67 lines
2.6 KiB
JavaScript
67 lines
2.6 KiB
JavaScript
/*
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* Copyright 2020 Google LLC
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* https://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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import { bindReporter } from './lib/bindReporter.js';
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import { getVisibilityWatcher } from './lib/getVisibilityWatcher.js';
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import { initMetric } from './lib/initMetric.js';
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import { observe } from './lib/observe.js';
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import { onBFCacheRestore } from './lib/onBFCacheRestore.js';
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import { onHidden } from './lib/onHidden.js';
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import { firstInputPolyfill, resetFirstInputPolyfill } from './lib/polyfills/firstInputPolyfill.js';
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export const getFID = (onReport, reportAllChanges) => {
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const visibilityWatcher = getVisibilityWatcher();
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let metric = initMetric('FID');
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let report;
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const entryHandler = (entry) => {
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// Only report if the page wasn't hidden prior to the first input.
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if (entry.startTime < visibilityWatcher.firstHiddenTime) {
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metric.value = entry.processingStart - entry.startTime;
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metric.entries.push(entry);
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report(true);
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}
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};
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const po = observe('first-input', entryHandler);
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report = bindReporter(onReport, metric, reportAllChanges);
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if (po) {
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onHidden(() => {
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po.takeRecords().map(entryHandler);
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po.disconnect();
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}, true);
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}
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if (window.__WEB_VITALS_POLYFILL__) {
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// Prefer the native implementation if available,
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if (!po) {
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window.webVitals.firstInputPolyfill(entryHandler);
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}
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onBFCacheRestore(() => {
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metric = initMetric('FID');
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report = bindReporter(onReport, metric, reportAllChanges);
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window.webVitals.resetFirstInputPolyfill();
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window.webVitals.firstInputPolyfill(entryHandler);
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});
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}
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else {
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// Only monitor bfcache restores if the browser supports FID natively.
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if (po) {
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onBFCacheRestore(() => {
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metric = initMetric('FID');
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report = bindReporter(onReport, metric, reportAllChanges);
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resetFirstInputPolyfill();
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firstInputPolyfill(entryHandler);
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});
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}
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}
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};
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