Check if folder is writeable

Question

Hi all,
I have an air app which runs fine. My only concern deals with soem folder I ask user to pick.
Some folders that I think are system protected lead my application to fail.
For example, any subfolder of the opt folder on my mac.
So I am searching without luck how to check if the selected folder is writeable or not ? Any insight ?
Thanks in advance,
Loic

Answer 1

Hello,
there is no api to test for attributes (like canRead/canWrite/isHidden/etc). You could cast your vote here:
http://ideas.adobe.com/ct/ct_a_view_idea.bix?c=9D564F43-979A-4E35-AA21-85A61B6AB8DE&idea_i d=852B26FE-E642-428B-A8F8-1A6E7284FDC5
Existing solutions:
#1
do runtime error check with try/catch or by listening to appropriate error events that can be broadcasted by given operation (move/copy or write etc). If I'm not wrong there is runtime specific error for media which is read-only.
We have to check for runtime errors as "read/write" of directory is not exactly the same if application has appropriate privileges to do I/O operation with given directory.
#2
when you try to "open" FileStream for "WRITE" on in synchronous mode (so not openAsync) it will throw immediate runtime error when application cannot open filestream for "WRITE" mode:
http://livedocs.adobe.com/flash/9.0/ActionScriptLangRefV3/flash/filesystem/FileStream.html #open()
I don't think that is recommended way to test-by-action if directory is writable - but would work anyway if you're implementing writing feature into selected directory
#3
you could asynchronously use NativeProcess to run system shell functions:
[code]
ls -lo <YOUR_PATH_HERE_QUOTED_IF_REQUIRED>
to see what are attributes of path selected by user. This data would arrive asynchronously and would require you to parse it as it arrives in format like:
rwxr-xr-x@ 3 $USER  staff  102 Jun  5 12:38 /opt
(related api for Windows is ATTRIB)
hth,
kind regards,
Peter