Vuetify data table v-model is not reactive to changes inside the table items

Question

I have a Vuetify data table that is refreshed from the server every 5 seconds. It has selectable rows. If you select a row, then something in the data changes, the v-model array of selected items does not reflect the changes inside the row items. This codepen is a slightly modified version of a Vuetify example:

https://codepen.io/hobbeschild/pen/bGqGMQQ?editors=1010

Select the first row. At the top you will see the time in the selected item. Wait 5 seconds for the data to refresh. You will see that the selected item time does not match the row item time anymore.

Is there a way to ensure the v-model array contents reflect the new values in the items? I can think of a way to do this programmatically, but I have lots of tables like this and hope there is an easier way, with the table props perhaps.

HTML:

<div id="app">
  <v-app id="inspire">
    <div>selected = {{ selected[0] }}</div>
    <div>
      <v-data-table
        v-model="selected"
        show-select
        item-key="name"
        :headers="headers"
        :items="desserts"
        :options.sync="options"
        :server-items-length="totalDesserts"
        :loading="loading"
        class="elevation-1"
      ></v-data-table>
    </div>
  </v-app>
</div>

JS:

new Vue({
  el: '#app',
  vuetify: new Vuetify(),
  data () {
    return {
      selected: [],
      totalDesserts: 0,
      desserts: [],
      loading: true,
      options: {},
      headers: [
        {
          text: 'Dessert (100g serving)',
          align: 'start',
          sortable: false,
          value: 'name',
        },
        { text: 'Calories', value: 'calories' },
        { text: 'Fat (g)', value: 'fat' },
        { text: 'Carbs (g)', value: 'carbs' },
        { text: 'Protein (g)', value: 'protein' },
        { text: 'Iron (%)', value: 'iron' },
        { text: 'Time', value: 'time' },
      ],
      reloadTimerId: Number,
    }
  },
  watch: {
    options: {
      handler () {
        this.getDataFromApi()
      },
      deep: true,
    },
  },
  mounted () {
    this.getDataFromApi();
    this.reloadTimerId = setInterval(this.getDataFromApi, 5000);
  },
  methods: {
    getDataFromApi () {
      this.loading = true
      this.fakeApiCall().then(data => {
        this.desserts = data.items
        this.totalDesserts = data.total
        this.loading = false
      })
    },
    /**
     * In a real application this would be a call to fetch() or axios.get()
     */
    fakeApiCall () {
      return new Promise((resolve, reject) => {
        const { sortBy, sortDesc, page, itemsPerPage } = this.options

        let items = this.getDesserts()
        const total = items.length

        if (sortBy.length === 1 && sortDesc.length === 1) {
          items = items.sort((a, b) => {
            const sortA = a[sortBy[0]]
            const sortB = b[sortBy[0]]

            if (sortDesc[0]) {
              if (sortA < sortB) return 1
              if (sortA > sortB) return -1
              return 0
            } else {
              if (sortA < sortB) return -1
              if (sortA > sortB) return 1
              return 0
            }
          })
        }

        if (itemsPerPage > 0) {
          items = items.slice((page - 1) * itemsPerPage, page * itemsPerPage)
        }

        setTimeout(() => {
          resolve({
            items,
            total,
          })
        }, 1000)
      })
    },
    getDesserts () {
      return [
        {
          name: 'Frozen Yogurt',
          calories: 159,
          fat: 6.0,
          carbs: 24,
          protein: 4.0,
          iron: '1%',
          time: new Date(),
        },
        {
          name: 'Ice cream sandwich',
          calories: 237,
          fat: 9.0,
          carbs: 37,
          protein: 4.3,
          iron: '1%',
        },
        {
          name: 'Eclair',
          calories: 262,
          fat: 16.0,
          carbs: 23,
          protein: 6.0,
          iron: '7%',
        },
        {
          name: 'Cupcake',
          calories: 305,
          fat: 3.7,
          carbs: 67,
          protein: 4.3,
          iron: '8%',
        },
        {
          name: 'Gingerbread',
          calories: 356,
          fat: 16.0,
          carbs: 49,
          protein: 3.9,
          iron: '16%',
        },
        {
          name: 'Jelly bean',
          calories: 375,
          fat: 0.0,
          carbs: 94,
          protein: 0.0,
          iron: '0%',
        },
        {
          name: 'Lollipop',
          calories: 392,
          fat: 0.2,
          carbs: 98,
          protein: 0,
          iron: '2%',
        },
        {
          name: 'Honeycomb',
          calories: 408,
          fat: 3.2,
          carbs: 87,
          protein: 6.5,
          iron: '45%',
        },
        {
          name: 'Donut',
          calories: 452,
          fat: 25.0,
          carbs: 51,
          protein: 4.9,
          iron: '22%',
        },
        {
          name: 'KitKat',
          calories: 518,
          fat: 26.0,
          carbs: 65,
          protein: 7,
          iron: '6%',
        },
      ]
    },
  },
})

Answer 1

I do not think there is any "build-in" way to do what you want. Problem is model (selected in your code) holds references of selected objects from items/deserts array. If you replace items/deserts (with this.desserts = data.items) with completely new array containing completely new objects, this is what you get...

So doing this yourself is most certainly only way. Either:

1. Recreate selected whenever you replace items/deserts

this.selected = data.items.filter(i => this.selected.findIndex(item => item.name === i.name) > -1)

2. Or do not replace array and it's items - update existing objects with new data instead