SAF: App Inventor implementation of Storage Access Framework

[ChrisWard]

Don't get me wrong, your work on this extension is a masterpiece, small wonder that Evan wants you to integrate it into App Inventor.

I can suggest the examples you have already made. The issues:

1. Incomplete. SAF is baffling when you first see it, so examples should actually work stand-alone.
2. Old version Blocks used.
3. No introduction to the example describing what it's goal is.
4. Unattached Blocks
5. Anonymous inputs
6. Unreadable images

If you make more comprehensive examples, there wouldn't be so many posts from people asking what they have done wrong - including posts from fellow Power Users.

[ChrisWard]

Create a text file in an external folder of your choice from the Root Directory and write to it.

SAF_CreateTextFile.aia (31.8 KB)
Note: Add the SAF extension first! Can be tested on your device via Companion or as an APK.

[patel]

I tested your aia with companion, it runs well, I created file, how can I read it without selecting folder?

[ChrisWard]

As far as I know, you have to access the files by selecting the folder, this is how Google have designed the system to try to block hacking.

[Anke]

This is all you need to create a new text file in e.g. the folder /Documents:

[ChrisWard]

Actually if I leave the directory path blank, it defaults to the Downloads folder on my phone and I can't navigate from there, so starting specifically at the Root Folder (or any specific folder) is more reliable.

[Anke]

You cannot select

• the root dir of the external storage and
• also not /Download

using SAF.

[vknow360]

@patel

how can I read it without selecting folder?

You will have to pick the document at least once to get access to it. After getting uri you can read from file anytime.

[Anke]

@Anke

You cannot select

• the root dir of the external storage and
• also not /Download

using SAF

See also post #31

[ChrisWard]

@Anke

You cannot select

• the root dir of the external storage and
• also not /Download

using SAF

...... maybe you can't, but I have on Android 10.

[Anke]

@ChrisWard

but I have on Android 10

On Android < 11 SAF is not needed, because you can access all files (media & non-media) with storage permissions (in the external storage, outside the ASD), since AI2 decided to declare requestLegacyExternalStorage=true in the Manifest.

[Anke]

See also here:

Some basics on Android storage system

From an Android point of view there are an → Internal Storage and an → External Storage . 1. Internal Storage The Internal Storage can only be accessed with a rooted device. 1.1 The app package is saved in /data/data/<packageName>/ In order to be able to debug your app, AI2 saves the assets for → Companion on devices with Android ≥ 10 (API ≥ 29): /storage/emulated/0/Android/data/edu.mit.appinventor.aicompanion3/files/assets/ Android < 10 : /storage/emulated/0/Android/data/edu.mit…

[ChrisWard]

@Anke

On Android < 11 SAF is not needed, because you can access all files (media & non-media) with storage permissions (in the external storage, outside the ASD), since AI2 decided to declare requestLegacyExternalStorage=true in the Manifest.

Well, SAF came into being @ Android 4.4, but the purpose of my post was to present a fully working example App, presented in a way that people can actually understand.

[Anke]

@ChrisWard

SAF came into being @ Android 4.4

Yes, so what ...?

@ChrisWard

the purpose of my post was to present a fully working example App, presented in a way that people can actually understand

I'm not so sure if people actually understand it. Especially since it is / remains unclear why a text file should be created using SAF if it works without any problems with the File component (or without storage permissions on Android 11+ with my MFile extension), also on Android 11+ (at least for the Shared folders).

[ChrisWard]

@Anke

Especially since it is / remains unclear why a text file should be created using

I'm not sure you understand Anke

[Anke]

@ChrisWard As Sunny rightly said, explain a specific use case.

@vknow360

I can provide examples only if I know the use scenarios.

As soon as we know this, we can make concrete suggestions as to how this can be implemented with or without SAF.

[patel]

@vknow360

You will have to pick the document at least once to get access to it. After getting uri you can read from file anytime.

Ther'is a way to avoid many folders selections to find the desired file ?

[Anke]

@patel

to find the desired file

How do you / the user know what the desired file is (and where that file is located)?

[patel]

My fle path is /storage/emulated/0/MyFolder/Appunti.txt, I'm sure it exists, I would pick on it without many folders selections

[Anke]

@patel

My fle path is /storage/emulated/0/MyFolder/Appunti.txt, I'm sure it exists

Ok, since you seem to know what the file is called and where it is located, where is the problem then?