ActionView :: Template :: Error（未定义方法`tr'为零：NilClass

Question

我正在测试服务工程师rails gem，并使用VAPID私钥和公钥来发送推送通知。创建推送通知当地，但是当我部署到Heroku上，应用程序提出了试图去推送通知页面时上述错误以下是错误：

 75] Started GET "/push-simple/" for 69.253.120.203 at 2017-02-12 06:37:35 +0000 
2017-02-12T06:37:35.339318+00:00 app[web.1]: [3d626b62-4c1b-41ca-aad3-fc653dc96b75] ActionView::Template::Error (undefined method `tr' for nil:NilClass 
2017-02-12T06:37:35.333379+00:00 app[web.1]: [3d626b62-4c1b-41ca-aad3-fc653dc96b75] Rendering pages/push-simple.html.erb within layouts/application 
2017-02-12T06:37:35.332337+00:00 app[web.1]: [3d626b62-4c1b-41ca-aad3-fc653dc96b75] Processing by PagesController#show as HTML 
2017-02-12T06:37:35.336377+00:00 app[web.1]: [3d626b62-4c1b-41ca-aad3-fc653dc96b75] Rendered pages/push-simple.html.erb within layouts/application (2.8ms) 
2017-02-12T06:37:35.336998+00:00 app[web.1]: [3d626b62-4c1b-41ca-aad3-fc653dc96b75] Completed 500 Internal Server Error in 4ms 
2017-02-12T06:37:35.339281+00:00 app[web.1]: [3d626b62-4c1b-41ca-aad3-fc653dc96b75] 
2017-02-12T06:37:35.339490+00:00 app[web.1]: [3d626b62-4c1b-41ca-aad3-fc653dc96b75]  13: <script type="text/javascript"> 
2017-02-12T06:37:35.339320+00:00 app[web.1]: Did you mean? try): 
2017-02-12T06:37:35.339489+00:00 app[web.1]: [3d626b62-4c1b-41ca-aad3-fc653dc96b75]  11: </div> 
2017-02-12T06:37:35.339489+00:00 app[web.1]: [3d626b62-4c1b-41ca-aad3-fc653dc96b75]  12: 
2017-02-12T06:37:35.339561+00:00 app[web.1]: [3d626b62-4c1b-41ca-aad3-fc653dc96b75] app/views/pages/push-simple.html.erb:14:in `_app_views_pages_push_simple_html_erb__2838769268823495646_39526220' 
2017-02-12T06:37:35.339491+00:00 app[web.1]: [3d626b62-4c1b-41ca-aad3-fc653dc96b75]  15: </script> 
2017-02-12T06:37:35.339491+00:00 app[web.1]: [3d626b62-4c1b-41ca-aad3-fc653dc96b75]  14: var publicKey = new Uint8Array(<%= WebpushClient.public_key_bytes %>); 
2017-02-12T06:37:35.339492+00:00 app[web.1]: [3d626b62-4c1b-41ca-aad3-fc653dc96b75]  16: <%= javascript_include_tag 'push-simple' %> 
2017-02-12T06:37:35.339520+00:00 app[web.1]: [3d626b62-4c1b-41ca-aad3-fc653dc96b75] 
2017-02-12T06:37:35.339560+00:00 app[web.1]: [3d626b62-4c1b-41ca-aad3-fc653dc96b75] app/clients/webpush_client.rb:7:in `public_key_bytes' 

这里是我的webpushclient其中VAPID键被定义为：

class WebpushClient 
    def self.public_key 
     ENV['VAPID_PUBLIC_KEY'] 
    end 

    def self.public_key_bytes 
     Base64.urlsafe_decode64(public_key).bytes 
    end 

    def self.private_key 
     ENV['VAPID_PRIVATE_KEY'] 
    end 

    # Send webpush message using subscription parameters 
    # 
    # @param message [String] text to encrypt 
    # @param subscription_params [Hash<Symbol, String>] 
    # @option subscription_params [String] :endpoint url to send encrypted message 
    # @option subscription_params [Hash<Symbol, String>] :keys auth keys to send with message for decryption 
    # @return true/false 
    def send_notification(message, endpoint: "", p256dh: "", auth: "") 
     raise ArgumentError, ":endpoint param is required" if endpoint.blank? 
     raise ArgumentError, "subscription :keys are missing" if p256dh.blank? || auth.blank? 

     Rails.logger.info("Sending WebPush notification...............") 
     Rails.logger.info("message: #{message}") 
     Rails.logger.info("endpoint: #{endpoint}") 
     Rails.logger.info("p256dh: #{p256dh}") 
     Rails.logger.info("auth: #{auth}") 

     Webpush.payload_send \ 
     message: message, 
     endpoint: endpoint, 
     p256dh: p256dh, 
     auth: auth, 
     vapid: { 
      subject: "jon.corrin@gmail.com", 
      public_key: public_key, 
      private_key: private_key 
     } 
    end 

    def public_key 
     self.class.public_key 
    end 

    def private_key 
     self.class.private_key 
    end 
    end 

这里是脚本im使用cal l公钥：

<script type="text/javascript"> 
    var publicKey = new Uint8Array(<%= WebpushClient.public_key_bytes %>); 
</script> 
<%= javascript_include_tag 'push-react' %> 

就像我之前说的，它在本地工作。我想我可能忘记了定义一个变量，我看过类似的帖子，并且已经调试了相当长的一段时间，但没有运气。有什么建议么？我还想补充一点，我很新，所以如果这是一个明显的错误，我会完全理解。

Answer 1

你的错误是由这种方法来：

def self.public_key_bytes 
    Base64.urlsafe_decode64(public_key).bytes 
end 

仰望source code for Base64#urlsafe_decode64，这被定义为：

def urlsafe_decode64(str) 
    strict_decode64(str.tr("-_", "+/")) 
end 

这是你的undefined method 'tr' for nil:NilClass必须从未来：在public_key。你已经定义了：

def self.public_key 
    ENV['VAPID_PUBLIC_KEY'] 
end 

...换句话说，你没有在你的生产服务器上设置环境变量。这就是为什么它在本地工作，而不是生产。