tencent cloud

Component({
    attached: function() {
      this.setData({
        numberA: 1,
        numberB: 2,
      })
    },
    observers: {
      'numberA, numberB': function(numberA, numberB) {
        // Execute this function when either numberA or numberB is set.
        this.setData({
          sum: numberA + numberB
        })
      }
    }
  })

Component({
    observers: {
      'some.subfield': function(subfield) {
        // Triggered when this.data.some.subfield is set using setData.
        // (In addition, setting this.data.some with setData will also trigger it.)
        subfield === this.data.some.subfield
      },
      'arr[12]': function(arr12) {
        // Triggered when this.data.arr[12] is set using setData
        // (Additionally, setting this.data.arr with setData will also trigger it.)
        arr12 === this.data.arr[12]
      },
    }
})

Component({
    observers: {
      'some.field.**': function(field) {
        // Triggered when this.data.some.field itself or any of its sub-data fields are set using setData.
        // (In addition, setting this.data.some with setData will also trigger it.)
        field === this.data.some.field
      },
    },
    attached: function() {
      // This will trigger the aforementioned listener.
      this.setData({
        'some.field': { /* ... */ }
      })
      // This will also trigger the aforementioned listener.
      this.setData({
        'some.field.xxx': { /* ... */ }
      })
      // This will nonetheless trigger the aforementioned listener.
      this.setData({
        'some': { /* ... */ }
      })
    }
  })

Component({
    observers: {
      '**': function() {
        // Triggered with each setData operation.
      },
    },
  }