Android Filing System using LC9

[Peter Reid]

I've investigated further the way the Android filing system seems to be available to LC 9.0.0-dp10. As I reported previously, I have found several anomalies.

Here's what I've found, (with my app being identified as "com.reidit.aphtrain" in the examples):

1. The internal storage area pointed to by specialFolderPath("engine") or specialFolderPath("resources") is Read-Only (RO) and contains any files & folder specified in Standalone settings to be included in the Copy Files section.  Specifically, the path returned by "engine"/"resources" is:

	/data/app/com.reidit.aphtrain-2/base.apk

This can be accessed RO reliably and seems to be the correct behaviour.

2. The internal storage area pointed to by specialFolderPath("documents") is Read-Write (RW) and can be used as such. However, the path returned by "documents" is INCORRECT:

	/data/data/com.reidit.aphtrain/files

The correct path should be:

	/Android/data/com.reidit.aphtrain/files

If I replace the leading "data" with "Android", the path works fully with RW access.

3. If I pre-load files & folders onto a microSD card on my computer, I have to place them in a path such as:

	/Android/com.reidit.aphtrain/<files & folders>

Such files & folders are Read-Only in the tablet and accessible using the following path:

	/storage/sdcard1/Android/com.reidit.aphtrain/<files & folders>

It seems that Android 5 or later (FireOS 5 in my case) locks down SD cards. They used to be fully RW but are now treated as mainly RO apart from an area for the app to use. If I get the path from specialFolderPath("external documents"), the path gives me Read-Write access to the following area:

	/storage/emulated/0/Android/data/com.reidit.aphtrain/files/<files & folders>

During the running of the app, the above path works fully for RW access but doesn't show any of the pre-loaded files & folders.  However, If I connect the microSD card to my computer again, this area is NOT VISIBLE!

In summary, we seem to have the following available in LC 9:

WHERE		SPECIAL		ACCESS	TABLET?	MAC?	PATH
1. internal	"engine"	RO	Yes	No	/data/app/com.reidit.aphtrain-2/base.apk

2. internal	"documents"	RW	ERROR	No	/data/data/com.reidit.aphtrain/files

3. internal	"documents"*	RW	Yes	No	/Android/data/com.reidit.aphtrain/files

4. external	"external doc"	RW	Yes	NO	/storage/emulated/0/Android/data/com.reidit.aphtrain/files

5. external	"external doc"*	RO	Yes	Yes	/storage/sdcard1/Android/com.reidit.aphtrain

The result of the above is that it is difficult creating files & folders on the fly that you can get out of the tablet afterwards such that they can be read on a computer!

Can anyone confirm my findings and make recommendations?

Also, specialFolderPath("documents") seems to have a BUG as it delivers the wrong path (in LC 9.0.0-dp9/10).

Thanks

Peter