Vuetify datatable Rows per page is not working

Question

I imported the datatable component from Vuetify and it is working fine except for the Rows per page part. It doesn't open a list that should contain [5, 10, 20] to re-organize the datatable.

update in the photo this is the error, the list of options showing in another place.

I reviewed my code and there is nothing about it. So I deleted the whole component and replaced it with the basic example available in the docs but still the same problem.

<template>
<v-data-table
    :headers="headers"
    :items="desserts"
    class="elevation-1"
  >
    <template v-slot:items="props">
      <td>{{ props.item.name }}</td>
      <td class="text-xs-right">{{ props.item.calories }}</td>
      <td class="text-xs-right">{{ props.item.fat }}</td>
      <td class="text-xs-right">{{ props.item.carbs }}</td>
      <td class="text-xs-right">{{ props.item.protein }}</td>
      <td class="text-xs-right">{{ props.item.iron }}</td>
    </template>
  </v-data-table>
</template>

and the code script part is

<script>
  export default {
    data () {
      return {
        headers: [
          {
            text: 'Dessert (100g serving)',
            align: 'left',
            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' }
        ],
        desserts: [
          {
            name: 'Frozen Yogurt',
            calories: 159,
            fat: 6.0,
            carbs: 24,
            protein: 4.0,
            iron: '1%'
          },
          {
            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%'
          }
        ]
      }
    }
  }
</script>

What should I re-check ?

Answer 1

This behaviour happens, when the template isn't within a <v-app> element. In the main app.vue, from which one calls the component, which uses<v-data-table>, encapsule with <v-app> and <v-content>:

<template>
  <div id="app">
    <v-app>
      <v-content>
        <myComponent></myComponent>
      </v-content>
    </v-app>
  </div>
</template>

Compare to a vuetify tutorial, e.g.a random tutorial.

It seems the dropdowns css class position (top and left) is relative to the pagination element if <v-app> is missing and relative to the 0-position (upper left) of the vuetify table, if the data table is correctly encapsuled.