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| 1 | +// This script is a localized version of the upstream |
| 2 | +// https://github.com/pastelsky/network-idle-callback |
| 3 | +// which fixes isssues with browser importing of the |
| 4 | +// above dependency. It is hopefully temporary. |
| 5 | + |
| 6 | +const DOMContentLoad = new Promise(resolve => { |
| 7 | + document.addEventListener('DOMContentLoaded', resolve); |
| 8 | +}); |
| 9 | + |
| 10 | +navigator.serviceWorker.getRegistration() |
| 11 | + .then(registration => { |
| 12 | + if (!registration) { |
| 13 | + console.warn('`networkIdleCallback` was called before a service worker was registered.'); |
| 14 | + console.warn('`networkIdleCallback` is ineffective without a working service worker'); |
| 15 | + } |
| 16 | + }); |
| 17 | + |
| 18 | +/** |
| 19 | + * networkIdleCallback works similar to requestIdleCallback, |
| 20 | + * detecting and notifying you when network activity goes idle |
| 21 | + * in your current tab. |
| 22 | + * @param {*} fn - A valid function |
| 23 | + * @param {*} options - An options object |
| 24 | + */ |
| 25 | +function networkIdleCallback(fn, options = {timeout: 0}) { |
| 26 | + // Call the function immediately if required features are absent |
| 27 | + if ( |
| 28 | + !'MessageChannel' in window || |
| 29 | + !'serviceWorker' in navigator || |
| 30 | + !navigator.serviceWorker.controller |
| 31 | + ) { |
| 32 | + DOMContentLoad.then(() => fn({didTimeout: false})); |
| 33 | + return; |
| 34 | + } |
| 35 | + |
| 36 | + const messageChannel = new MessageChannel(); |
| 37 | + navigator.serviceWorker.controller |
| 38 | + .postMessage( |
| 39 | + 'NETWORK_IDLE_ENQUIRY', |
| 40 | + [messageChannel.port2], |
| 41 | + ); |
| 42 | + |
| 43 | + const timeoutId = setTimeout(() => { |
| 44 | + const cbToPop = networkIdleCallback.__callbacks__ |
| 45 | + .find(cb => cb.id === timeoutId); |
| 46 | + |
| 47 | + networkIdleCallback.__popCallback__(cbToPop, true); |
| 48 | + }, options.timeout); |
| 49 | + |
| 50 | + networkIdleCallback.__callbacks__.push({ |
| 51 | + id: timeoutId, |
| 52 | + fn, |
| 53 | + timeout: options.timeout, |
| 54 | + }); |
| 55 | + |
| 56 | + messageChannel.port1.addEventListener('message', handleMessage); |
| 57 | + messageChannel.port1.start(); |
| 58 | +} |
| 59 | + |
| 60 | +/* |
| 61 | +function cancelNetworkIdleCallback(callbackId) { |
| 62 | + clearTimeout(callbackId); |
| 63 | +
|
| 64 | + networkIdleCallback.__callbacks__ = networkIdleCallback.__callbacks__ |
| 65 | + .find(cb => cb.id === callbackId); |
| 66 | +} |
| 67 | +*/ |
| 68 | + |
| 69 | +networkIdleCallback.__popCallback__ = (callback, didTimeout) => { |
| 70 | + DOMContentLoad.then(() => { |
| 71 | + const cbToPop = networkIdleCallback.__callbacks__ |
| 72 | + .find(cb => cb.id === callback.id); |
| 73 | + |
| 74 | + if (cbToPop) { |
| 75 | + cbToPop.fn({didTimeout}); |
| 76 | + clearTimeout(cbToPop.id); |
| 77 | + networkIdleCallback.__callbacks__ = networkIdleCallback.__callbacks__.filter( |
| 78 | + cb => cb.id !== callback.id); |
| 79 | + } |
| 80 | + }); |
| 81 | +}; |
| 82 | + |
| 83 | +networkIdleCallback.__callbacks__ = []; |
| 84 | + |
| 85 | +if ('serviceWorker' in navigator) { |
| 86 | + navigator.serviceWorker.addEventListener('message', handleMessage); |
| 87 | +} |
| 88 | + |
| 89 | +/** |
| 90 | + * Handle message passing |
| 91 | + * @param {*} event - A valid event |
| 92 | + */ |
| 93 | +function handleMessage(event) { |
| 94 | + if (!event.data) { |
| 95 | + return; |
| 96 | + } |
| 97 | + |
| 98 | + switch (event.data) { |
| 99 | + case 'NETWORK_IDLE_ENQUIRY_RESULT_IDLE': |
| 100 | + case 'NETWORK_IDLE_CALLBACK': |
| 101 | + networkIdleCallback.__callbacks__.forEach(callback => { |
| 102 | + networkIdleCallback.__popCallback__(callback, false); |
| 103 | + }); |
| 104 | + break; |
| 105 | + } |
| 106 | +} |
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