Action Controller：异常捕获[Home＃索引中的NoMethodError]

Question

我正在尝试为从以前的开发人员传递给我的ROR应用程序设置本地开发环境。我是ROR和Ruby的新手。

首先我运行bundle install没有问题，然后mongod。当我运行rails s服务器启动，但它输出host is not a valid option for Mongo::Connection。当我尝试去http://0.0.0.0:3000出现错误信息。 NoMethodError in Home#index

错误指向以下路径：

显示/Users/ryansnyder/Rails/myAppX/app/views/home/index.html.haml其中行＃12提出：

undefined method 'url' for nil:NilClass

提取的源（围绕线＃12）：

9:  %h2 Asset Protection 
10:  = link_to image_tag('asset-protection-guide.png'), 'http://myAppX.s3.amazonaws.com/assets/downloads/myAppX-AssetProtectionGuide.pdf', :title => 'Asset Protection Guide', :alt => 'Download our Asset Protection Guide', :target => '_blank' 
11: %section#graphs 
12:  = link_to image_tag(@chart.url, :alt => @chart.alt), eval(@chart.link), :title => @chart.title 
13: 
14: %section#recent-happenings 
15: %section#upcoming-events 

我在注释该行.haml文件，并刷新http://0.0.0.0:3000并收到另一个undefined method 'question' for nil:NilClass错误。我认为这是一个数据库或错误处理问题。但我只是在猜测。

编辑： 我不知道这是否有帮助，但运行时rake test我收到以下输出。

host is not a valid option for Mongo::Connection 
/Users/ryansnyder/.rvm/gems/ruby-1.9.2-p290/gems/activesupport-3.0.19/lib/active_support/dependencies.rb:242:in `require': no such file to load -- turn (LoadError) 
    from /Users/ryansnyder/.rvm/gems/ruby-1.9.2-p290/gems/activesupport-3.0.19/lib/active_support/dependencies.rb:242:in `block in require' 
    from /Users/ryansnyder/.rvm/gems/ruby-1.9.2-p290/gems/activesupport-3.0.19/lib/active_support/dependencies.rb:227:in `load_dependency' 
    from /Users/ryansnyder/.rvm/gems/ruby-1.9.2-p290/gems/activesupport-3.0.19/lib/active_support/dependencies.rb:242:in `require' 
    from /Users/ryansnyder/Rails/alerstallings-master/test/test_helper.rb:4:in `<top (required)>' 
    from /Users/ryansnyder/Rails/alerstallings-master/test/functional/lawyers_controller_test.rb:1:in `require' 
    from /Users/ryansnyder/Rails/alerstallings-master/test/functional/lawyers_controller_test.rb:1:in `<top (required)>' 
    from /Users/ryansnyder/.rvm/gems/ruby-1.9.2-p290@global/gems/rake-10.0.3/lib/rake/rake_test_loader.rb:10:in `require' 
    from /Users/ryansnyder/.rvm/gems/ruby-1.9.2-p290@global/gems/rake-10.0.3/lib/rake/rake_test_loader.rb:10:in `block (2 levels) in <main>' 
    from /Users/ryansnyder/.rvm/gems/ruby-1.9.2-p290@global/gems/rake-10.0.3/lib/rake/rake_test_loader.rb:9:in `each' 
    from /Users/ryansnyder/.rvm/gems/ruby-1.9.2-p290@global/gems/rake-10.0.3/lib/rake/rake_test_loader.rb:9:in `block in <main>' 
    from /Users/ryansnyder/.rvm/gems/ruby-1.9.2-p290@global/gems/rake-10.0.3/lib/rake/rake_test_loader.rb:4:in `select' 
    from /Users/ryansnyder/.rvm/gems/ruby-1.9.2-p290@global/gems/rake-10.0.3/lib/rake/rake_test_loader.rb:4:in `<main>' 
Errors running test:functionals! 

编辑2： mondoid.yml

defaults: &defaults 
    host: localhost 
    # slaves: 
    # - host: slave1.local 
    #  port: 27018 
    # - host: slave2.local 
    #  port: 27019 

development: 
    <<: *defaults 
    database: alerstallings_development 

test: 
    <<: *defaults 
    database: alerstallings_test 

staging: 
    uri: <%= ENV['MONGOHQ_URL'] %> 

# set these environment variables on your prod server 
production: 
    uri: <%= ENV['MONGOHQ_URL'] %> 

任何帮助，将不胜感激。

Answer 1

你需要检查你找回的对象不是零。您应该添加一些错误处理并检查您的数据库是否正在返回适当的对象。速战速决将有条件地运行您的代码：

unless @chart.nil? 
    # Your previous code here 
end