StorageManager has an API to make offline storages persistent which make them not to suffer from purging when there is not enough free space on user's drive. https://developer.mozilla.org/ru/docs/Web/API/StorageManager/persist
I want to use persistant offline storage for my website. Persistant mode can be activated using this code:
navigator.storage.persist.then(
function(persist_enabled) {console.log(persist_enabled)}
)
When this command is executed in Desktop FireFox version the browser prompts a permission and if a user allowed it persist_enabled is "true".
But when I run this command in Android Firefox version there is no permission prompt and the result is always "false".
Is there some condition I must to satisfy to turn this feature on on Adroid Firefox?
Update 2020.09.29
Firefox support team said that it is a bug. The permission prompt must be popped up but it's not. We should wait for a fix. https://github.com/mozilla-mobile/android-components/issues/3153
There are bad news for current date (checked on 9'th september 2020)
According to "Can i use" site (https://caniuse.com/mdn-api_storagemanager) this feature is not supported by default in Firefox 79 for Android. It must be enabled via internal configuration.
So it's not possible to use this feature for a regular site for now as users probably would not enable it.
Upd. 2020.12.11 There was a bug in Firefox for Android. The prompt should popup but it's not. Here is a related issue in github: https://github.com/mozilla-mobile/fenix/issues/14875 The problem is solved now.