功能/节点红色的多个输入

Question

OS是Windows 10 / Node-Red版本是1.0.3 / node.js是v12.14.0

我正在尝试将多个msg.payload.subobjects处理到一个功能节点。但是这样做的时候，我总是收到错误“” TypeError：无法读取未定义的属性“ 0”“。

这些节点提供了正确的数据（在调试节点中进行了测试）。但是将它们传递给函数会返回错误。

是否可以处理一个函数的两个输入？因为它们都使用msg.payload对象？

这里是准备测试的版本：

[ 
   { 
      "id":"dd09b1ba.0e51e",
      "type":"tab",
      "label":"Flow 3",
      "disabled":false,
      "info":""
   },
   { 
      "id":"894fec71.7d972",
      "type":"function",
      "z":"dd09b1ba.0e51e",
      "name":"Weather Prediction",
      "func":"var wBees = 0;\nvar wActually = msg.payload.newWt;\n\nvar c0 = msg.payload.data[0].CO2;\nvar c1 = msg.payload.data[1].CO2;\nvar c2 = msg.payload.data[2].CO2;\n\n//wActually.localeCompare(\"rain\") === false\nif(wActually === \"rain\"){\n    wActually = \"good\";\n}else{\n    wActually = \"other\";\n}\n\n//c0, c1, c2 --- 2pm, 10pm, 6am\npredictWeatherByBees = (c0, c1, c2) => {\n  var day = c1-c0;\n  var night = c1-c2;\n\n// Checks proportion\n  if(night > day){\n    // bad weather\n\twBees = \"other\";\n  }else{\n    // good weather\n\twBees = \"good\";\n  }\n  // wait 24hrs\n}\n\n// Evaluation\nif(wBees == wActually){\n    msg.payload.weatherPredict = \"Correct\" + \" || Current: \" + msg.payload.weather;\n\treturn msg;\n}else{\n\tmsg.payload.weatherPredict = \"Incorrect\" + \" || Current: \" + msg.payload.weather;\n\treturn msg;\n}",
      "outputs":1,
      "noerr":0,
      "x":830,
      "y":360,
      "wires":[ 
         [ 
            "3ee84278.8a86de"
         ]
      ]
   },
   { 
      "id":"66456664.9fdde8",
      "type":"function",
      "z":"dd09b1ba.0e51e",
      "name":"convert",
      "func":"msg.payload.newWt = msg.payload[0].weather;\n\nreturn msg;",
      "outputs":1,
      "noerr":0,
      "x":590,
      "y":334,
      "wires":[ 
         [ 
            "bb712a26.743298",
            "894fec71.7d972"
         ]
      ]
   },
   { 
      "id":"63499119.238f9",
      "type":"function",
      "z":"dd09b1ba.0e51e",
      "name":"convert",
      "func":"msg.payload.data = msg.payload;\n\nreturn msg;",
      "outputs":1,
      "noerr":0,
      "x":580,
      "y":400,
      "wires":[ 
         [ 
            "a9e4dd36.5621e",
            "894fec71.7d972"
         ]
      ]
   },
   { 
      "id":"3ee84278.8a86de",
      "type":"debug",
      "z":"dd09b1ba.0e51e",
      "name":"",
      "active":true,
      "tosidebar":true,
      "console":false,
      "tostatus":false,
      "complete":"payload.weatherPredict",
      "targetType":"msg",
      "x":1060,
      "y":360,
      "wires":[ 

      ]
   },
   { 
      "id":"21f342f9.838b4e",
      "type":"inject",
      "z":"dd09b1ba.0e51e",
      "name":"",
      "topic":"",
      "payload":"",
      "payloadType":"date",
      "repeat":"",
      "crontab":"",
      "once":false,
      "onceDelay":0.1,
      "x":180,
      "y":380,
      "wires":[ 
         [ 
            "8995ed2d.942e5",
            "ad132b7f.6096e8"
         ]
      ]
   },
   { 
      "id":"8995ed2d.942e5",
      "type":"function",
      "z":"dd09b1ba.0e51e",
      "name":"object",
      "func":"msg.payload = [{\"Name\":\"C0\",\"CO2\":10}, {\"Name\":\"C1\",\"CO2\":15}, {\"Name\":\"C2\",\"CO2\":20}];\n\nreturn msg;",
      "outputs":1,
      "noerr":0,
      "x":390,
      "y":400,
      "wires":[ 
         [ 
            "63499119.238f9"
         ]
      ]
   },
   { 
      "id":"bb712a26.743298",
      "type":"debug",
      "z":"dd09b1ba.0e51e",
      "name":"",
      "active":true,
      "tosidebar":true,
      "console":false,
      "tostatus":false,
      "complete":"payload.newWt",
      "targetType":"msg",
      "x":800,
      "y":280,
      "wires":[ 

      ]
   },
   { 
      "id":"a9e4dd36.5621e",
      "type":"debug",
      "z":"dd09b1ba.0e51e",
      "name":"",
      "active":true,
      "tosidebar":true,
      "console":false,
      "tostatus":false,
      "complete":"payload.data[0].CO2",
      "targetType":"msg",
      "x":810,
      "y":440,
      "wires":[ 

      ]
   },
   { 
      "id":"ad132b7f.6096e8",
      "type":"function",
      "z":"dd09b1ba.0e51e",
      "name":"object",
      "func":"msg.payload = [{\"weather\": \"mist\"}];\n\nreturn msg;",
      "outputs":1,
      "noerr":0,
      "x":390,
      "y":340,
      "wires":[ 
         [ 
            "66456664.9fdde8"
         ]
      ]
   }
]

Answer 1

问题是Weather Prediction功能节点正在接收2条具有不同结构的独立消息。拆分流时，最终会得到传递到每个分支的消息副本。将它们都连接到功能节点时，它们不会自动合并。

您正在尝试访问功能节点中的两个新消息的一部分。如果您需要两个消息都可以完成此工作，则需要在功能节点之前插入一个join节点，设置为等待2条消息并合并msg.payload值