system.pathForFile Returning Nil

[ddubya82]

Hi all,

I’ve read up on system.pathForFile on Android devices, but still have a question.

I’m storing a .RAD file (Radiance Particle Engine) in {root}/custom/particles folder.  Everything works fine in Simulator but system.pathForFile is returning nil on Android.

The code defining path is simple enough (dir = relative path, fx = filename):

function create(fx,dir) if dir==nil then path=system.pathForFile(fx) else path=system.pathForFile(dir.."\\"..fx) end .....

However, on Android device this will only work if I do NOT specify “dir” and store the .RAD files in the root of the project, which I really do not want to do.

I understand that the system.ResourcesDirectory constant is the default in system.pathForFile , which according to Documentation will return nil.  But as I said, if I don’t specify “dir”, this all works on my Android device!

My call to the method defining the path is like this:

create("file.rad", "custom/particles")

Any help would be appreciated.

Cheers.

[roaminggamer]

Hi again.  Actually what was the question? 

UPDATE: Deleted my prior posts till I’m clear on question.

I read that again and it seems like you know it shouldn’t work and I just don’t quite get the question.  In fact, there is no question in the post.  :unsure:

A better format for a post is:

1. What I did.  - This is essentially you telling us what you want to do.

2. What I saw.

3. What I expected to see and why I expected to see it. - This is where you are telling us why you think #2 is wrong.

4. What I did to debug the issue.

5. What can I do to get what I expected in #3?

[roaminggamer]

Having not gotten that question  yet, “I am assuming you are having issues reading files on Android from sub-folders.”

Here is a test showing how to do it:

https://github.com/roaminggamer/RG_FreeStuff/raw/master/AskEd/2018/04/androidResourceDirectory.zip

local function readFile( fileName ) local path = system.pathForFile( fileName, system.ResourceDirectory ) local f = io.open( path,"rb") if (f == nil) then print( "Failed to open", fileName ) return nil end fileContents = f:read( "\*a" ) io.close(f) return fileContents end local files = { "test1.txt", "test1.rad", "data/test1.txt", "data/test1.rad" } for i = 1, #files do print("Trying to read: ", files[i] ) local data = readFile( files[i] ) print( "Got:\n", data, "\n-----------------\n" ) end

Here is the output from logcat on my Android device:

I/Corona (21455): Trying to read: test1.txt I/Corona (21455): Got: I/Corona (21455): 1 I/Corona (21455): 2 I/Corona (21455): 3 I/Corona (21455): 4 I/Corona (21455): 5 I/Corona (21455): ----------------- I/Corona (21455): Trying to read: test1.rad I/Corona (21455): Got: I/Corona (21455): 1 I/Corona (21455): 2 I/Corona (21455): 3 I/Corona (21455): 4 I/Corona (21455): 5 I/Corona (21455): ----------------- I/Corona (21455): Trying to read: data/test1.txt I/Corona (21455): Got: I/Corona (21455): 1 I/Corona (21455): 2 I/Corona (21455): 3 I/Corona (21455): 4 I/Corona (21455): 5 I/Corona (21455): ----------------- I/Corona (21455): Trying to read: data/test1.rad I/Corona (21455): Got: I/Corona (21455): 1 I/Corona (21455): 2 I/Corona (21455): 3 I/Corona (21455): 4 I/Corona (21455): 5 I/Corona (21455): -----------------

[roaminggamer]

That weird indent for first line is from print() adding a tab between args, not a error in the read.

[davebollinger]

pathForFile only works for pre-packaged files in the resource directory. ie, you can’t use it to create new files in the resource directory, you’ll need to create those elsewhere (fe documents directory)

[ddubya82]

Hey guys, sorry for the ambiguous (or completely absent) question…  The basis of my question was, “why this no work on device, but work in Simulator?”  

@roaming, luckily your deleted responses were also emailed to me as one of those contained the answer.  :)  The specific problem was caused by the back-slash when appending directory and filename.   New code is as follows:

if dir==nil then path=system.pathForFile(fx) else path=system.pathForFile(dir.."/"..fx) end

My other point of confusion was due to misreading of Corona Documentation.  I thought the docs were saying that system.ResourceDirectory was default, but would also perpetually return nil on Android.

Thanks for the help.  I’ll try to be more clear in future!

Cheers.

 

[roaminggamer]

You simply can’t write to the resource directory/folder on devices (iOS or Android). 

This is a well documented and established rule.  The sandboxing and other permission rules for devices are very strict.

You can in Windows and OS X, but that is because:

1. It is an actual folder.
2. You have permission to do so.

Neither of those is true for Android.

[ddubya82]

Understood.  My issue dealt solely with reading a file that is present in the game files.

[roaminggamer]

Hi again.  Actually what was the question? 

UPDATE: Deleted my prior posts till I’m clear on question.

I read that again and it seems like you know it shouldn’t work and I just don’t quite get the question.  In fact, there is no question in the post.  :unsure:

A better format for a post is:

1. What I did.  - This is essentially you telling us what you want to do.

2. What I saw.

3. What I expected to see and why I expected to see it. - This is where you are telling us why you think #2 is wrong.

4. What I did to debug the issue.

5. What can I do to get what I expected in #3?

[roaminggamer]

Having not gotten that question  yet, “I am assuming you are having issues reading files on Android from sub-folders.”

Here is a test showing how to do it:

https://github.com/roaminggamer/RG_FreeStuff/raw/master/AskEd/2018/04/androidResourceDirectory.zip

local function readFile( fileName ) local path = system.pathForFile( fileName, system.ResourceDirectory ) local f = io.open( path,"rb") if (f == nil) then print( "Failed to open", fileName ) return nil end fileContents = f:read( "\*a" ) io.close(f) return fileContents end local files = { "test1.txt", "test1.rad", "data/test1.txt", "data/test1.rad" } for i = 1, #files do print("Trying to read: ", files[i] ) local data = readFile( files[i] ) print( "Got:\n", data, "\n-----------------\n" ) end

Here is the output from logcat on my Android device:

I/Corona (21455): Trying to read: test1.txt I/Corona (21455): Got: I/Corona (21455): 1 I/Corona (21455): 2 I/Corona (21455): 3 I/Corona (21455): 4 I/Corona (21455): 5 I/Corona (21455): ----------------- I/Corona (21455): Trying to read: test1.rad I/Corona (21455): Got: I/Corona (21455): 1 I/Corona (21455): 2 I/Corona (21455): 3 I/Corona (21455): 4 I/Corona (21455): 5 I/Corona (21455): ----------------- I/Corona (21455): Trying to read: data/test1.txt I/Corona (21455): Got: I/Corona (21455): 1 I/Corona (21455): 2 I/Corona (21455): 3 I/Corona (21455): 4 I/Corona (21455): 5 I/Corona (21455): ----------------- I/Corona (21455): Trying to read: data/test1.rad I/Corona (21455): Got: I/Corona (21455): 1 I/Corona (21455): 2 I/Corona (21455): 3 I/Corona (21455): 4 I/Corona (21455): 5 I/Corona (21455): -----------------

[roaminggamer]

That weird indent for first line is from print() adding a tab between args, not a error in the read.

[davebollinger]

pathForFile only works for pre-packaged files in the resource directory. ie, you can’t use it to create new files in the resource directory, you’ll need to create those elsewhere (fe documents directory)

[ddubya82]

Hey guys, sorry for the ambiguous (or completely absent) question…  The basis of my question was, “why this no work on device, but work in Simulator?”  

@roaming, luckily your deleted responses were also emailed to me as one of those contained the answer.  :)  The specific problem was caused by the back-slash when appending directory and filename.   New code is as follows:

if dir==nil then path=system.pathForFile(fx) else path=system.pathForFile(dir.."/"..fx) end

My other point of confusion was due to misreading of Corona Documentation.  I thought the docs were saying that system.ResourceDirectory was default, but would also perpetually return nil on Android.

Thanks for the help.  I’ll try to be more clear in future!

Cheers.

 

[roaminggamer]

You simply can’t write to the resource directory/folder on devices (iOS or Android). 

This is a well documented and established rule.  The sandboxing and other permission rules for devices are very strict.

You can in Windows and OS X, but that is because:

1. It is an actual folder.
2. You have permission to do so.

Neither of those is true for Android.

[ddubya82]

Understood.  My issue dealt solely with reading a file that is present in the game files.