Question

我正在使用牛仔和jiffy（Json库）作为我的websocket ..我可以在我的websocket_handle中从客户端接收数据，截至目前我的代码与此类似

websocket_handle({text, Msg}, Req, Handle) ->
    Message = jiffy:decode(Msg),
    case Message of

pattern1 - ＆gt; ........... pattern2 - ＆gt; .......... 结束， {ok，Res，State}

然而，不是这样，我想在句柄级别模式匹配...

  websocket_handle({text, pattern1}, Req, State),
  websocket_handle({text, pattern2}, Req, State)

问题是我不能在websocket_handle的参数中使用jiffy：decode ...所以我不能写像

 websocket_handle({text, jiffy:decode(Msg), Req, State})

如何使它工作？

Answer 1

如果您喜欢函数签名与案例表达式中的模式匹配，您可以将解码后的消息“转发”到另一个“内部”函数。

websocket_handle({text, Msg}, Req, Handle) ->
    Message = jiffy:decode(Msg),
    websocket_handle_({test, Message}, Req, Handle).

websocket_handle_({text, Pattern1}, Req, Handle) ->
    {ok, Req, State}; 
websocket_handle_({text, Pattern2}, Req, Handle) ->
    {reply, OutFrame | [OutFrame], Req, State};
websocket_handle_({text, PatternN}, Req, Handle) ->
    {ok, Req, State}.

Answer 2

所以只需改为

websocket_handle({text, Msg}, Req, Handle) ->
    websocket_handle_({text, jiffy:decode(Msg)}, Req, Handle).

websocket_handle_({text, Pattern1}, Req, Handle) ->
    %% do stuff,
   {ok, Req, State};
websocket_handle_({text, Pattern2}, Req, Handle) ->
    %% do stuff,
     {reply, [OutFrame], Req, State};
websocket_handle_({text, PatternN}, Req, Handle) ->
    %% do stuff,
     {reply, OutFrame, Req, State}.

牛仔和jiffy websocket_handle事件

2 个答案: