Quasar is a popular Vue UI library for developing good looking Vue apps.
In this article, we’ll take a look at how to create Vue apps with the Quasar UI library.
Virtual Scrolling
With q-table ‘s virtual-scroll prop, we can add virtual scrolling to our table.
It improves the performance of the table when we need to display lots of data by loading only the ones that are displayed.
For instance, we can write:
<!DOCTYPE html>
<html>
<head>
<link
href="https://fonts.googleapis.com/css?family=Roboto:100,300,400,500,700,900|Material+Icons"
rel="stylesheet"
type="text/css"
/>
<link
href="https://cdn.jsdelivr.net/npm/quasar@1.12.13/dist/quasar.min.css"
rel="stylesheet"
type="text/css"
/>
</head>
<body class="body--dark">
<script src="https://cdn.jsdelivr.net/npm/vue@^2.0.0/dist/vue.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/quasar@1.12.13/dist/quasar.umd.min.js"></script>
<div id="q-app">
<q-layout
view="lHh Lpr lFf"
container
style="height: 100vh;"
class="shadow-2 rounded-borders"
>
<div class="q-pa-md">
<q-table
style="height: 400px;"
title="Treats"
:data="data"
:columns="columns"
row-key="index"
virtual-scroll
:pagination.sync="pagination"
:rows-per-page-options="[0]"
>
</q-table>
</div>
</q-layout>
</div>
<script>
const columns = [
{
name: "name",
required: true,
label: "Dessert",
align: "left",
field: (row) => row.name,
format: (val) => `${val}`,
sortable: true
},
{
name: "calories",
align: "center",
label: "Calories",
field: "calories",
sortable: true
},
{ name: "fat", label: "Fat (g)", field: "fat", sortable: true },
{
name: "calcium",
label: "Calcium (%)",
field: "calcium",
sortable: true,
sort: (a, b) => parseInt(a, 10) - parseInt(b, 10)
}
];
const seed = [
{
name: "Frozen Yogurt",
calories: 159,
fat: 6.0,
calcium: "14%"
},
{
name: "Ice cream sandwich",
calories: 237,
fat: 9.0,
calcium: "8%"
},
{
name: "Eclair",
calories: 262,
fat: 16.0,
calcium: "6%"
},
{
name: "Honeycomb",
calories: 408,
fat: 3.2,
calcium: "0%"
},
{
name: "Donut",
calories: 452,
fat: 25.0,
calcium: "2%"
},
{
name: "KitKat",
calories: 518,
fat: 26.0,
calcium: "12%"
}
];
let data = [];
for (let i = 0; i < 1000; i++) {
data.push(...[...seed]);
}
data.forEach((row, index) => {
row.index = index;
});
new Vue({
el: "#q-app",
data: {
columns,
data,
pagination: {
rowsPerPage: 0
}
}
});
</script>
</body>
</html>
To enable pagination, we set rowsPerPage to a number bigger than 0:
<!DOCTYPE html>
<html>
<head>
<link
href="https://fonts.googleapis.com/css?family=Roboto:100,300,400,500,700,900|Material+Icons"
rel="stylesheet"
type="text/css"
/>
<link
href="https://cdn.jsdelivr.net/npm/quasar@1.12.13/dist/quasar.min.css"
rel="stylesheet"
type="text/css"
/>
</head>
<body class="body--dark">
<script src="https://cdn.jsdelivr.net/npm/vue@^2.0.0/dist/vue.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/quasar@1.12.13/dist/quasar.umd.min.js"></script>
<div id="q-app">
<q-layout
view="lHh Lpr lFf"
container
style="height: 100vh;"
class="shadow-2 rounded-borders"
>
<div class="q-pa-md">
<q-table
style="height: 400px;"
title="Treats"
:data="data"
:columns="columns"
row-key="index"
virtual-scroll
:pagination.sync="pagination"
:rows-per-page-options="[0]"
>
</q-table>
</div>
</q-layout>
</div>
<script>
const columns = [
{
name: "name",
required: true,
label: "Dessert",
align: "left",
field: (row) => row.name,
format: (val) => `${val}`,
sortable: true
},
{
name: "calories",
align: "center",
label: "Calories",
field: "calories",
sortable: true
},
{ name: "fat", label: "Fat (g)", field: "fat", sortable: true },
{
name: "calcium",
label: "Calcium (%)",
field: "calcium",
sortable: true,
sort: (a, b) => parseInt(a, 10) - parseInt(b, 10)
}
];
const seed = [
{
name: "Frozen Yogurt",
calories: 159,
fat: 6.0,
calcium: "14%"
},
{
name: "Ice cream sandwich",
calories: 237,
fat: 9.0,
calcium: "8%"
},
{
name: "Eclair",
calories: 262,
fat: 16.0,
calcium: "6%"
},
{
name: "Honeycomb",
calories: 408,
fat: 3.2,
calcium: "0%"
},
{
name: "Donut",
calories: 452,
fat: 25.0,
calcium: "2%"
},
{
name: "KitKat",
calories: 518,
fat: 26.0,
calcium: "12%"
}
];
let data = [];
for (let i = 0; i < 1000; i++) {
data.push(...[...seed]);
}
data.forEach((row, index) => {
row.index = index;
});
new Vue({
el: "#q-app",
data: {
columns,
data,
pagination: {
rowsPerPage: 1000
}
}
});
</script>
</body>
</html>
Multiple Rows for a Data Row
We can customize the rows by populating the header and body slots.
For instance, we can write:
<!DOCTYPE html>
<html>
<head>
<link
href="https://fonts.googleapis.com/css?family=Roboto:100,300,400,500,700,900|Material+Icons"
rel="stylesheet"
type="text/css"
/>
<link
href="https://cdn.jsdelivr.net/npm/quasar@1.12.13/dist/quasar.min.css"
rel="stylesheet"
type="text/css"
/>
</head>
<body class="body--dark">
<script src="https://cdn.jsdelivr.net/npm/vue@^2.0.0/dist/vue.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/quasar@1.12.13/dist/quasar.umd.min.js"></script>
<div id="q-app">
<q-layout
view="lHh Lpr lFf"
container
style="height: 100vh;"
class="shadow-2 rounded-borders"
>
<div class="q-pa-md">
<q-table
style="height: 400px;"
title="Treats"
:data="data"
:columns="columns"
row-key="index"
virtual-scroll
:pagination.sync="pagination"
:rows-per-page-options="[0]"
>
<template v-slot:header="props">
<q-tr :props="props">
<q-th></q-th>
<q-th v-for="col in props.cols" :key="col.name" :props="props">
{{ col.label }}
</q-th>
</q-tr>
</template>
<template v-slot:body="props">
<q-tr :props="props" :key="`m_${props.row.index}`">
<q-td>
Name: {{ props.row.name }}
</q-td>
<q-td v-for="col in props.cols" :key="col.name" :props="props">
{{ col.value }}
</q-td>
</q-tr>
<q-tr
:props="props"
:key="`e_${props.row.index}`"
class="q-virtual-scroll--with-prev"
>
<q-td colspan="100%">
<div class="text-left">
This is the second row generated from the same data: {{
props.row.name }}
</div>
</q-td>
</q-tr>
</template>
</q-table>
</div>
</q-layout>
</div>
<script>
const columns = [
{
name: "name",
required: true,
label: "Dessert",
align: "left",
field: (row) => row.name,
format: (val) => `${val}`,
sortable: true
},
{
name: "calories",
align: "center",
label: "Calories",
field: "calories",
sortable: true
},
{ name: "fat", label: "Fat (g)", field: "fat", sortable: true },
{
name: "calcium",
label: "Calcium (%)",
field: "calcium",
sortable: true,
sort: (a, b) => parseInt(a, 10) - parseInt(b, 10)
}
];
const data = [
{
name: "Frozen Yogurt",
calories: 159,
fat: 6.0,
calcium: "14%"
},
{
name: "Ice cream sandwich",
calories: 237,
fat: 9.0,
calcium: "8%"
},
{
name: "Eclair",
calories: 262,
fat: 16.0,
calcium: "6%"
},
{
name: "Honeycomb",
calories: 408,
fat: 3.2,
calcium: "0%"
},
{
name: "Donut",
calories: 452,
fat: 25.0,
calcium: "2%"
},
{
name: "KitKat",
calories: 518,
fat: 26.0,
calcium: "12%"
}
];
new Vue({
el: "#q-app",
data: {
columns,
data,
pagination: {
rowsPerPage: 1000
}
}
});
</script>
</body>
</html>
We populate the body slot with the table cell data.
We add another tr to display whatever data in the 2nd row.
And the header slot has the table header cells.
Conclusion
We can add virtual scrolling and customize the row display with Quasat’s q-table component.