We are experiencing a pwa application with services worker and everything that surrounds this theme.
I have questions about cache. Information is currently cached and accessed when offline. This works well when we talk about Android. In IOS it seems that the cache is not shared when we add the application to the home screen (installed). It seems that IOS keeps a cache for the application accessed in Safari and the installed one (I'm talking about the same application). In android it seems that the same cache is shared for the version installed and accessed in chrome.
In IOS after adding the home screen I am forced to log in online to generate the installed application cache.
About IOS would you like to know if you have already gone through this? And what would be the best way to persist this data so that the same cache is shared in the application accessed in Safari and the installed version.
In the service worker you mention the name of the cache, until and unless you change it there or update it e.g;
const staticCacheName = 'pages-cache-v3'; it will remain same and will be shared among versions. This may be true for the Android am not sure about IOS. Please update me if you have already found a better answer. Cheers:)
If this is still relevant, then I think that you should look at my answer in this question, because you are faced with the same problem.
PWAs on iOS 12 no longer shares Service Worker cache with Safari?
Related
As Apple announced Service Worker support for iOS 11.3 a few months ago, I recently started trying to get a service worker to work on iOS. On Safari it works as expected, after vising the website, it works offline. However, when trying to use the same feature in Chrome, I had intermittent results. Specifically, the service worker would only work every other page refresh, with the original refresh after going offline being one of the ones not working.
I know that Chrome on iOS is built on a version of Safari, therefore I am confused about this behavior.
Is this due to incomplete support from Chrome iOS for Service Workers? Because it is Chrome on iOS, I'm not sure of any easy way to debug it either, so any other tips to help track down the problem would be appreciated. Thank you!
Chrome for iOS do not support service workers currently(as of Apr-2020) and also the "Add to home screen" option is not available, if you are interested in that. Any offline page loading that you are experiencing should be from regular browser cache.
Here is an official documentation from Apple's web-kit page.
Update: A previous version of this post stated the Service Worker API
is available in all applications using WKWebView. At this time it is
only available in Safari, applications that use
SFSafariViewController, and web applications saved to your home
screen.
Notably, Chrome uses WKWebView as its browser engine in iOS, which don't have service worker support yet as per the above statement(which you can find in the link provided above). So the only way you can use Service worker in iOS is to use Safari browser or use one of the above supported web-views inside a native app.
Here is an article on what all PWA features iOS is still missing. Remember, this is a fast growing area. Always check if what is applicable now, especially if the documentation/article is getting older.
Here is an adapter to help debug in Chrome dev tools for pages loaded iOS - webkit/safari. Hope it becomes as easy as Android Chrome debugging one day!
Chrome for iOS is open source (https://blog.chromium.org/2017/01/open-sourcing-chrome-on-ios.html)
We can install the Chrome app with our developer signed certificate on an iOS device, launch the Chrome App, and start testing.
It is technically feasible.
As an update in January 2021: the official documentation from Apple's web-kit page still says the same thing, and I just battled a very difficult to debug issue in Chrome iOS - posting here in case it helps someone.
I had an iFrame containing a cross-origin Angular 10 PWA with Service Worker enabled, and the iFrame content would not show after an initial load - no errors, no server logs, just blank. The only solution that worked was to self-destruct the Service Worker per Angular's docs, and now the iFrame loads fine.
I have a PWA that I've been using perfectly till I updated my phone to 11.3 (introduce Service Workers supports, so in my iPhone it was only a bookmark) and all worked like a charm.
After I've updated to iOS 11.3 I wasn't able to enter to my app because I have an external login (in other domain) so each time I try to open my open this will open a safari browser to make the auth. Before PWA in iOS the external URLs were open in the same open (without open safari). Do you know if this is the correct behavior and, if it is ok, how can I fix it?
Thanks!
I managed to fix this by removing the manifest meta tag:
<link rel="manifest" href="/tracker/site.webmanifest">
My project is a simple PWA that uses Google's OAuth for login. I was getting redirected to Safari to login and unable to go back to the app (on my home screen). Hope it works for you too, I wasted 2 days trying to find a solution.
The reply by Anand tells me that offline capable PWAs need to implement service workers, since they are supported in 11.3 (or 11.4, not sure) and NOT manifests.
Anyways, this worked for me, hope it helps others as well.
When PWAs without service works(either your browser don't support it or your app don't have one) are added to home screen, its mere a bookmark. When the browser finds a SW, then it creates a package(like apk).
How to test this - Find a PWA site without service worker in android and add to home screen. When I tried it in one of Samsung device, it showed only "Remove" option and no uninstall option. When I added a PWA which had SW, got uninstall option. I was also able to locate the apk generated by Chrome when service worker is present.
Now on iOS - 3 possibilities I could think of.
1) My theory based on above behavior on PWAs with and without Service worker, your home icon create by iOS 11.2.x is a bookmark and the new version of safari is treating it as a bookmark to open it in browser. I couldn't test this as I've upgraded to 11.3 already and don't have a pre 11.3 PWA icon.
2) If you have reinstalled the icon(by removing and adding again to home screen) and still have the issue, its probably because your manifest file or service worker files have some issue/compatibility with Safari.
Since we don't have something like Lighthouse for safari, you can validate your manifest.json and service workers in Chrome Lighthouse.
3) Check on scope attribute in the manifest file to make sure you cover your entire domain you intent to cover. If you scope covers domain.com/myapp only, domain.com/otherapp will be opened in the browser when tried to open from any source.
It seems that with the last iOS version 11.4 this issue is solved, I think that now safari shares the context between the browser and the PWA and for example from PWA cookies can be accessed throw safari.
But I think there's still an issue when you open the PWA and you are being redirect to login (safari opens) once you're log in you stay in the browser (iOS does not return to the PWA, but this is a first step)
I want to be able to access folders and files via my app, the problem is, when i want to access files on the desktop, i have to run it from a server or at least to emulate one using a program like xampp.
I know PhoneGap has it's own API to access files, but i need to make the app work on desktop too, and i don't mind it to be as normal offline website ( via index.html, not an exe ), but i still need to solve the security issues, i can't tell clients to run it from a server...
The big idea after it, is that i need the app to check for new files in the server, if there are any, to download them.
Also, i want the app to be able to access those downloaded files when it is offline as well.
I guess using only phonegap in ios will solve this, but i still need it to work on windows desktop as well.
PhoneGap released PhoneGap Desktop
http://phonegap.com/blog/2014/12/11/phonegap-desktop-app-beta/
I think this is what you are looking for!
We developed an offline HTML5 web-app using the .manifest caching mechanism. Everything works as expectet.
Now some of our customers complain that after a long period of offline usage the cached data suddenly disappeared. It turns out - this is my guess - that iOS stores the cached files in its /CACHES/ directory, which, since iOS 5.0, can get purged if the device gets out of space. This can happen anytime, without even a warning to the user. Hence, the offline webapp is no longer running properly. The user has to reconnect the device to the internet and update the app.
For native Apps this problem is solved by storing the files in the /DOCUMENTS/ dir, using the flag 'do not backup' which prevents the files from being purged (since they don't sit in the /CACHES/ dir, and are not backed up to iCloud or iTunes.
See this link for details: http://www.marco.org/2011/10/13/ios5-caches-cleaning, however this does not say anything about HTML5 caching...
This one explains it again, however no solution: http://www.moneytoolkit.com/2012/04/apple-ios-html5-localstorage-is-broken/
Has anyone experienced the same? Is there a solution to this? The goal is to install a web-app once, and then run it without connection 'forever'...
Cheers, pawi
There is no way around this in Safari. A cache is never considered to be permanent.
If you have a UIWebView inside a native app, you can set WebKitStoreWebDataForBackup to YES in your user defaults. (iOS 6+ only)
I've been doing lots of work in getting a few web apps to work offline on iOS using the HTML5 manifest. I've ran across the typical problems everyone else has and fixed them and everything seems to be working fine—except in the case where I save the web app to the desktop on my iPhone 4.
If I do this and then enable airplane mode, I get the following alert when trying to access the app via the home screen: "your-app-name could not be opened because its not connected to the internet." Accessing the app via Safari browser works fine while offline.
If anyone knows if this is an error on my part, or even the slim possibility of a work around, do tell.
Even downloading the new Financial Times web app (very well done with extensive localStorage support) results in an error when accessing it offline from the home screen.
Technical specs: Running iPhone 4 with iOS 4.3.3 (but also saw the issue in 4.3.2)
After reading the comments (especially Rowan's) I ran more tests and found the answer:
No, Apple did not disable HTML5 offline capability for web apps saved to the home screen, it works - for the most part. There is a bug that will make it not work. It doesn't seem to have anything to do with your manifest setup (unless perhaps it downloaded a bad manifest or incomplete manifest at one point.) We don't know how widespread it is but the fix is to clear your Mobile Safari Cache.
Here's the steps:
Close the web app (make sure its not sticking around in the background).
Cleared Mobile Safari cache: Settings > Safari > Clear Cache
Reopened the app (for caching).
Close the web app again (make sure its not sticking around in the background).
Enabled "Airplane Mode": Settings > Airplane Mode
Reopened the app.
It should now work offline. If it doesn't then its probably a separate manifest issue in your app. Looks like a weird bug with the browser cache - or perhaps the cache was completely full? Who knows, but that's the answer. Thanks guys.
iOS seems to be very sensitive to load issues when offline.
I was getting your "could not be opened" error when offline on a page I was working on. The problem turned out to be that the page created an iframe pointing to a site that didn't have an AppCache. Removing those iframes fixed the issue.
In my case, I handled it using window.navigator.standalone which tells you whether you're running in an iOS homescreen app. The code looked like this:
if (!navigator.standalone) insertFrames();
add this to your html:
https://web.archive.org/web/20170201180939/https://jonathanstark.com/blog/debugging-html-5-offline-application-cache?filename=2009/09/27/debugging-html-5-offline-application-cache/
I found it massively useful - even though I've created my manifest file and compared it to other people's manifests this JavaScript debugging script gave me the clue I would have never found otherwise. I apparently had syntax error in my manifest ... long story short I had to remove everything and add the paths to each file/image one by one. The end result was the same however it worked... how weird!!! does whitespace / comments affect the syntax of the file?