iSharkFly-Docs
/
angular-docs-cn
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

docs(service-worker): describe safety-worker.js in SW guide (#21921) 

PR Close #21921
This commit is contained in:
Alex Rickabaugh 2018-01-30 14:08:23 -08:00 committed by Jason Aden
parent 7a20691f13
commit db3e65fb17
1 changed files with 24 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
aio/content/guide/service-worker-devops.md
View File

@ -290,20 +290,42 @@ out of date. Right click the Cache Storage title and refresh the caches.
Stopping and starting the service worker in the Service Worker Stopping and starting the service worker in the Service Worker
pane triggers a check for updates. pane triggers a check for updates.
## Fail-safe ## Service Worker Safety
Like any complex system, bugs or broken configurations can cause Like any complex system, bugs or broken configurations can cause
the Angular service worker to act in unforeseen ways. While its the Angular service worker to act in unforeseen ways. While its
design attempts to minimize the impact of such problems, the design attempts to minimize the impact of such problems, the
Angular service worker contains a failsafe mechanism in case Angular service worker contains several failsafe mechanisms in case
an administrator ever needs to deactivate the service worker quickly. an administrator ever needs to deactivate the service worker quickly.
## Fail-safe
To deactivate the service worker, remove or rename the To deactivate the service worker, remove or rename the
`ngsw-config.json` file. When the service worker's request `ngsw-config.json` file. When the service worker's request
for `ngsw.json` returns a `404`, then the service worker for `ngsw.json` returns a `404`, then the service worker
removes all of its caches and de-registers itself, removes all of its caches and de-registers itself,
essentially self-destructing. essentially self-destructing.
### Safety Worker
Also included in the `@angular/service-worker` NPM package is a small
script `safety-worker.js`, which when loaded will unregister itself
from the browser. This script can be used as a last resort to get rid
of unwanted service workers already installed on client pages.
It's important to note that you cannot register this worker directly,
as old clients with cached state may not see a new `index.html` which
installs the different worker script. Instead, you must serve the
contents of `safety-worker.js` at the URL of the Service Worker script
you are trying to unregister, and must continue to do so until you are
certain all users have successfully unregistered the old worker. For
most sites, this means that you should serve the safety worker at the
old Service Worker URL forever.
This script can be used both to deactivate `@angular/service-worker`
as well as any other Service Workers which might have been served in
the past on your site.
## More on Angular service workers ## More on Angular service workers
You may also be interested in the following: You may also be interested in the following: