作出现相同的错误。

编辑：堆栈跟踪

cancan (1.6.8) lib/cancan/controller_additions.rb:352:in `initialize'
cancan (1.6.8) lib/cancan/controller_additions.rb:352:in `new'
cancan (1.6.8) lib/cancan/controller_additions.rb:352:in `current_ability'
cancan (1.6.8) lib/cancan/controller_resource.rb:207:in `current_ability'
cancan (1.6.8) lib/cancan/controller_resource.rb:77:in `load_collection?'
cancan (1.6.8) lib/cancan/controller_resource.rb:33:in `load_resource'
cancan (1.6.8) lib/cancan/controller_resource.rb:25:in `load_and_authorize_resource'
cancan (1.6.8) lib/cancan/controller_resource.rb:10:in `block in add_before_filter'
activesupport (3.2.1) lib/active_support/callbacks.rb:429:in `_run__458654864__process_action__156152648__callbacks'
activesupport (3.2.1) lib/active_support/callbacks.rb:405:in `__run_callback'
activesupport (3.2.1) lib/active_support/callbacks.rb:385:in `_run_process_action_callbacks'
activesupport (3.2.1) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (3.2.1) lib/abstract_controller/callbacks.rb:17:in `process_action'
actionpack (3.2.1) lib/action_controller/metal/rescue.rb:29:in `process_action'
actionpack (3.2.1) lib/action_controller/metal/instrumentation.rb:30:in `block in process_action'
activesupport (3.2.1) lib/active_support/notifications.rb:123:in `block in instrument'
activesupport (3.2.1) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (3.2.1) lib/active_support/notifications.rb:123:in `instrument'
actionpack (3.2.1) lib/action_controller/metal/instrumentation.rb:29:in `process_action'
actionpack (3.2.1) lib/action_controller/metal/params_wrapper.rb:205:in `process_action'
activerecord (3.2.1) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
actionpack (3.2.1) lib/abstract_controller/base.rb:121:in `process'
actionpack (3.2.1) lib/abstract_controller/rendering.rb:45:in `process'
actionpack (3.2.1) lib/action_controller/metal.rb:203:in `dispatch'
actionpack (3.2.1) lib/action_controller/metal/rack_delegation.rb:14:in `dispatch'
actionpack (3.2.1) lib/action_controller/metal.rb:246:in `block in action'
actionpack (3.2.1) lib/action_dispatch/routing/route_set.rb:66:in `call'
actionpack (3.2.1) lib/action_dispatch/routing/route_set.rb:66:in `dispatch'
actionpack (3.2.1) lib/action_dispatch/routing/route_set.rb:30:in `call'
journey (1.0.4) lib/journey/router.rb:68:in `block in call'
journey (1.0.4) lib/journey/router.rb:56:in `each'
journey (1.0.4) lib/journey/router.rb:56:in `call'
actionpack (3.2.1) lib/action_dispatch/routing/route_set.rb:589:in `call'
warden (1.2.1) lib/warden/manager.rb:35:in `block in call'
warden (1.2.1) lib/warden/manager.rb:34:in `catch'
warden (1.2.1) lib/warden/manager.rb:34:in `call'
actionpack (3.2.1) lib/action_dispatch/middleware/best_standards_support.rb:17:in `call'
rack (1.4.1) lib/rack/etag.rb:23:in `call'
rack (1.4.1) lib/rack/conditionalget.rb:25:in `call'
actionpack (3.2.1) lib/action_dispatch/middleware/head.rb:14:in `call'
actionpack (3.2.1) lib/action_dispatch/middleware/params_parser.rb:21:in `call'
actionpack (3.2.1) lib/action_dispatch/middleware/flash.rb:242:in `call'
rack (1.4.1) lib/rack/session/abstract/id.rb:205:in `context'
rack (1.4.1) lib/rack/session/abstract/id.rb:200:in `call'
actionpack (3.2.1) lib/action_dispatch/middleware/cookies.rb:338:in `call'
activerecord (3.2.1) lib/active_record/query_cache.rb:64:in `call'
activerecord (3.2.1) lib/active_record/connection_adapters/abstract/connection_pool.rb:443:in `call'
actionpack (3.2.1) lib/action_dispatch/middleware/callbacks.rb:28:in `block in call'
activesupport (3.2.1) lib/active_support/callbacks.rb:405:in `_run__446710069__call__461654473__callbacks'
activesupport (3.2.1) lib/active_support/callbacks.rb:405:in `__run_callback'
activesupport (3.2.1) lib/active_support/callbacks.rb:385:in `_run_call_callbacks'
activesupport (3.2.1) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (3.2.1) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (3.2.1) lib/action_dispatch/middleware/reloader.rb:65:in `call'
actionpack (3.2.1) lib/action_dispatch/middleware/remote_ip.rb:31:in `call'
actionpack (3.2.1) lib/action_dispatch/middleware/debug_exceptions.rb:16:in `call'
actionpack (3.2.1) lib/action_dispatch/middleware/show_exceptions.rb:56:in `call'
railties (3.2.1) lib/rails/rack/logger.rb:26:in `call_app'
railties (3.2.1) lib/rails/rack/logger.rb:16:in `call'
actionpack (3.2.1) lib/action_dispatch/middleware/request_id.rb:22:in `call'
rack (1.4.1) lib/rack/methodoverride.rb:21:in `call'
rack (1.4.1) lib/rack/runtime.rb:17:in `call'
activesupport (3.2.1) lib/active_support/cache/strategy/local_cache.rb:72:in `call'
rack (1.4.1) lib/rack/lock.rb:15:in `call'
actionpack (3.2.1) lib/action_dispatch/middleware/static.rb:53:in `call'
railties (3.2.1) lib/rails/engine.rb:479:in `call'
railties (3.2.1) lib/rails/application.rb:220:in `call'
rack (1.4.1) lib/rack/content_length.rb:14:in `call'
railties (3.2.1) lib/rails/rack/log_tailer.rb:14:in `call'
rack (1.4.1) lib/rack/handler/webrick.rb:59:in `service'
/home/administrator/.rvm/rubies/ruby-1.9.3-p125/lib/ruby/1.9.1/webrick/httpserver.rb:138:in `service'
/home/administrator/.rvm/rubies/ruby-1.9.3-p125/lib/ruby/1.9.1/webrick/httpserver.rb:94:in `run'
/home/administrator/.rvm/rubies/ruby-1

.9.3-p125/lib/ruby/1.9.1/webrick/server.rb:191:in `block in start_thread'
4

1 回答 1

2

好吧，看来，我没有遵守规则手册的所有规则。虽然我看不出这怎么可能是个问题。为了让它工作，我删除了我手动创建的能力.rb文件，并使用rails g cancan:ability命令在同一目录中生成相同的文件，并使用相同的代码。现在它就像一个魅力。

于 2012-07-20T06:47:21.130 回答