Reading from text files, config files and similar

Monkey Forums/Monkey Code/Reading from text files, config files and similar

matty

(Posted 2011) [#1]

Here is a simple program & class I use to parse my text files, hopefully you may find it useful.

Class "TextFile"

Strict
Import mojo.app

Class TextFile

Field filecontent:String
Field currentline:String
Field remaininglines:String

Method New(filename:String)

filecontent = LoadString(filename)	' Load text file into string
remaininglines = filecontent.Replace("~n","") 'Remove newline characters

End

Method Eof:Bool() 'check for End-of-file - returns true if end of file reached

If remaininglines = ""
	Return True
Else
	Return False
Endif

End 

Method GetLine:String()

Return currentline	'return the current line in the text file

End 

Method ReadLine:Void()	'read the next line in the file into the currentline
Local newlinecharindex:Int

If Eof()

Else

	newlinecharindex = remaininglines.Find("~r") 'look for carriage returns and return the text that is before that..
	currentline = remaininglines[0..newlinecharindex]
	remaininglines = remaininglines[newlinecharindex+1..]
	
Endif 

End 

Method GetDataName:String() 
' see example for details on how this is used, basically returns text in the current line before the equals sign, useful for config files and the like

Local equalsposition:Int
equalsposition = currentline.Find("=")

If equalsposition = -1 Then Return "" Else Return currentline[0..equalsposition]


End 


Method GetDataValue:String()
' see example for details on how this is used, basically returns text in the line after the equals sign..useful for config files and the like

Local equalsposition:Int
equalsposition = currentline.Find("=")


If equalsposition = -1 Then Return "" Else Return currentline[equalsposition+1..]

End


End Class

Example

Strict

Import mojo
Import textfile

Function Main:Int()

Local app:MyApp
app = New MyApp

Return 0
End Function 

Class MyApp Extends App

Method OnCreate:Int()

Local file:TextFile
file = New TextFile("test.txt")
If file <> Null Then
	While file.Eof()=False
		file.ReadLine()
		Print file.GetLine()
		Print file.GetDataName()
		Print file.GetDataValue()
	End While
Endif 

End Method

End Class

Sample test file which needs to be saved as "test.txt" in .data folder

this is a String in a text file
x=1
y=123
colour=red
name=Matt
programming=fun

c.k.	(Posted 2011) [#2]

In the text file, you could store it as

x=#1 ' this will give you a float
y=%123.3 ' this will give you an integer
colour=red ' this is automatically a string
z="75040" ' this is a string
a=75040 'this is a string

So even though the file is all text, when you load it, you get the original values of your variables.

I'd be surprised if something like this wasn't already available actually.

matty

(Posted 2011) [#3]

I was surprised too that I couldn't find anything like this anywhere for monkey already! (which is why I made my own - but I'm happy to be pointed to an existing solution for Monkey).

Earok

(Posted 2011) [#4]

Just a quick query - why not use split?

Local lines:String[] = LoadString(fileName).Split("~n")

For Local line:String = Eachin lines
     Local values:String[] = line.Split("=")
     print "Key:" + values[0]
     print "Value:" + values[1]
Next

xzess

(Posted 2011) [#5]

Hey thanks pretty nice solution.

I made this from your ideas

Class FileIO
	Field FileContent:String
	Field lines:String[]

	
	Method SaveValue(Key:String,Value:String)
	FileContent += (Key+"="+Value + "~n")
	End
	
	Method GetValue:String(Key:String)
		 lines = LoadState.Split("~n")
		
		For Local line:String = Eachin lines
		     Local values:String[] = line.Split("=")
		     
			 If(values[0] = Key)
			 Return values[1]
			 End
		Next
		
		
	End
	
	Method SaveAll()
	SaveState(FileContent)
	End
End

Save some vars:

Field File:FileIO

Method OnCreate()
 File = New FileIO
 File.Save("Test","Apple")
 File.Save("Test2","Pie")
 File.SaveAll()
End

Load those vars:

Field File:FileIO
Field Str:String
Method OnCreate()
 File = New FileIO
 Str = File.GetValue("Test2")
End

Skn3	(Posted 2011) [#6]

In the config examples that comes with monkey there is an XML parser if that is any help. There is also an updated version here: http://www.monkeycoder.co.nz/Community/post.php?topic=326&post=2369

xzess

(Posted 2011) [#7]

Thanks man!

Samah

(Posted 2011) [#8]

Diddy also has its own XML parser if you were interested.

c.k.	(Posted 2012) [#9]

OK, I'm using a FileIO module (who did this?), and want to add a "DeleteKeyPair()" method... Can anybody lend a hand? Thank you! :-)

Import mojo

Class FileIO
	Field FileContent:String
	Field lines:String[]

	Method DeleteKeyPair( Key:String )
		' HOW TO DO THIS PART?!
		' remove a key and its value from FileContent
		' if it doesn't exist, no worries
	End
	
	Method SaveValue(Key:String,Value:String)
		DeleteKeyPair( Key )			' remove any prior key+value pair first
		FileContent += (Key+"="+Value + "~n")	' add this new key+value pair
	End
	
	Method GetValue:String(Key:String)
		lines = LoadState.Split("~n")
		For Local line:String = Eachin lines
		     Local values:String[] = line.Split("=")
			 If(values[0] = Key)
				 Return values[1]
			 End
		Next
		Return ""
	End

	Method GetValue:String(Key:Int)
		lines = LoadState.Split("~n")
		For Local line:Int = 0 to lines.Length - 1
			Print lines[line]
		Next
		Return lines[Key]
	End
	
	Method GetAll:String[]()
		Return LoadState.Split("~n")
	End

	Method GetRaw:String()
		Return LoadState()
	End
	
	Method SaveAll()
		SaveState(FileContent)
	End
	
	Method Destroy()
		SaveState("")
	End
	
End

c.k.	(Posted 2012) [#10]

I wrote it. Here it is. Any improvements welcome.

[monkeycode]
Method DeleteValue( Key:String )
Local newFC:String = ""
' remove a key and its value from FileContent
' if it doesn't exist, no worries
lines = GetAll()
If lines.Length() > 0 Then
For Local line:String = Eachin lines
Local values:String[] = line.Split("=")
If values.Length() > 1 Then
If (values[0]<>Key) Then
newFC += (values[0]+"="+values[1]+"~n")
EndIf
Endif
Next
Endif
FileContent = newFC
SaveAll()
End
[/monkeycode]

muddy_shoes

(Posted 2012) [#11]

If you intend to use this a lot then you should probably think about the performance issues. As stands you're parsing the data and doing a linear search on every fetch and parsing, searching and then rebuilding it all again on every write/delete (although curiously the code saves after the delete but not after writing an new value).

c.k.	(Posted 2012) [#12]

It doesn't happen a lot, and certainly not enough to worry about performance (I think). Here's the full thing I'm using, and it looks like AddValue() does save after the write.

[monkeycode]
Import mojo

Class FileIO
Field FileContent:String
Field lines:String[]

Method OnCreate:VOID()
FileContent = GetAll()
End

Method DeleteValue( Key:String )
Local newFC:String = ""
' remove a key and its value from FileContent
' if it doesn't exist, no worries
lines = GetAll()
If lines.Length() > 0 Then
For Local line:String = Eachin lines
Local values:String[] = line.Split("=")
If values.Length() > 1 Then
If (values[0]<>Key) Then
newFC += (values[0]+"="+values[1]+"~n")
EndIf
Endif
Next
Endif
FileContent = newFC
SaveAll()
End

Method AddValue(Key:String,Value:String)
DeleteValue( Key ) ' remove any prior key+value pair
FileContent += (Key+"="+Value + "~n") ' add this new key+value pair
SaveAll()
End

Method GetValue:String(Key:String)
'lines = LoadState.Split("~n")
lines = GetAll()
For Local line:String = Eachin lines
Local values:String[] = line.Split("=")
If(values[0] = Key)
Return values[1]
End
Next
Return ""
End

Method GetAll:String[]()
Return LoadState.Split("~n")
End

Method GetRaw:String()
Return LoadState()
End

Method SaveAll()
SaveState(FileContent)
End

Method Destroy()
SaveState("")
End

End
[/monkeycode]

Any hints, tips, tricks are welcome. Thanks!

muddy_shoes

(Posted 2012) [#13]

Yes, well that's different code to what you posted above. Now you're saving twice when setting a value, once when deleting the old value and then again after adding the new one.

It may not be an issue with how you're using it now, but you should be aware that it will definitely be an issue if you use it for any non-trivial amounts of data, especially on a platform such as Android.