Question

我尝试按照以下链接将网络套接字集成到我的Rails应用程序中：https://github.com/websocket-rails/websocket-rails/wiki/Installation-and-Setup

我使用Ruby 2.0和Rails3。相关文件的内容：

的Gemfile：

gem 'websocket-rails

events.rb

WebsocketRails::EventMap.describe do
subscribe :awesomeness_approval, :to => ChatController, :with_method =>   :awesomeness_approval
end

development.rb

... config.middleware.delete Rack :: Lock ...

chat_controller.rb

class ChatController < WebsocketRails::BaseController
def initialize_session
# perform application setup here
controller_store[:message_count] = 0
end

def awesomeness_approval
if message[:awesomeness] > 5
trigger_success {:m => 'awesome level is sufficient'}
else
trigger_failure {:m => 'awesome level is insufficient'}
end
end
end

chat.js

var dispatcher = new WebSocketRails('localhost:3000/websocket');
dispatcher.on_open = function(data) {
  console.log('Connection has been established: ', data);
}

var success = function(response) {
  console.log("You are awesome because: "+response.message);
}

var failure = function(response) {
  console.log("You are not very awesome because: "+response.message);
}

var message = { awesomeness: 4 }
dispatcher.trigger('awesomeness_approval', message, success, failure);

当我尝试启动rails服务器时，出现以下错误：

w/app/controllers/chat_controller.rb:9: syntax error, unexpected =>, expecting '}' (SyntaxError)
    trigger_success {:m => 'awesome level is sufficient'}

...

/app/controllers/chat_controller.rb:11: syntax error, unexpected =>, expecting '}'
    trigger_failure {:m => 'awesome level is insufficient'}

但是，如果我注释掉上述内容，我就可以启动服务器，并且浏览器可以连接到Web套接字。在浏览器控制台上可以看到以下输出：

"Connection has been established: " Object { connection_id: "f66c4298eb103312e181" } chat.js:3

请帮忙。

Answer 1

您的错误来自方法调用中的语法歧义。

写作时

trigger_success {:m => 'awesome level is sufficient'}

开口大括号被解释为该方法的块参数的开始。但是，您打算将它作为哈希。解释为一个块，它确实是错误的语法，因为一个块不允许一个简单的哈希火箭。

您可以解决这种歧义，您可以使用括号：

trigger_success({:m => 'awesome level is sufficient'})

这样一来，ruby解析器很明显你实际上是指将一个hash参数传递给方法并且当前正在解析。

如何在Rails中使用websockets

1 个答案: