求懂JavaScript的大神帮忙在nodered里面转换下json （已解决)

xieahui

24元的那个GPS模块F大获取的JSON是下面这样的格式
求大神帮忙转换下只需要longitude和latitude的JSON格式
然后MQTT给homeassistant

    
{
  "ret": 0,
  "msg": "OK",
  "data": [
    {
      "imei": "862964024393013",
      "name": "RW67",
      "dev_type": "W1",
      "device_info": 0,
      "device_info_new": 4,
      "seconds": 20387,
      "gps_time": 1556757183,
      "sys_time": 1556757179,
      "heart_time": 1556777550,
      "server_time": 1556777566,
      "lng": 121.15726,
      "lat": 28.338941,
      "course": ……………………
      "group_id": 0
    }
  ]
}

//帮忙转换成下面这种格式让HA-MQTT-device_tracker

{
  "longitude": 121.15726,
  "latitude": 28.338941
}

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下面是node red的大神帮忙转换下啊 不懂JSON自己去百度google搞不定
以下是nodered代码或文件

[{"id":"8924f1d0.5a5fb","type":"tab","label":"1","disabled":false,"info":""},{"id":"9a1fa073.93115","type":"mqtt out","z":"8924f1d0.5a5fb","name":"","topic":"phone/location/tracker","qos":"","retain":"","broker":"64f0b1f0.c4999","x":580,"y":220,"wires":[]},{"id":"bafaf3da.574a","type":"inject","z":"8924f1d0.5a5fb","name":"手动输入GPS","topic":"","payload":"{   "ret": 0,   "msg": "OK",   "data": [     {       "imei": "862964024393013",       "name": "RW67",       "dev_type": "W1",       "device_info": 0,       "device_info_new": 4,       "seconds": 20387,       "gps_time": 1556757183,       "sys_time": 1556757179,       "heart_time": 1556777550,       "server_time": 1556777566,       "lng": 121.15726,       "lat": 28.338941,       "course": 88,       "speed": 11,       "status": "01390488000000000001000000000000",       "power": "51%",       "location": "GPS",       "acc": "-1",       "acc_seconds": 0,       "group_id": 0     }   ] }","payloadType":"json","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":250,"y":220,"wires":[["9a1fa073.93115","26d49fba.9442c","40f39ac0.ecbec4"]]},{"id":"40f39ac0.ecbec4","type":"debug","z":"8924f1d0.5a5fb","name":"成功","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","targetType":"msg","x":590,"y":280,"wires":[]},{"id":"26d49fba.9442c","type":"function","z":"8924f1d0.5a5fb","name":"解析求助","func":"const longitude = msg.payload.msg\nconst latitude = msg.payload.msg\nreturn {longitude,latitude}\n\n//我乱写的","outputs":1,"noerr":0,"x":420,"y":280,"wires":[["40f39ac0.ecbec4"]]},{"id":"64f0b1f0.c4999","type":"mqtt-broker","z":"","name":"","broker":"192.168.203.205","port":"1883","clientid":"203205","usetls":false,"compatmode":true,"keepalive":"60","cleansession":true,"birthTopic":"","birthQos":"0","birthPayload":"","closeTopic":"","closeQos":"0","closePayload":"","willTopic":"","willQos":"0","willPayload":""}]

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natic

写段js代码转换这种？

xieahui

natic 发表于 2019-5-6 14:13
写段js代码转换这种？

嗯 那晚你说看书去来着……
就是获取的数据是这样
然后喜欢转换下 简单的两个 坐标参数  MQTT给ha

natic

xieahui 发表于 2019-5-6 14:16
嗯 那晚你说看书去来着……
就是获取的数据是这样
然后喜欢转换下 简单的两个 坐标参数  MQTT给ha ...

这个简单，我给你写一个，原始的数据是啥？

xieahui

natic 发表于 2019-5-6 14:17
这个简单，我给你写一个，原始的数据是啥？

原始获取的数据就是这样的 下面一大段话 帮转 两个坐标参数
{
  "ret": 0,
  "msg": "OK",
  "data": [
    {
      "imei": "862964024393013",
      "name": "RW67",
      "dev_type": "W1",
      "device_info": 0,
      "device_info_new": 4,
      "seconds": 20387,
      "gps_time": 1556757183,
      "sys_time": 1556757179,
      "heart_time": 1556777550,
      "server_time": 1556777566,
      "lng": 121.15726,
      "lat": 28.338941,
      "course": ……………………
      "group_id": 0
    }
  ]
}
 
//帮忙转换成下面这种格式让HA-MQTT-device_tracker
 
{
  "longitude": 121.15726,
  "latitude": 28.338941
}

复制代码

oemsys

{
  "longitude": msg.payload.data.lng,
  "latitude": msg.payload.data.lat
}

xieahui

oemsys 发表于 2019-5-6 14:22
{
  "longitude": msg.payload.data.lng,
  "latitude": msg.payload.data.lat

node red上如何写啊？
我要输出给MQTT 不是很懂如何操作

natic

var json = JSON.parse('{"ret": 0,"msg": "OK","data": [{"imei": "862964024393013","name": "RW67","dev_type": "W1","device_info": 0,"device_info_new": 4,"seconds": 20387,"gps_time": 1556757183,"sys_time": 1556757179,"heart_time": 1556777550,"server_time": 1556777566,"lng": 121.15726,"lat": 28.338941,"course": "","group_id": 0}]}');
var json2 = {};
json2.longitude = json.data[0].lng;
json2.latitude = json.data[0].lat;
var result = JSON.stringify(result);
console.log(result);

natic

还有一个问题，是你这个data里面有很多值，有可能会有几个，全部取出来还是固定取一个

令狐鸣

// 原始数据
let loc = msg.payload;
// 转换数据
let result = 
{
  "longitude": loc.data[0].lng,
  "latitude": loc.data[0].lat
}

msg.payload = result;
return msg;