ruby-on-rails - HTTParty 未定义方法 '+' 为 nil :NilClass

Question

使用 HTTPParty gem 连接到天气 API 我有以下方法:

def weather_search
  @city_name = params[:city_name]
  url = URI.encode("api.openweathermap.org/data/2.5/weather?q=#{@city_name}&APPID=#{API_TOKEN}")
  @search_result = HTTParty.get(url)
end

gem 已安装。

使用 postman ，我可以通过以下 url 毫无问题地访问 API

api.openweathermap.org/data/2.5/weather?q=banfield&APPID=xxxxxxxxxxxxxxx

但是在我的 rails 4 应用程序中，相同的 url 会抛出错误

undefined method '+' for nil:NilClass 在我声明的那一行

@search_result = HTTParty.get(url)

我找到了 this和 this other关于这个主题的帖子，但两者都没有帮助。

堆栈跟踪:

Started POST "/search_city_weather" for 127.0.0.1 at 2016-03-30 23:50:13 +0100
Processing by WeatherChecksController#weather_search as HTML
  Parameters: {"utf8"=>"✓", "authenticity_token"=>"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx", "city_name"=>"banfield", "commit"=>"Search"}
api.openweathermap.org/data/2.5/weather?q=banfield&APPID=xxxxxxxxxxxxxxxxxx
Completed 500 Internal Server Error in 11ms
NoMethodError (undefined method `+' for nil:NilClass):
  app/controllers/weather_checks_controller.rb:24:in `weather_search'
  Rendered /home/xxxx/.rvm/gems/ruby-2.2.2/gems/actionpack-4.1.4/lib/action_dispatch/middleware/templates/rescues/_source.erb (1.3ms)
  Rendered /home/xxxx/.rvm/gems/ruby-2.2.2/gems/actionpack-4.1.4/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb (2.1ms)
  Rendered /home/xxxx/.rvm/gems/ruby-2.2.2/gems/actionpack-4.1.4/lib/action_dispatch/middleware/templates/rescues/_request_and_response.html.erb (1.3ms)
  Rendered /home/xxxx/.rvm/gems/ruby-2.2.2/gems/actionpack-4.1.4/lib/action_dispatch/middleware/templates/rescues/diagnostics.erb within rescues/layout (22.6ms)

任何帮助将不胜感激。

Answer 1

正如@tadman 所写，您应该为 httparty 提供一个有效的 URI，所以:

• http://foo.com/resource , 会起作用。
• foo.com/resource，不会。

顺便说一句，在 0.14.0 之后的版本中，在这些情况下，Httparty 将返回此错误:URI::InvalidURIError:错误的 URI(不是 URI？):

比这更清楚

undefined method '+' for nil:NilClass