没有将 nil 隐式转换为字符串（赞助）

Question

我收到上述错误，它说它与“+”有关。请注意，我没有对下面的页面进行编码，但我被告知要修复它。如果有人可以提供帮助，那就太好了。

MYMOH 控制器

 210. def sponsorships
 211. dbdc_client.materialize("cv__Recurring_Gift__c")
 212. #@gifts =Cv__Recurring_Gift__c.find_all_by_cv__Contact__c(current_user.convio_id)
 213. @gifts = Cv__Recurring_Gift__c.query("cv__Contact__c = '" + current_user.convio_id + "' AND Child_Status__c = 'Sponsored' and cv__Recurring_Gift_Status__c='Active'")
 214. @account = Contact.find_by_Id(current_user.convio_id)
 215. #@old_sponsorships = Child_Sponsorship__c.query("Sponsor__c = '" + current_user.convio_id + "' AND Status__c = 'Open'")
 216. @sponsorships = @gifts # + @old_sponsorships
 217. unless @sponsorships.nil?
 218.  #if we find sponsorships
 219.  @children = []
 220.  @sponsorships.each do | spons |
 221.    @photo = nil
 222.      unless spons.Child__c.nil?
 223.        @child = Child__c.find_by_Id(spons.Child__c)
 224.            @photoTest = Picture__c.query("Child__c='" + @child.Id + "' and Primary__c=true").first
 225.            @photo = @photoTest.Photo__c if @photoTest
 226.            if @photo.nil?
 227.              @attachment = Attachment.find_by_ParentId(@child.Id)
 228.              @photo = "<img src='https://c.na12.content.force.com/servlet/servlet.FileDownload?file=" + @attachment.Id.to_s + "' />" unless @attachment.nil?
             end
             #set an unused variable to carry the photo url
             @child.LastModifiedById = @photo
             #add child to array of children
             @children << @child
        end
  end
end

end

完整跟踪

app/controllers/mymoh_controller.rb:213:in `+'
app/controllers/mymoh_controller.rb:213:in `sponsorships'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/action_controller/metal/implicit_render.rb:4:in `send_action'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/abstract_controller/base.rb:167:in `process_action'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/action_controller/metal/rendering.rb:10:in `process_action'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/abstract_controller/callbacks.rb:18:in `block in process_action'
vendor/bundle/ruby/2.1.0/gems/activesupport-3.2.11/lib/active_support/callbacks.rb:425:in `_run__3687996442544047678__process_action__3216127983448203575__callbacks'
vendor/bundle/ruby/2.1.0/gems/activesupport-3.2.11/lib/active_support/callbacks.rb:405:in `__run_callback'
vendor/bundle/ruby/2.1.0/gems/activesupport-3.2.11/lib/active_support/callbacks.rb:385:in `_run_process_action_callbacks'
vendor/bundle/ruby/2.1.0/gems/activesupport-3.2.11/lib/active_support/callbacks.rb:81:in `run_callbacks'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/abstract_controller/callbacks.rb:17:in `process_action'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/action_controller/metal/rescue.rb:29:in `process_action'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/action_controller/metal/instrumentation.rb:30:in `block in process_action'
vendor/bundle/ruby/2.1.0/gems/activesupport-3.2.11/lib/active_support/notifications.rb:123:in `block in instrument'
vendor/bundle/ruby/2.1.0/gems/activesupport-3.2.11/lib/active_support/notifications/instrumenter.rb:20:in `instrument'
vendor/bundle/ruby/2.1.0/gems/activesupport-3.2.11/lib/active_support/notifications.rb:123:in `instrument'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/action_controller/metal/instrumentation.rb:29:in `process_action'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/action_controller/metal/params_wrapper.rb:207:in `process_action'
vendor/bundle/ruby/2.1.0/gems/activerecord-3.2.11/lib/active_record/railties/controller_runtime.rb:18:in `process_action'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/rails3/action_controller.rb:23:in `block in process_action'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/controller_instrumentation.rb:353:in `perform_action_with_newrelic_trace'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/rails3/action_controller.rb:22:in `process_action'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/abstract_controller/base.rb:121:in `process'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/abstract_controller/rendering.rb:45:in `process'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/action_controller/metal.rb:203:in `dispatch'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/action_controller/metal/rack_delegation.rb:14:in `dispatch'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/action_controller/metal.rb:246:in `block in action'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/action_dispatch/routing/route_set.rb:73:in `call'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/action_dispatch/routing/route_set.rb:73:in `dispatch'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/action_dispatch/routing/route_set.rb:36:in `call'
vendor/bundle/ruby/2.1.0/gems/journey-1.0.4/lib/journey/router.rb:68:in `block in call'
vendor/bundle/ruby/2.1.0/gems/journey-1.0.4/lib/journey/router.rb:56:in `each'
vendor/bundle/ruby/2.1.0/gems/journey-1.0.4/lib/journey/router.rb:56:in `call'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/action_dispatch/routing/route_set.rb:601:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/rack/agent_hooks.rb:30:in `traced_call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/rack/browser_monitoring.rb:23:in `traced_call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/exception_notification-4.0.0/lib/exception_notification/rack.rb:28:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/action_dispatch/middleware/best_standards_support.rb:17:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/rack-1.4.5/lib/rack/etag.rb:23:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/rack-1.4.5/lib/rack/conditionalget.rb:25:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/action_dispatch/middleware/head.rb:14:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/action_dispatch/middleware/params_parser.rb:21:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/action_dispatch/middleware/flash.rb:242:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/rack-1.4.5/lib/rack/session/abstract/id.rb:210:in `context'
vendor/bundle/ruby/2.1.0/gems/rack-1.4.5/lib/rack/session/abstract/id.rb:205:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/action_dispatch/middleware/cookies.rb:341:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/activerecord-3.2.11/lib/active_record/query_cache.rb:64:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/activerecord-3.2.11/lib/active_record/connection_adapters/abstract/connection_pool.rb:479:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/action_dispatch/middleware/callbacks.rb:28:in `block in call'
vendor/bundle/ruby/2.1.0/gems/activesupport-3.2.11/lib/active_support/callbacks.rb:405:in `_run__790379348702901205__call__4407048364405463113__callbacks'
vendor/bundle/ruby/2.1.0/gems/activesupport-3.2.11/lib/active_support/callbacks.rb:405:in `__run_callback'
vendor/bundle/ruby/2.1.0/gems/activesupport-3.2.11/lib/active_support/callbacks.rb:385:in `_run_call_callbacks'
vendor/bundle/ruby/2.1.0/gems/activesupport-3.2.11/lib/active_support/callbacks.rb:81:in `run_callbacks'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/action_dispatch/middleware/callbacks.rb:27:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/action_dispatch/middleware/remote_ip.rb:31:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/action_dispatch/middleware/debug_exceptions.rb:16:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/action_dispatch/middleware/show_exceptions.rb:56:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/railties-3.2.11/lib/rails/rack/logger.rb:32:in `call_app'
vendor/bundle/ruby/2.1.0/gems/railties-3.2.11/lib/rails/rack/logger.rb:16:in `block in call'
vendor/bundle/ruby/2.1.0/gems/activesupport-3.2.11/lib/active_support/tagged_logging.rb:22:in `tagged'
vendor/bundle/ruby/2.1.0/gems/railties-3.2.11/lib/rails/rack/logger.rb:16:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/action_dispatch/middleware/request_id.rb:22:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/rack-1.4.5/lib/rack/methodoverride.rb:21:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/rack-1.4.5/lib/rack/runtime.rb:17:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/activesupport-3.2.11/lib/active_support/cache/strategy/local_cache.rb:72:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/rack-1.4.5/lib/rack/lock.rb:15:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/actionpack-3.2.11/lib/action_dispatch/middleware/static.rb:62:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/rack-cache-1.2/lib/rack/cache/context.rb:136:in `forward'
vendor/bundle/ruby/2.1.0/gems/rack-cache-1.2/lib/rack/cache/context.rb:245:in `fetch'
vendor/bundle/ruby/2.1.0/gems/rack-cache-1.2/lib/rack/cache/context.rb:185:in `lookup'
vendor/bundle/ruby/2.1.0/gems/rack-cache-1.2/lib/rack/cache/context.rb:66:in `call!'
vendor/bundle/ruby/2.1.0/gems/rack-cache-1.2/lib/rack/cache/context.rb:51:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/rack-timeout-0.2.4/lib/rack/timeout.rb:108:in `call'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/railties-3.2.11/lib/rails/engine.rb:479:in `call'
vendor/bundle/ruby/2.1.0/gems/railties-3.2.11/lib/rails/application.rb:223:in `call'
vendor/bundle/ruby/2.1.0/gems/railties-3.2.11/lib/rails/railtie/configurable.rb:30:in `method_missing'
vendor/bundle/ruby/2.1.0/gems/newrelic_rpm-3.11.2.286/lib/new_relic/agent/instrumentation/middleware_tracing.rb:67:in `call'
vendor/bundle/ruby/2.1.0/gems/rack-1.4.5/lib/rack/content_length.rb:14:in `call'
vendor/bundle/ruby/2.1.0/gems/railties-3.2.11/lib/rails/rack/log_tailer.rb:17:in `call'
vendor/bundle/ruby/2.1.0/gems/thin-1.6.3/lib/thin/connection.rb:86:in `block in pre_process'
vendor/bundle/ruby/2.1.0/gems/thin-1.6.3/lib/thin/connection.rb:84:in `catch'
vendor/bundle/ruby/2.1.0/gems/thin-1.6.3/lib/thin/connection.rb:84:in `pre_process'
vendor/bundle/ruby/2.1.0/gems/thin-1.6.3/lib/thin/connection.rb:53:in `process'
vendor/bundle/ruby/2.1.0/gems/thin-1.6.3/lib/thin/connection.rb:39:in `receive_data'
vendor/bundle/ruby/2.1.0/gems/eventmachine-1.0.7/lib/eventmachine.rb:187:in `run_machine'
vendor/bundle/ruby/2.1.0/gems/eventmachine-1.0.7/lib/eventmachine.rb:187:in `run'
vendor/bundle/ruby/2.1.0/gems/thin-1.6.3/lib/thin/backends/base.rb:73:in `start'
vendor/bundle/ruby/2.1.0/gems/thin-1.6.3/lib/thin/server.rb:162:in `start'
vendor/bundle/ruby/2.1.0/gems/rack-1.4.5/lib/rack/handler/thin.rb:13:in `run'
vendor/bundle/ruby/2.1.0/gems/rack-1.4.5/lib/rack/server.rb:268:in `start'
vendor/bundle/ruby/2.1.0/gems/railties-3.2.11/lib/rails/commands/server.rb:70:in `start'
vendor/bundle/ruby/2.1.0/gems/railties-3.2.11/lib/rails/commands.rb:55:in `block in <top (required)>'
vendor/bundle/ruby/2.1.0/gems/railties-3.2.11/lib/rails/commands.rb:50:in `tap'
vendor/bundle/ruby/2.1.0/gems/railties-3.2.11/lib/rails/commands.rb:50:in `<top (required)>'
script/rails:6:in `require'
script/rails:6:in `<main>'

Answer 1

@pref 并没有被声明为一个字符串，只是通过分配它“”。

试试这个：

preferences = String.new
if !params[:prefgirl].nil?
    preferences = preferences + "Girl,"
end
.
.
.
@preferences = preferences

Answer 2

感谢您发布代码。如果堆栈跟踪指向正确的位置，则错误就在这里，您正在构建这样的字符串：

"cv__Contact__c = '" + current_user.convio_id + "' AND Child_Status__c = 'Sponsored' and cv__Recurring_Gift_Status__c='Active'"

如果 current_user.convio_id 为 nil，您将收到您引用的错误。您应该考虑防止 current_user.convio_id 为 nil，或者如果为 nil，则应如何构建该查询。

顺便说一句，构建该字符串的更 Rubyish 方式是使用插值：

"cv__Contact__c = '#{current_user.convio_id}' AND Child_Status__c = 'Sponsored' and cv__Recurring_Gift_Status__c='Active'"

Answer 3

该错误具体表示current_user.convio_id 是nil，并且Ruby 不会在没有被直接告知的情况下将nil 转换为字符串。如果左侧的对象是字符串，+ 将连接字符串。

您的整个sponsorship 操作似乎取决于拥有convio_id 的用户如果这是所有 用户应该拥有的字段，您应该为其添加not null 属性，并且浏览并为所有当前没有的添加一个。

如果convio_id 是可选的，您应该在操作开始时检查他们是否有前任-

def sponsorships
  if current_user.convio_id.nil?
    flash[:convio_id] = "User has no Convio ID" # optional message saying why we're redirecting
    redirect_to <somewhere else> and return
  end
  <rest of the code here>

要在 Ruby 中根据需要添加字段，忽略数据库，您需要将此行添加到您的模型中，可能是 app/models/user.rb

class User < ActiveRecord::Base
  ...
  validates :convio_id, presence: true
  ...
end

这将使通过该网站创建的所有用户都必须具有convio_id 才能有效并保存。