314 lines
13 KiB
Vue
314 lines
13 KiB
Vue
<template>
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<DocSectionText v-bind="$attrs">
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<p>When lazy loading is enabled via the <i>virtualScrollerOptions</i>, data is fetched on demand during scrolling instead of preload.</p>
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<p>In sample below, an in-memory list and timeout is used to mimic fetching from a remote datasource. The <i>virtualCars</i> is an empty array that is populated on scroll.</p>
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</DocSectionText>
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<DeferredDemo @load="loadDemoData">
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<div class="card">
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<DataTable
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:value="virtualCars"
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scrollable
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scrollHeight="400px"
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:virtualScrollerOptions="{ lazy: true, onLazyLoad: loadCarsLazy, itemSize: 46, delay: 200, showLoader: true, loading: lazyLoading, numToleratedItems: 10 }"
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tableStyle="min-width: 50rem"
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>
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<Column field="id" header="Id" style="width: 20%">
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<template #loading>
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<div class="flex align-items-center" :style="{ height: '17px', 'flex-grow': '1', overflow: 'hidden' }">
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<Skeleton width="60%" height="1rem" />
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</div>
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</template>
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</Column>
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<Column field="vin" header="Vin" style="width: 20%">
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<template #loading>
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<div class="flex align-items-center" :style="{ height: '17px', 'flex-grow': '1', overflow: 'hidden' }">
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<Skeleton width="40%" height="1rem" />
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</div>
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</template>
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</Column>
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<Column field="year" header="Year" style="width: 20%">
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<template #loading>
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<div class="flex align-items-center" :style="{ height: '17px', 'flex-grow': '1', overflow: 'hidden' }">
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<Skeleton width="30%" height="1rem" />
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</div>
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</template>
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</Column>
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<Column field="brand" header="Brand" style="width: 20%">
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<template #loading>
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<div class="flex align-items-center" :style="{ height: '17px', 'flex-grow': '1', overflow: 'hidden' }">
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<Skeleton width="40%" height="1rem" />
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</div>
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</template>
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</Column>
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<Column field="color" header="Color" style="width: 20%">
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<template #loading>
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<div class="flex align-items-center" :style="{ height: '17px', 'flex-grow': '1', overflow: 'hidden' }">
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<Skeleton width="60%" height="1rem" />
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</div>
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</template>
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</Column>
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</DataTable>
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</div>
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</DeferredDemo>
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<DocSectionCode :code="code" :service="['CarService']" />
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</template>
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<script>
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import { CarService } from '@/service/CarService';
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export default {
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data() {
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return {
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cars: null,
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virtualCars: Array.from({ length: 100000 }),
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lazyLoading: false,
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loadLazyTimeout: null,
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code: {
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basic: `
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<DataTable :value="virtualCars" scrollable scrollHeight="400px" tableStyle="min-width: 50rem"
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:virtualScrollerOptions="{ lazy: true, onLazyLoad: loadCarsLazy, itemSize: 46, delay: 200, showLoader: true, loading: lazyLoading, numToleratedItems: 10 }">
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<Column field="id" header="Id" style="width: 20%">
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<template #loading>
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<div class="flex align-items-center" :style="{ height: '17px', 'flex-grow': '1', overflow: 'hidden' }">
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<Skeleton width="60%" height="1rem" />
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</div>
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</template>
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</Column>
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<Column field="vin" header="Vin" style="width: 20%">
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<template #loading>
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<div class="flex align-items-center" :style="{ height: '17px', 'flex-grow': '1', overflow: 'hidden' }">
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<Skeleton width="40%" height="1rem" />
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</div>
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</template>
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</Column>
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<Column field="year" header="Year" style="width: 20%">
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<template #loading>
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<div class="flex align-items-center" :style="{ height: '17px', 'flex-grow': '1', overflow: 'hidden' }">
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<Skeleton width="30%" height="1rem" />
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</div>
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</template>
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</Column>
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<Column field="brand" header="Brand" style="width: 20%">
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<template #loading>
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<div class="flex align-items-center" :style="{ height: '17px', 'flex-grow': '1', overflow: 'hidden' }">
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<Skeleton width="40%" height="1rem" />
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</div>
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</template>
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</Column>
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<Column field="color" header="Color" style="width: 20%">
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<template #loading>
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<div class="flex align-items-center" :style="{ height: '17px', 'flex-grow': '1', overflow: 'hidden' }">
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<Skeleton width="60%" height="1rem" />
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</div>
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</template>
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</Column>
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</DataTable>
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`,
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options: `
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<template>
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<div class="card">
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<DataTable :value="virtualCars" scrollable scrollHeight="400px" tableStyle="min-width: 50rem"
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:virtualScrollerOptions="{ lazy: true, onLazyLoad: loadCarsLazy, itemSize: 46, delay: 200, showLoader: true, loading: lazyLoading, numToleratedItems: 10 }">
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<Column field="id" header="Id" style="width: 20%">
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<template #loading>
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<div class="flex align-items-center" :style="{ height: '17px', 'flex-grow': '1', overflow: 'hidden' }">
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<Skeleton width="60%" height="1rem" />
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</div>
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</template>
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</Column>
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<Column field="vin" header="Vin" style="width: 20%">
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<template #loading>
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<div class="flex align-items-center" :style="{ height: '17px', 'flex-grow': '1', overflow: 'hidden' }">
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<Skeleton width="40%" height="1rem" />
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</div>
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</template>
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</Column>
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<Column field="year" header="Year" style="width: 20%">
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<template #loading>
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<div class="flex align-items-center" :style="{ height: '17px', 'flex-grow': '1', overflow: 'hidden' }">
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<Skeleton width="30%" height="1rem" />
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</div>
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</template>
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</Column>
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<Column field="brand" header="Brand" style="width: 20%">
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<template #loading>
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<div class="flex align-items-center" :style="{ height: '17px', 'flex-grow': '1', overflow: 'hidden' }">
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<Skeleton width="40%" height="1rem" />
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</div>
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</template>
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</Column>
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<Column field="color" header="Color" style="width: 20%">
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<template #loading>
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<div class="flex align-items-center" :style="{ height: '17px', 'flex-grow': '1', overflow: 'hidden' }">
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<Skeleton width="60%" height="1rem" />
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</div>
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</template>
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</Column>
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</DataTable>
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</div>
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</template>
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<script>
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import { CarService } from '@/service/CarService';
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export default {
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data() {
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return {
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cars: null,
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virtualCars: Array.from({ length: 100000 }),
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lazyLoading: false,
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loadLazyTimeout: null
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};
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},
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mounted() {
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this.cars = Array.from({ length: 100000 }).map((_, i) => CarService.generateCar(i + 1));
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},
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methods: {
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loadCarsLazy(event) {
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!this.lazyLoading && (this.lazyLoading = true);
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if (this.loadLazyTimeout) {
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clearTimeout(this.loadLazyTimeout);
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}
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//simulate remote connection with a timeout
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this.loadLazyTimeout = setTimeout(() => {
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let _virtualCars = [...this.virtualCars];
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let { first, last } = event;
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//load data of required page
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const loadedCars = this.cars.slice(first, last);
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//populate page of virtual cars
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Array.prototype.splice.apply(_virtualCars, [...[first, last - first], ...loadedCars]);
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this.virtualCars = _virtualCars;
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this.lazyLoading = false;
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}, Math.random() * 1000 + 250);
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}
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}
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};
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<\/script>
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`,
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composition: `
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<template>
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<div class="card">
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<DataTable :value="virtualCars" scrollable scrollHeight="400px" tableStyle="min-width: 50rem"
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:virtualScrollerOptions="{ lazy: true, onLazyLoad: loadCarsLazy, itemSize: 46, delay: 200, showLoader: true, loading: lazyLoading, numToleratedItems: 10 }">
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<Column field="id" header="Id" style="width: 20%">
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<template #loading>
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<div class="flex align-items-center" :style="{ height: '17px', 'flex-grow': '1', overflow: 'hidden' }">
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<Skeleton width="60%" height="1rem" />
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</div>
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</template>
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</Column>
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<Column field="vin" header="Vin" style="width: 20%">
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<template #loading>
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<div class="flex align-items-center" :style="{ height: '17px', 'flex-grow': '1', overflow: 'hidden' }">
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<Skeleton width="40%" height="1rem" />
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</div>
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</template>
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</Column>
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<Column field="year" header="Year" style="width: 20%">
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<template #loading>
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<div class="flex align-items-center" :style="{ height: '17px', 'flex-grow': '1', overflow: 'hidden' }">
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<Skeleton width="30%" height="1rem" />
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</div>
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</template>
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</Column>
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<Column field="brand" header="Brand" style="width: 20%">
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<template #loading>
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<div class="flex align-items-center" :style="{ height: '17px', 'flex-grow': '1', overflow: 'hidden' }">
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<Skeleton width="40%" height="1rem" />
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</div>
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</template>
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</Column>
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<Column field="color" header="Color" style="width: 20%">
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<template #loading>
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<div class="flex align-items-center" :style="{ height: '17px', 'flex-grow': '1', overflow: 'hidden' }">
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<Skeleton width="60%" height="1rem" />
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</div>
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</template>
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</Column>
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</DataTable>
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</div>
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</template>
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<script setup>
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import { ref, onMounted } from 'vue';
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import { CarService } from '@/service/CarService';
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onMounted(() => {
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cars.value = Array.from({ length: 100000 }).map((_, i) => CarService.generateCar(i + 1));
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});
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const cars = ref();
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const virtualCars = ref(Array.from({ length: 100000 }));
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const lazyLoading = ref(false);
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const loadLazyTimeout = ref();
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const loadCarsLazy = (event) => {
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!lazyLoading.value && (lazyLoading.value = true);
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if (loadLazyTimeout.value) {
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clearTimeout(loadLazyTimeout.value);
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}
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//simulate remote connection with a timeout
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loadLazyTimeout.value = setTimeout(() => {
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let _virtualCars = [...virtualCars.value];
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let { first, last } = event;
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//load data of required page
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const loadedCars = cars.value.slice(first, last);
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//populate page of virtual cars
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Array.prototype.splice.apply(_virtualCars, [...[first, last - first], ...loadedCars]);
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virtualCars.value = _virtualCars;
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lazyLoading.value = false;
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}, Math.random() * 1000 + 250);
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};
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<\/script>
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`,
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data: `
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{
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id: 1
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vin: tvACo,
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brand: Norma,
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color: Black,
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year: 2002
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}`
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}
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};
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},
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methods: {
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loadDemoData() {
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this.cars = Array.from({ length: 100000 }).map((_, i) => CarService.generateCar(i + 1));
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},
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loadCarsLazy(event) {
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!this.lazyLoading && (this.lazyLoading = true);
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if (this.loadLazyTimeout) {
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clearTimeout(this.loadLazyTimeout);
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}
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//simulate remote connection with a timeout
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this.loadLazyTimeout = setTimeout(() => {
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let _virtualCars = [...this.virtualCars];
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let { first, last } = event;
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//load data of required page
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const loadedCars = this.cars.slice(first, last);
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//populate page of virtual cars
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Array.prototype.splice.apply(_virtualCars, [...[first, last - first], ...loadedCars]);
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this.virtualCars = _virtualCars;
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this.lazyLoading = false;
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}, Math.random() * 1000 + 250);
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}
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}
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};
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</script>
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