我是rails的新手，并试图通过创建应用程序来学习框架。我正在尝试的是在不使用POST数据的情况下将记录保存到数据库。所有的魔法应该在点击后续链接后完成。
我的代码：
def create
@user = User.find(session[:user_id])
@follower = Follower.new(followers: @user.username, following: params[:format])
if @follower.save
redirect_to @user, notice: "You are now following #{params[:format]}"
end
end
模特：
class Follower < ActiveRecord::Base
validates :follower, presence: true
validates :following, presence: true
end
我得到的错误：
NoMethodError in FollowersController#create
undefined method `follower' for #<Follower:0x007fe382c248c8>
堆栈追踪：
activemodel (4.0.3) lib/active_model/attribute_methods.rb:439:in `method_missing'
activerecord (4.0.3) lib/active_record/attribute_methods.rb:155:in `method_missing'
activemodel (4.0.3) lib/active_model/validator.rb:151:in `block in validate'
activemodel (4.0.3) lib/active_model/validator.rb:150:in `each'
activemodel (4.0.3) lib/active_model/validator.rb:150:in `validate'
activerecord (4.0.3) lib/active_record/validations/presence.rb:5:in `validate'
activesupport (4.0.3) lib/active_support/callbacks.rb:283:in `_callback_before_447'
activesupport (4.0.3) lib/active_support/callbacks.rb:377:in `_run__290785027829406180__validate__callbacks'
activesupport (4.0.3) lib/active_support/callbacks.rb:80:in `run_callbacks'
activemodel (4.0.3) lib/active_model/validations.rb:373:in `run_validations!'
activemodel (4.0.3) lib/active_model/validations/callbacks.rb:106:in `block in run_validations!'
activesupport (4.0.3) lib/active_support/callbacks.rb:373:in `_run__290785027829406180__validation__callbacks'
activesupport (4.0.3) lib/active_support/callbacks.rb:80:in `run_callbacks'
activemodel (4.0.3) lib/active_model/validations/callbacks.rb:106:in `run_validations!'
activemodel (4.0.3) lib/active_model/validations.rb:314:in `valid?'
activerecord (4.0.3) lib/active_record/validations.rb:70:in `valid?'
activerecord (4.0.3) lib/active_record/validations.rb:77:in `perform_validations'
activerecord (4.0.3) lib/active_record/validations.rb:51:in `save'
activerecord (4.0.3) lib/active_record/attribute_methods/dirty.rb:32:in `save'
activerecord (4.0.3) lib/active_record/transactions.rb:270:in `block (2 levels) in save'
activerecord (4.0.3) lib/active_record/transactions.rb:326:in `block in with_transaction_returning_status'
activerecord (4.0.3) lib/active_record/connection_adapters/abstract/database_statements.rb:202:in `block in transaction'
activerecord (4.0.3) lib/active_record/connection_adapters/abstract/database_statements.rb:210:in `within_new_transaction'
activerecord (4.0.3) lib/active_record/connection_adapters/abstract/database_statements.rb:202:in `transaction'
activerecord (4.0.3) lib/active_record/transactions.rb:209:in `transaction'
activerecord (4.0.3) lib/active_record/transactions.rb:323:in `with_transaction_returning_status'
activerecord (4.0.3) lib/active_record/transactions.rb:270:in `block in save'
activerecord (4.0.3) lib/active_record/transactions.rb:281:in `rollback_active_record_state!'
activerecord (4.0.3) lib/active_record/transactions.rb:269:in `save'
app/controllers/followers_controller.rb:8:in `create'
actionpack (4.0.3) lib/action_controller/metal/implicit_render.rb:4:in `send_action'
actionpack (4.0.3) lib/abstract_controller/base.rb:189:in `process_action'
actionpack (4.0.3) lib/action_controller/metal/rendering.rb:10:in `process_action'
actionpack (4.0.3) lib/abstract_controller/callbacks.rb:18:in `block in process_action'
activesupport (4.0.3) lib/active_support/callbacks.rb:403:in `_run__3353578329054758817__process_action__callbacks'
activesupport (4.0.3) lib/active_support/callbacks.rb:80:in `run_callbacks'
actionpack (4.0.3) lib/abstract_controller/callbacks.rb:17:in `process_action'
actionpack (4.0.3) lib/action_controller/metal/rescue.rb:29:in `process_action'
actionpack (4.0.3) lib/action_controller/metal/instrumentation.rb:31:in `block in process_action'
activesupport (4.0.3) lib/active_support/notifications.rb:159:in `block in instrument'
activesupport (4.0.3) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (4.0.3) lib/active_support/notifications.rb:159:in `instrument'
actionpack (4.0.3) lib/action_controller/metal/instrumentation.rb:30:in `process_action'
actionpack (4.0.3) lib/action_controller/metal/params_wrapper.rb:245:in `process_action'
activerecord (4.0.3) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
actionpack (4.0.3) lib/abstract_controller/base.rb:136:in `process'
actionpack (4.0.3) lib/abstract_controller/rendering.rb:44:in `process'
actionpack (4.0.3) lib/action_controller/metal.rb:195:in `dispatch'
actionpack (4.0.3) lib/action_controller/metal/rack_delegation.rb:13:in `dispatch'
actionpack (4.0.3) lib/action_controller/metal.rb:231:in `block in action'
actionpack (4.0.3) lib/action_dispatch/routing/route_set.rb:80:in `call'
actionpack (4.0.3) lib/action_dispatch/routing/route_set.rb:80:in `dispatch'
actionpack (4.0.3) lib/action_dispatch/routing/route_set.rb:48:in `call'
actionpack (4.0.3) lib/action_dispatch/journey/router.rb:71:in `block in call'
actionpack (4.0.3) lib/action_dispatch/journey/router.rb:59:in `each'
actionpack (4.0.3) lib/action_dispatch/journey/router.rb:59:in `call'
actionpack (4.0.3) lib/action_dispatch/routing/route_set.rb:680:in `call'
rack (1.5.2) lib/rack/etag.rb:23:in `call'
rack (1.5.2) lib/rack/conditionalget.rb:25:in `call'
rack (1.5.2) lib/rack/head.rb:11:in `call'
actionpack (4.0.3) lib/action_dispatch/middleware/params_parser.rb:27:in `call'
actionpack (4.0.3) lib/action_dispatch/middleware/flash.rb:241:in `call'
rack (1.5.2) lib/rack/session/abstract/id.rb:225:in `context'
rack (1.5.2) lib/rack/session/abstract/id.rb:220:in `call'
actionpack (4.0.3) lib/action_dispatch/middleware/cookies.rb:486:in `call'
activerecord (4.0.3) lib/active_record/query_cache.rb:36:in `call'
activerecord (4.0.3) lib/active_record/connection_adapters/abstract/connection_pool.rb:626:in `call'
activerecord (4.0.3) lib/active_record/migration.rb:369:in `call'
actionpack (4.0.3) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
activesupport (4.0.3) lib/active_support/callbacks.rb:373:in `_run__1226512649512727885__call__callbacks'
activesupport (4.0.3) lib/active_support/callbacks.rb:80:in `run_callbacks'
actionpack (4.0.3) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (4.0.3) lib/action_dispatch/middleware/reloader.rb:64:in `call'
actionpack (4.0.3) lib/action_dispatch/middleware/remote_ip.rb:76:in `call'
actionpack (4.0.3) lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call'
actionpack (4.0.3) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
railties (4.0.3) lib/rails/rack/logger.rb:38:in `call_app'
railties (4.0.3) lib/rails/rack/logger.rb:20:in `block in call'
activesupport (4.0.3) lib/active_support/tagged_logging.rb:67:in `block in tagged'
activesupport (4.0.3) lib/active_support/tagged_logging.rb:25:in `tagged'
activesupport (4.0.3) lib/active_support/tagged_logging.rb:67:in `tagged'
railties (4.0.3) lib/rails/rack/logger.rb:20:in `call'
actionpack (4.0.3) lib/action_dispatch/middleware/request_id.rb:21:in `call'
rack (1.5.2) lib/rack/methodoverride.rb:21:in `call'
rack (1.5.2) lib/rack/runtime.rb:17:in `call'
activesupport (4.0.3) lib/active_support/cache/strategy/local_cache.rb:83:in `call'
rack (1.5.2) lib/rack/lock.rb:17:in `call'
actionpack (4.0.3) lib/action_dispatch/middleware/static.rb:64:in `call'
rack (1.5.2) lib/rack/sendfile.rb:112:in `call'
railties (4.0.3) lib/rails/engine.rb:511:in `call'
railties (4.0.3) lib/rails/application.rb:97:in `call'
rack (1.5.2) lib/rack/lock.rb:17:in `call'
rack (1.5.2) lib/rack/content_length.rb:14:in `call'
rack (1.5.2) lib/rack/handler/webrick.rb:60:in `service'
/Users/bim/.rvm/rubies/ruby-1.9.3-p0/lib/ruby/1.9.1/webrick/httpserver.rb:138:in `service'
/Users/bim/.rvm/rubies/ruby-1.9.3-p0/lib/ruby/1.9.1/webrick/httpserver.rb:94:in `run'
/Users/bim/.rvm/rubies/ruby-1.9.3-p0/lib/ruby/1.9.1/webrick/server.rb:191:in `block in start_thread'
答案 0 :(得分：0)
基于堆栈跟踪和错误，看起来您正在模型中的某处访问follower方法并且它不存在。
检查validations模型中的指定Follower
应该看起来像
validates :followers,.... ## Plural followers
而不是
validates :follower,....