I have a demo app which is supposed to be an example of creating an offline APP that works on mobile devices. I have created a manifest file and am serving it with the correct MIME type, but the main image in the app is always fetched online and if I go to airplane mode, the image doesn't load despite being in the cache.
Why is the image not in the offline cache?
Update
I now have a valid app cache manifest, but on the iPhone I randomly don't get the main image still - even when online. I have a manual refresh button that normally gets the image on the second or third attempt, but when I open the app from the home screen it has a '?' placeholder instead.
Update
I have simplified the example a lot and incorporated lots of suggestions, but still have the problem. Here are the steps I have tried so far.
Removed the JavaScript entirely - the page just displays a static image
Replaced all images with files less than 25kb
Added a NETWORK: * to the manifest
Moved NETWORK: * to be above the CACHE: header.
Tried renaming "manifest.appcache" to "cache.manifest"
It works in Firefox in offline mode with the disk cache empty (i.e. to ensure it can only use offline cache!) but still shows the dreaded blue question mark on IOS (tested on iPhone 4s).
It seems like your cache file is invalid due to missing files. Try making your paths relative e.g. Puzzle/page.png.
Running the validator gives the below errors:
Line 3: Resource not found
http://www.stevefenton.co.uk/Puzzle/CACHE
Line 4: Resource not found
http://www.stevefenton.co.uk/index.html
Line 5: Resource not found
http://www.stevefenton.co.uk/apple-touch-icon.png
Line 6: Resource not found
http://www.stevefenton.co.uk/page.png
Line 7: Resource not found
http://www.stevefenton.co.uk/knight.png
Line 10: Resource not found
http://www.stevefenton.co.uk/style.css
After a great deal of trial and error I can confirm that I have solved the issue.
The answer is strange, but I have double checked to ensure that making this change alone causes the issue to appear / disappear.
The following meta-tag is normally recommended if your app is going to be added to the IOS home screen:
<meta name="apple-mobile-web-app-capable" content="yes">
But actually, don't add this. Removing this tag from my demo app fixed the problem instantly on IOS 5.1.1 - so you need to decide whether you MUST have offline cache or if you MUST have full-screen style, rather than running in Safari.
Related
I have a Hybrid app I rebuilt after setting the Target Android version to API 30, per a new warning that Google now requires this, and am trying it on a Tablet with Android 11. Originally following an old hybrid sample app, my app copies files from the resources to the file system. This seems to work, as no exceptions are thrown from the File operations. The first thing it does is display a splash screen from an HTML file copied from the afore-mentioned resource copy, using the LoadHtml function of a created WebView, and giving it a URL formatted like this:
file:///data/data/com.mycompanyname.myappnameandroid/files/Content/Splash.html
LoadHtml doesn't throw an exception, but then the screen displays an error message referencing this path and the error "ERR_ACCESS_DENIED". This file does reference CSS files copied to the same directory (referenced like "<link rel="stylesheet" href="site.css" />
" in the HTML header). It will continue on to display the main app pages, but it apparently failed to load CSS files and so forth, as all the styling and scripting is missing. What do I need to change to make this work?
Searching, I find talk of "Scoped Storage", but I can't make any sense of it. I'm hoping there is a simple fix.
There is a simple fix. Add the following to your set up of the WebView:
webView.Settings.AllowFileAccess = true;
Apparently the default changed from true to false.
Thanks to this posting for the clue: Load file into webView with scoped storage
I have a Vue.js website with a PDF file which is included in my ultimate javascript bundle via webpack. (It's my CV.) The following build and delivery process has worked perfectly fine for me since 2017, but suddenly stopped working in iOS 14:
Build the PDF with LaTeX.
Use webpack's url-loader to include the PDF in my webpack bundle as a base64 data URI.
Load that URL into a vuex data store, and then just deliver it as a link when clicked.
For the last three years, this has worked fine: I've been able to click on the link and get a working PDF. It's been kind of random and platform-specific whether the PDF opens in-browser or shows up in a download folder, and whether it gets the filename I've asked it to get or not, but, well, that doesn't matter to me. And the core functionality of click the link and get the PDF has worked on every browser and every platform I've ever tried it on.
All of a sudden, with iOS 14, it's stopped working. Now, when I try to activate the PDF link in iOS Safari, nothing happens at all. When I do it in iOS Chrome, it produces a little popup claiming it downloaded a document, but nothing seems to actually be able to open the document. And when I do it in iOS DuckDuckGo, it just displays the base64 data URI in the address bar.
Interestingly, if I take the dataURI that DDG displays in the address bar and copy and paste it into Safari or Chrome on iOS, it actually displays my pdf. So the browsers still have the capacity to display a PDF from a data URI. It just doesn't want to do so from my link.
And my site still works as expected on the desktop. Including in Safari on the desktop. Also, it still works on my wife's phone (she's still on iOS 13). So this is clearly something Apple changed in iOS 14. But what? And how to get my site working again?
I'm guessing that Apple has changed the behavior of the renderer in iOS in some fashion to cause it to break across browsers but nowhere else (since browsers in iOS are all still required to rely on webkit, right?)
This is a pretty important feature to me. I made this decision deliberately for perceived performance---combined with pre-rendering, everything on my site, including the PDF, loads very close to instantly from the user perspective. So I'd really like to keep it.
I'm using Webpack 2.6.1 and Vue 2.3.3. This is a stable build that has been working flawlessly for three years, so I haven't felt the need to update anything except for security updates.
After searching around, I did find this Apple dev discussion which suggests that in iOS 14, Apple newly blocks redirects to data URIs. But I'm not doing a redirect, I'm actually navigating directly to the URI through a link. And the linked discussion suggests that the newly banned behavior just brings Apple in line with what other browsers already ban---but my code works in every other browser, so that can't be it.
Relevant code, to the extent it matters (though it's so basic and obvious that I doubt a simple code fix will be the answer here):
from my webpack.base.js:
{
test: /\.(pdf)$/,
loader: 'url-loader'
},
from my vuex store, in state.js
import cvURL from './assets/pdf/gowdercv.pdf';
from the component containing the link that points to PDF:
<p><a :href="cvURL" download="gowdercv.pdf"><img src="../../assets/icons/file-pdf.svg" class="cvicon"> Download in PDF</a></p>
which is loaded as a computed property to the component, i.e.,
computed: {
cvURL: function(){return this.$store.state.cvURL;},
Does anyone know how to get functionality back in iOS? Is there a workaround built in recent versions of webpack or vue for this? Thanks!
Update: after some help off SO, an acquaintance turned up this similar problem, which also came up with a solution: turning the base64 URI into a blob and passing that data url. Which also solves my problem. Though that SO doesn't have an accepted answer, so I can't vote to close my own question as a duplicate, alas.
So based on my searches this has been a long-standing bug on iOS/Apple’s end. As of yet I haven’t been able to confirm a workaround so would like to see if I’m up to speed on this.
I incorporated a new favicon on my site with the help of realfavicongenerator, and it’s showing up everywhere except Safari iOS where a faulty cache seems to force the old image to show when the site is favorited or bookmarked. Adding to homescreen works fine, MacOS favoriting/bookmarking works fine, Safari iOS doesn’t.
I remember having a similar issue when incorporating the first apple-touch-icon a few years ago, also using realfavicongenerator: when favoriting/bookmarking in Safari iOS the icon was empty instead of showing the image. Eventually it showed up but I don’t recall how or exacty when, but it definitely took a lot longer than it should have.
I’ve obviously tried clearing cache and website data/history through Safari settings, restarting my phone, appending a variable to the apple-touch-icon URL, using both absolute and relative paths, and tinkering with different image size specifications, none of which worked.
I saw a suggestion somewhere that resetting the phone may work, but my question in that scenario is what exactly to reset and whether this would compromise other data.
Are there any workarounds/fixes I’m not aware of?
I’m using an iPhone 7 with iOS 12.2. The code being used is straight from what realfavicongenerator provides.
RealFaviconGenerator's author speaking.
As you noticed, iOS Safari is quite lazy regarding favicon reloading. It is not the only one.
The trick is to force it to reload the icon by providing a URL it never encountered before. A simple way of doing this is to suffix the existing icon URL with a dummy parameter. For example, change /the_icon.png to /the_icon.png?v=2.
To do so with RealFaviconGenerator, generate your icons again. This time, make sure to open the Version/Refresh tab in the Favicon Generator Options panel, and select the second option, as below:
Note: You might want to edit manually the code already created by RealFaviconGenerator and append the version yourself. This might be a bad idea. For example, if you put your icons in your root folder, some HTML lines were not generated (because of conventions RFG is taking advantage of). But suddenly, these lines must be added to specify a version. This is definitely not something you can guess at first sight.
New favicon showed up today, with no intervention on my part (versioning had also been removed). Not sure why. Guess it may be due to a time interval.
I'm trying to setup a iPad app to work offline. I was able to successfully get it to work but I was told to put the app in multiple sub directories. When I did this and update the cache manifest file to the new destinations of all the files I kept getting an error that the site wouldn't work because it wasn't connected to the internet. I tried multiple paths and looked up different ideas but have come up empty handed. Is their a way to get offline mode working with a site inside sub directories?
Thanks.
This shouldn't make a difference. Make sure all urls in the manifest are relative and always end the manifest with:
NETWORK:
*
Furthermore make sure you don't forget to add any images, libraries etc. from the cached url's to the manifest. Sometimes even caps can make a difference. OPen the console of the developer tools in Chrome to see what's being cached and what breaks loading the appcache.
Also make sure there are no iframes (ie. like-buttons) on the homepage(page that includes the manifest attribute in the html-tag) which is always cached.
Little trick:
If you want to fallback you're homepage place the manifest attribute in an invisible iframe on the homepage of your app.
That way you have total control over what's cached and what not.
I'm making a website where a user can say which items he wants to cache. Based on this, a manifest file is generated. By doing this the user can still browse in the website when he is offline. This is all working fine in google chrome. But on iPad it's not working as it should.
Sometimes things get cached sometimes not, not even the pages i visited.
We have been testing with 2 iPads all morning, but we haven't been able to get the same result on both iPads. Even if we do exactly the same, we sometimes get different results.
So what we do:
turn WiFi on
browse to the website
make some settings so some pages/images/... are added to the manifest file
turn WiFi off
go back to safari refresh/browse to pages that should be cached.
Sometimes on one iPad (this is an iPad 1) it works exactly as it should, but sometimes it doesn't work at all.
On the other iPad (this is an iPad 2) it never works completely as it should. Just some random results.
It also looks like the results are different when we completely shutdown safari, and then clear the cache and then do the whole process of downloading and caching stuff...
Somebody can help me with this problem? It's a real pain in the ass at the moment... :(
Open web server (IIS)
Select website
Open MIME type
Add or edit to text/cache-manifest
Reset iis at command prompt iisreset
It works for me.
I've encountered some problems as well with ipad caching.
MIME type of the manifest file is not set right due to windows hosting. The standard MIME type on a windows server is "application/x-ms-manifest". This was created when the ClickOnce applications came to life. The MIME type that is necessary to work on safari is: "text/cache-manifest"
Cache size is too small on ipad (you should get a warning to enlarge it)
the Ipad needs time! I've noticed that the cache is not filled when you see all assets or when the website is "loaded". Give it twice the normal time to load before you place the website to your homescreen.
Cache of the cache :) The iPad only reloads the files when the modified date on the server is changed. So when you really want to test, clear all cache on the iPad, remove the link on the homescreen and upload all your files again.
Conclusion: Time consuming!
Hint: Turn on the debug console in safari on your desktop or iPad. It gives a fair idea if you did something wrong or if it is a cache problem on the iPad.
It looks like the problem didn't have anything to do with the application cache. It was somehow a problem with the cookies/the way i was dynamically building the manifest file.
I'd like to slightly echo Pieter-Paulus Vertongen, I had a similar experience with Windows hosting.
According to the debugging console in Safari, the mime type for the manifest file was being misread and nothing was being downloaded as a result.
I copied all of my files, including the .htaccess file, over to a linux server without changing any content within the files...and then the caching worked beautifully.
So yes, it's possible this may be an issue of where the files are hosted. Use the debugging console and Jonathan Stark's code to find out:
http://jonathanstark.com/blog/debugging-html-5-offline-application-cache?filename=2009/09/27/debugging-html-5-offline-application-cache/