While trying to create a v-data-table, I came across some odd behavior when monitoring the expanded.sync value. The first layer's expanded.sync value seems normal, but the second layer's expanded.sync has three consecutive identical records.
I want to keep an eye on this value and perform actions when collapsing the expanded item. Is there a way to detect when the expanded items are collapsed?
Code for the top layer:
<template>
<v-data-table
:headers="headers"
:items="desserts"
item-key="name"
:expanded.sync="itemExpanded"
show-expand>
>
<template v-slot:top>
<v-toolbar height="38" falt color="#cddde1">
<v-toolbar-title dense> Test </v-toolbar-title>
</v-toolbar>
</template>
<template v-slot:expanded-item="{headers}">
<td :colspan="headers.length">
<Show2></Show2>
</td>
</template>
</v-data-table>
</template>
<script>
import Show2 from "./ShowTest2.vue";
export default {
name: "Show1",
components: {
Show2
},
data: () => ({
itemExpanded:[],
desserts: [
{
name: 'Show 1 - item 1',
calories: 237,
fat: 9.0,
carbs: 37,
protein: 4.3,
iron: '1%',
},
{
name: 'Show 1 - item 2',
calories: 262,
fat: 16.0,
carbs: 23,
protein: 6.0,
iron: '7%',
},
],
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: "details", value: "data-table-expand" },
],
}),
watch: {
itemExpanded(newVal,val){
console.log('layer 1', newVal);
},
},
};
</script>
Code for the second layer:
<template>
<v-data-table
:headers="headers"
:items="desserts"
item-key="name"
:expanded.sync="itemExpanded2"
show-expand>
>
<template v-slot:top>
<v-toolbar>
<v-toolbar-title dense> Test2</v-toolbar-title>
</v-toolbar>
</template>
<template v-slot:expanded-item="{headers}">
<td :colspan="headers.length">
</td>
</template>
</v-data-table>
</template>
<script>
export default {
name: "Show2",
data: () => ({
itemExpanded2:[],
desserts: [
{
name: 'Show 2 - item 1',
calories: 159,
fat: 6.0,
carbs: 24,
protein: 4.0,
iron: '1%',
},
{
name: 'Show 2 - item 2',
calories: 262,
fat: 16.0,
carbs: 23,
protein: 6.0,
iron: '7%',
},
],
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: "details", value: "data-table-expand" },
],
}),
watch: {
itemExpanded2(newVal,val){
console.log('layer2', newVal);
},
},
};
</script>
Console.log output after expanding and collapsing one item in each layer:
layer 1 [__ob__: Observer]
ShowTest.vue?cc9a:66 layer 1 [{…}, __ob__: Observer]
ShowTest2.vue?5475:56 layer2 [{…}, __ob__: Observer]
ShowTest2.vue?5475:56 layer2 [{…}, __ob__: Observer]
ShowTest2.vue?5475:56 layer2 [{…}, __ob__: Observer]
ShowTest2.vue?5475:56 layer2 [__ob__: Observer]
ShowTest2.vue?5475:56 layer2 [__ob__: Observer]
ShowTest2.vue?5475:56 layer2 [__ob__: Observer]
Thank you for your assistance!