iolib.lua

-- io operations

local iolib = {}

-- returns true if the file exists
local function fileExists( filename, base )
	local path = system.pathForFile( filename, base )
	local file = io.open( path, "r" )
	if file then
		io.close(file)
	    return true
	end
	return false
end
iolib.fileExists = fileExists

-- deletes a file
function removeFile( filename, base )
	local path = system.pathForFile( filename, base )
	return os.remove( path )
end
iolib.removeFile = removeFile

-- will write data to the specified application directory
function write( filename, base, data )
	local path = system.pathForFile( filename, base )
	print("Write Path:",path)
	local file = io.open( path, "w" )
	file:write( data )
	io.close( file )
	file = nil
	return nil
end
iolib.write = write

-- will read data from the specified application directory
function read( filename, base, decrypt )
	local path = system.pathForFile( filename, base )
	print("Read Path:",path)
	local file, errStr = io.open( path, "rb" )
	local data = nil
	if (file) then
		data = file:read( "*a" )
		io.close( file )
	end
	file = nil
	return data, success
end
iolib.read = read

-- reads from the read-only resource directory
function rResource( filename )
	if (data) then
		return nil
	else
		return read( filename, system.ResourceDirectory )
	end
end
iolib.rResource = rResource

-- writes and reads to/from the permanent documents directory
function wrDocs( filename, data )
	if (data) then
		return write( filename, system.DocumentsDirectory, data )
	else
		return read( filename, system.DocumentsDirectory )
	end
end
iolib.wrDocs = wrDocs

-- writes and reads to/from the short-term temporary directory
function wrTemp( filename, data )
	if (data) then
		return write( filename, system.TemporaryDirectory, data )
	else
		return read( filename, system.TemporaryDirectory )
	end
end
iolib.wrTemp = wrTemp

-- writes and reads to/from the cache directory (longer life than temp)
function wrCache( filename, data )
	if (data) then
		return write( filename, system.CachesDirectory, data )
	else
		return read( filename, system.CachesDirectory )
	end
end
iolib.wrCache = wrCache

-- save table to json file
function saveTable(fp, tbl)
	local path = system.pathForFile(fp, system.DocumentsDirectory)
	
	file = io.open(path, "w")
	file:write(json.encode(tbl))
	io.close(file)   
end
iolib.saveTable = saveTable

-- load table from json file
function readTable(fp, baseDirectory)     
	local path = system.pathForFile( fp, baseDirectory or system.DocumentsDirectory)
	
	file = io.open(path, "r")
	
	local myTable = {}  
	
	if file then
		myTable = json.decode( file:read("*a")) 
		io.close(file)
   		return myTable
	else
		return nil
	end
end
iolib.readTable = readTable

return iolib