From a7faa6bb6591622207a8d89610b5e9c8b53eca30 Mon Sep 17 00:00:00 2001 From: George Kalpakas Date: Sat, 13 Jun 2020 10:55:54 +0300 Subject: [PATCH] docs(service-worker): minor fixes/improvements in the SW Communication guide (#37555) This commit includes various fixes/improvements for the "Service worker communication" guide. This partially addresses #37527. PR Close #37555 --- .../guide/service-worker-communications.md | 22 ++++++++++++------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/aio/content/guide/service-worker-communications.md b/aio/content/guide/service-worker-communications.md index 28c428c42c..384803216b 100644 --- a/aio/content/guide/service-worker-communications.md +++ b/aio/content/guide/service-worker-communications.md @@ -31,26 +31,27 @@ You can use these events to notify the user of a pending update or to refresh th ### Checking for updates -It's possible to ask the service worker to check if any updates have been deployed to the server. You might choose to do this if you have a site that changes frequently or want updates to happen on a schedule. +It's possible to ask the service worker to check if any updates have been deployed to the server. +The service worker checks for updates during initialization and on each navigation request—that is, when the user navigates from a different address to your app. +However, you might choose to manually check for updates if you have a site that changes frequently or want updates to happen on a schedule. Do this with the `checkForUpdate()` method: - This method returns a `Promise` which indicates that the update check has completed successfully, though it does not indicate whether an update was discovered as a result of the check. Even if one is found, the service worker must still successfully download the changed files, which can fail. If successful, the `available` event will indicate availability of a new version of the app.
-In order to avoid negatively affecting the initial rendering of the page, `ServiceWorkerModule` will by default wait for up to 30 seconds for the app to stabilize, before registering the ServiceWorker script. -Constantly polling for updates, e.g. with [setInterval()](https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/setInterval) or RxJS' [interval()](https://rxjs.dev/api/index/function/interval), will prevent the app from stabilizing and the ServiceWorker script will not be registered with the browser until the 30 seconds upper limit is reached. - -You can avoid that by waiting for the app to stabilize first, before starting to poll for updates -(as shown in the example above). +In order to avoid negatively affecting the initial rendering of the page, `ServiceWorkerModule` waits for up to 30 seconds by default for the app to stabilize, before registering the ServiceWorker script. +Constantly polling for updates, for example, with [setInterval()](https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/setInterval) or RxJS' [interval()](https://rxjs.dev/api/index/function/interval), will prevent the app from stabilizing and the ServiceWorker script will not be registered with the browser until the 30 seconds upper limit is reached. Note that this is true for any kind of polling done by your application. Check the {@link ApplicationRef#isStable isStable} documentation for more information. +You can avoid that delay by waiting for the app to stabilize first, before starting to poll for updates, as shown in the example above. +Alternatively, you might want to define a different {@link SwRegistrationOptions#registrationStrategy registration strategy} for the ServiceWorker. +
### Forcing update activation @@ -59,7 +60,12 @@ If the current tab needs to be updated to the latest app version immediately, it -Doing this could break lazy-loading in currently running apps, especially if the lazy-loaded chunks use filenames with hashes, which change every version. +
+ +Calling `activateUpdate()` without reloading the page could break lazy-loading in a currently running app, especially if the lazy-loaded chunks use filenames with hashes, which change every version. +Therefore, it is recommended to reload the page once the promise returned by `activateUpdate()` is resolved. + +
## More on Angular service workers