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问题是通过Web套接字使用ActionCable广播数据。该错误似乎表明它来自创建方法。NoMethodError(未定义的方法`提取'为零:NilClass)
错误消息
Rendered weight/_weight.html.erb (1.1ms)
[ActionCable] Broadcasting to weight: "<div class=\"row\">\n <div class=\"col-md-8 well\">\n <p>12.0 kg</p>\n <small>less than a minute</small>\n </div>\n</div>"
Completed 500 Internal Server Error in 25ms (Views: 7.4ms | ActiveRecord: 10.6ms)
NoMethodError (undefined method `fetch' for nil:NilClass):
app/controllers/weight_controller.rb:7:in `create'
Rendering /usr/local/rvm/gems/ruby-2.3.4/gems/actionpack-5.0.4/lib/action_dispatch/middleware/templates/rescues/diagnostics.text.erb
Rendering /usr/local/rvm/gems/ruby-2.3.4/gems/actionpack-5.0.4/lib/action_dispatch/middleware/templates/rescues/_source.text.erb
Rendered /usr/local/rvm/gems/ruby-2.3.4/gems/actionpack-5.0.4/lib/action_dispatch/middleware/templates/rescues/_source.text.erb (0.8ms)
Rendering /usr/local/rvm/gems/ruby-2.3.4/gems/actionpack-5.0.4/lib/action_dispatch/middleware/templates/rescues/_trace.text.erb
Rendered /usr/local/rvm/gems/ruby-2.3.4/gems/actionpack-5.0.4/lib/action_dispatch/middleware/templates/rescues/_trace.text.erb (0.9ms)
Rendering /usr/local/rvm/gems/ruby-2.3.4/gems/actionpack-5.0.4/lib/action_dispatch/middleware/templates/rescues/_request_and_response.text.erb
Rendered /usr/local/rvm/gems/ruby-2.3.4/gems/actionpack-5.0.4/lib/action_dispatch/middleware/templates/rescues/_request_and_response.text.erb (1.1ms)
Rendered /usr/local/rvm/gems/ruby-2.3.4/gems/actionpack-5.0.4/lib/action_dispatch/middleware/templates/rescues/diagnostics.text.erb (25.0ms)
从controller.rb创建方法
def create
@weight = Weight.new(weight_params)
@weight.user_id = current_user.id
if @weight.save
ActionCable.server.broadcast "weight", render(partial: 'weight/weight', object: @weight)
else
flash[:danger] = "New Weight was not added!"
redirect_to current_user
end
end
private
def weight_params
params.require(:weights).permit(:weight)
end
我只是不能工作了什么是返回零。信息在广播重量方面正确的事实是正确的,这表明它已将其正确保存到数据库中。想不到还有什么执行'fetch'方法。
很确定网络套接字设置正确。见下文。
配置/ application.rb中:
config.action_cable.mount_path = '/cable'
配置/ routes.rb中:
mount ActionCable.server => '/cable'
weight_channel.rb:
def subscribed
stream_from "weight"
end
weight.coffee:
received: (data) ->
$("#messages").prepend(data)
线是'weight_controller.rb'文件的第7行?你在哪里(如果)调用'fetch'? (在模型的视图中?在由'save'调用的验证中)? – Myst
第7行是上述摘录中的第5行。我没有在任何地方使用抓取。 – will
为了调试目的,考虑将'render'与'broadcast'分开,并将其放在两条不同的行中。即:'tmp = render(partial:'weight/weight',object:@weight)'new line'ActionCable.server.broadcast“weight”,tmp' ...让我们知道哪一行(哪个方法调用)引发新错误。 – Myst