Rails 中的 ArgumentError::MailersController#preview 在 Ruby on Rails 中答案

【问题标题】：ArgumentError in Rails::MailersController#preview in Ruby on RailsRails 中的 ArgumentError::MailersController#preview 在 Ruby on Rails 中
【发布时间】：2016-03-02 11:59:15
【问题描述】：

我正在根据 Michael Hartl 的 The Ruby on Rails Tutorial 中给出的教程重置密码

我已经掌握了所有方法，但是password_reset方法存在问题

错误是

wrong number of arguments (0 for 1)

user_mailer.rb

class UserMailer < ApplicationMailer

  def account_activation(user)
    @user = user
    mail to: user.email, subject: "Account activation"
  end

  def password_reset(user)
    @user = user
    mail to: user.email, subject: "Password reset"
  end 
end

这是错误跟踪：

 app/mailers/user_mailer.rb:8:in `password_reset'
    actionpack (4.2.5) lib/abstract_controller/base.rb:198:in `process_action'
    actionpack (4.2.5) lib/abstract_controller/callbacks.rb:20:in `block in process_action'
    activesupport (4.2.5) lib/active_support/callbacks.rb:88:in `__run_callbacks__'
    activesupport (4.2.5) lib/active_support/callbacks.rb:778:in `_run_process_action_callbacks'
    activesupport (4.2.5) lib/active_support/callbacks.rb:81:in `run_callbacks'
    actionpack (4.2.5) lib/abstract_controller/callbacks.rb:19:in `process_action'
    actionpack (4.2.5) lib/abstract_controller/base.rb:137:in `process'
    actionview (4.2.5) lib/action_view/rendering.rb:30:in `process'
    actionmailer (4.2.5) lib/action_mailer/base.rb:596:in `block in process'
    activesupport (4.2.5) lib/active_support/notifications.rb:164:in `block in instrument'
    activesupport (4.2.5) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
    activesupport (4.2.5) lib/active_support/notifications.rb:164:in `instrument'
    actionmailer (4.2.5) lib/action_mailer/base.rb:593:in `process'
    actionmailer (4.2.5) lib/action_mailer/base.rb:584:in `initialize'
    actionmailer (4.2.5) lib/action_mailer/message_delivery.rb:25:in `new'
    actionmailer (4.2.5) lib/action_mailer/message_delivery.rb:25:in `__getobj__'
    /home/mahesh/.rbenv/versions/2.2.3/lib/ruby/2.2.0/delegate.rb:84:in `method_missing'
    railties (4.2.5) lib/rails/mailers_controller.rb:62:in `block in find_preferred_part'
    railties (4.2.5) lib/rails/mailers_controller.rb:61:in `each'
    railties (4.2.5) lib/rails/mailers_controller.rb:61:in `find_preferred_part'
    railties (4.2.5) lib/rails/mailers_controller.rb:34:in `preview'
    actionpack (4.2.5) lib/action_controller/metal/implicit_render.rb:4:in `send_action'
    actionpack (4.2.5) lib/abstract_controller/base.rb:198:in `process_action'
    actionpack (4.2.5) lib/action_controller/metal/rendering.rb:10:in `process_action'
    actionpack (4.2.5) lib/abstract_controller/callbacks.rb:20:in `block in process_action'
    activesupport (4.2.5) lib/active_support/callbacks.rb:117:in `call'
    activesupport (4.2.5) lib/active_support/callbacks.rb:117:in `call'
    activesupport (4.2.5) lib/active_support/callbacks.rb:555:in `block (2 levels) in compile'
    activesupport (4.2.5) lib/active_support/callbacks.rb:505:in `call'
    activesupport (4.2.5) lib/active_support/callbacks.rb:505:in `call'
    activesupport (4.2.5) lib/active_support/callbacks.rb:92:in `__run_callbacks__'
    activesupport (4.2.5) lib/active_support/callbacks.rb:778:in `_run_process_action_callbacks'
    activesupport (4.2.5) lib/active_support/callbacks.rb:81:in `run_callbacks'
    actionpack (4.2.5) lib/abstract_controller/callbacks.rb:19:in `process_action'
    actionpack (4.2.5) lib/action_controller/metal/rescue.rb:29:in `process_action'
    actionpack (4.2.5) lib/action_controller/metal/instrumentation.rb:32:in `block in process_action'
    activesupport (4.2.5) lib/active_support/notifications.rb:164:in `block in instrument'
    activesupport (4.2.5) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
    activesupport (4.2.5) lib/active_support/notifications.rb:164:in `instrument'
    actionpack (4.2.5) lib/action_controller/metal/instrumentation.rb:30:in `process_action'
    actionpack (4.2.5) lib/action_controller/metal/params_wrapper.rb:250:in `process_action'
    activerecord (4.2.5) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
    actionpack (4.2.5) lib/abstract_controller/base.rb:137:in `process'
    actionview (4.2.5) lib/action_view/rendering.rb:30:in `process'
    actionpack (4.2.5) lib/action_controller/metal.rb:196:in `dispatch'
    actionpack (4.2.5) lib/action_controller/metal/rack_delegation.rb:13:in `dispatch'
    actionpack (4.2.5) lib/action_controller/metal.rb:237:in `block in action'
    actionpack (4.2.5) lib/action_dispatch/routing/route_set.rb:76:in `call'
    actionpack (4.2.5) lib/action_dispatch/routing/route_set.rb:76:in `dispatch'
    actionpack (4.2.5) lib/action_dispatch/routing/route_set.rb:45:in `serve'
    actionpack (4.2.5) lib/action_dispatch/journey/router.rb:43:in `block in serve'
    actionpack (4.2.5) lib/action_dispatch/journey/router.rb:30:in `each'
    actionpack (4.2.5) lib/action_dispatch/journey/router.rb:30:in `serve'
    actionpack (4.2.5) lib/action_dispatch/routing/route_set.rb:817:in `call'
    rack (1.6.4) lib/rack/etag.rb:24:in `call'
    rack (1.6.4) lib/rack/conditionalget.rb:25:in `call'
    rack (1.6.4) lib/rack/head.rb:13:in `call'
    actionpack (4.2.5) lib/action_dispatch/middleware/params_parser.rb:27:in `call'
    actionpack (4.2.5) lib/action_dispatch/middleware/flash.rb:260:in `call'
    rack (1.6.4) lib/rack/session/abstract/id.rb:225:in `context'
    rack (1.6.4) lib/rack/session/abstract/id.rb:220:in `call'
    actionpack (4.2.5) lib/action_dispatch/middleware/cookies.rb:560:in `call'
    activerecord (4.2.5) lib/active_record/query_cache.rb:36:in `call'
    activerecord (4.2.5) lib/active_record/connection_adapters/abstract/connection_pool.rb:653:in `call'
    activerecord (4.2.5) lib/active_record/migration.rb:377:in `call'
    actionpack (4.2.5) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
    activesupport (4.2.5) lib/active_support/callbacks.rb:88:in `__run_callbacks__'
    activesupport (4.2.5) lib/active_support/callbacks.rb:778:in `_run_call_callbacks'
    activesupport (4.2.5) lib/active_support/callbacks.rb:81:in `run_callbacks'
    actionpack (4.2.5) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
    actionpack (4.2.5) lib/action_dispatch/middleware/reloader.rb:73:in `call'
    actionpack (4.2.5) lib/action_dispatch/middleware/remote_ip.rb:78:in `call'
    web-console (2.0.0.beta3) lib/action_dispatch/debug_exceptions.rb:18:in `middleware_call'
    web-console (2.0.0.beta3) lib/action_dispatch/debug_exceptions.rb:13:in `call'
    actionpack (4.2.5) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
    railties (4.2.5) lib/rails/rack/logger.rb:38:in `call_app'
    railties (4.2.5) lib/rails/rack/logger.rb:20:in `block in call'
    activesupport (4.2.5) lib/active_support/tagged_logging.rb:68:in `block in tagged'
    activesupport (4.2.5) lib/active_support/tagged_logging.rb:26:in `tagged'
    activesupport (4.2.5) lib/active_support/tagged_logging.rb:68:in `tagged'
    railties (4.2.5) lib/rails/rack/logger.rb:20:in `call'
    actionpack (4.2.5) lib/action_dispatch/middleware/request_id.rb:21:in `call'
    rack (1.6.4) lib/rack/methodoverride.rb:22:in `call'
    rack (1.6.4) lib/rack/runtime.rb:18:in `call'
    activesupport (4.2.5) lib/active_support/cache/strategy/local_cache_middleware.rb:28:in `call'
    rack (1.6.4) lib/rack/lock.rb:17:in `call'
    actionpack (4.2.5) lib/action_dispatch/middleware/static.rb:116:in `call'
    rack (1.6.4) lib/rack/sendfile.rb:113:in `call'
    railties (4.2.5) lib/rails/engine.rb:518:in `call'
    railties (4.2.5) lib/rails/application.rb:165:in `call'
    rack (1.6.4) lib/rack/lock.rb:17:in `call'
    rack (1.6.4) lib/rack/content_length.rb:15:in `call'
    rack (1.6.4) lib/rack/handler/webrick.rb:88:in `service'
    /home/mahesh/.rbenv/versions/2.2.3/lib/ruby/2.2.0/webrick/httpserver.rb:138:in `service'
    /home/mahesh/.rbenv/versions/2.2.3/lib/ruby/2.2.0/webrick/httpserver.rb:94:in `run'
    /home/mahesh/.rbenv/versions/2.2.3/lib/ruby/2.2.0/webrick/server.rb:294:in `block in start_thread'

谢谢。

【问题讨论】：

显示错误的完整堆栈跟踪
我已经添加了完整的错误堆栈跟踪
您似乎尝试在没有参数的情况下调用#password_reset。你必须提供给用户。例如 UserMailer.password_reset(user) 在您的控制器中。
你能显示调用邮件程序的控制器动作吗？
在password_reset方法中，我发送参数user

标签： ruby-on-rails ruby ruby-on-rails-4 passwords reset

【解决方案1】：

由于我的注意力不集中，遇到了同样的问题。检查您的“预览”目录（和 user_mailer_previews.rb）位置：/test 或 /spec。我的在 /spec 中，但我没有看到，所以手动在 /test 中添加了一个。也许你这样做了？

【讨论】：

【解决方案2】：

如果您从控制器发送调用邮件，您还需要将用户对象作为参数传递。

def password_reset_action
    @user = User.find_by_email(params[:email])
    UserMailer.password_reset(@user).deliver
end

您需要找到正在为其重置密码的用户，并将其作为参数传递给 UserMailer 中的方法

【讨论】：