Fallback to FileReader in iOS Chrome

[evgeniy-polyakov]

iOS 13 introduces "download" attribute but it behaves incorrectly in Chrome - the file is always open in same window. This pull request forces to use FileReader in iOS Chrome.

Also merged #578

[hwhelchel]

I'm seeing the same issue.

My use case is downloading short videos. On iOS these are quicktime / mov videos. In Safari 13 they download great using saveAs but in Chrome for iOS, Firefox for iOS, FB Messenger's browser it just opens the blob url in the same window and starts playing the video. I may be wrong, but I couldn't find a way to then download the video.

I spiked on testing the FileReader approach in Chrome for iOS. I was able to have it trigger a download in the browser but the file type wasn't present and the file name wasn't present. It was just called "download". Then it would let me navigate to the iPhone file system but the "Save" button was disabled so I was unable to persist the file.

@eligrey if @evgeniy-polyakov is able to fix the merge conflicts here, would you accept this PR? thanks all

[ts-23]

Fantastic work @evgeniy-polyakov, however in ios Chrome, it opens a new tab that defaults to a "document" file name. Is there some way to use a custom filename?

[eligrey]

I don't have immediate access to an iOS device. I'll test & merge this sometime next week 👍

[evgeniy-polyakov]

I don't have immediate access to an iOS device. I'll test & merge this sometime next week 👍

It seems to be already fixed in the original repository for all iOS browsers, not only Chrome. You use 'AppleWebKit' to test User Agent instead of 'CriOS':
https://chromium.googlesource.com/chromium/src.git/+/master/docs/ios/user_agent.md

I'm declining the pull request, no useful fixes here.

[evgeniy-polyakov]

I'm reopening the pull request. AppleWebKit is too wide, it also matches all modern desktop browsers on Win and MacOS platforms: https://deviceatlas.com/blog/list-of-user-agent-strings
So in the current version almost all desktop browsers fall back to FileReader that is inappropriate I guess. @eligrey please consider to merge this pull request or suggest another UA pattern that covers newest iOS devices.

[carlosperate]

I believe this issue is still present in iOS 14 with Chrome v87.
As it is, it works in Safari where the file downloads with the right filename, but in Chrome it opens the text content in the same tab.
Using this PR in chrome it downloads a file without filename or extension.