function dataWatch(data) {
  let keyList = {}
  let objHandler = {
    get: function (target, propKey) {
      return target[propKey]
    },
    set: function (target, propKey, value) {
      if (Object.keys(keyList).indexOf(propKey) > -1) {
        keyList[propKey](value)
      }
      target[propKey] = value
    },
  }
  let objProxy = new Proxy(data, objHandler)
  let operater = {
    setData: function (newData) {
      setTimeout(() => {
        for (let key in newData) {
          if (newData.hasOwnProperty(key)) {
            objProxy[key] = newData[key]
          }
        }
      })
    },
    watch: function (key, callback) {
      keyList[key] = callback
    },
  }
  operater.setData(data)
  return operater
}