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// Recording events
const params = new URLSearchParams(window.location.search);
const uuid = params.get('uuid');
// The recorded events are stored in localStorage rather than global variables
// to catch events fired just before navigating out.
function getPushedItems(key) {
return JSON.parse(localStorage.getItem(key) || '[]');
}
function pushItem(key, value) {
const array = getPushedItems(key);
array.push(value);
localStorage.setItem(key, JSON.stringify(array));
}
window.recordEvent = function(eventName) {
pushItem(uuid + '.observedEvents', eventName);
}
window.getRecordedEvents = function() {
return getPushedItems(uuid + '.observedEvents');
}
// Records events fired on `window` and `document`, with names listed in
// `eventNames`.
function startRecordingEvents(eventNames) {
for (const eventName of eventNames) {
window.addEventListener(eventName, event => {
let result = eventName;
if (event.persisted) {
result += '.persisted';
}
if (eventName === 'visibilitychange') {
result += '.' + document.visibilityState;
}
recordEvent('window.' + result);
});
document.addEventListener(eventName, () => {
let result = eventName;
if (eventName === 'visibilitychange') {
result += '.' + document.visibilityState;
}
recordEvent('document.' + result);
});
}
}
// When a comma-separated list of event names are given as the `events`
// parameter in the URL, start record the events of the given names.
if (params.get('events')) {
startRecordingEvents(params.get('events').split(','));
}