47 lines
1.8 KiB
JavaScript
47 lines
1.8 KiB
JavaScript
/*
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* Copyright 2022 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 { getLoadState } from '../lib/getLoadState.js';
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import { getSelector } from '../lib/getSelector.js';
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import { onFID as unattributedOnFID } from '../onFID.js';
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const attributeFID = (metric) => {
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const fidEntry = metric.entries[0];
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const attribution = {
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eventTarget: getSelector(fidEntry.target),
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eventType: fidEntry.name,
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eventTime: fidEntry.startTime,
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eventEntry: fidEntry,
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loadState: getLoadState(fidEntry.startTime),
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};
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// Use Object.assign to set property to keep tsc happy.
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const metricWithAttribution = Object.assign(metric, { attribution });
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return metricWithAttribution;
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};
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/**
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* Calculates the [FID](https://web.dev/articles/fid) value for the current page and
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* calls the `callback` function once the value is ready, along with the
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* relevant `first-input` performance entry used to determine the value. The
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* reported value is a `DOMHighResTimeStamp`.
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*
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* _**Important:** since FID is only reported after the user interacts with the
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* page, it's possible that it will not be reported for some page loads._
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*/
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export const onFID = (onReport, opts) => {
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unattributedOnFID((metric) => {
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const metricWithAttribution = attributeFID(metric);
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onReport(metricWithAttribution);
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}, opts);
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};
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