Click here to Skip to main content
15,887,027 members
Articles / Desktop Programming / MFC
Article

Save Application Settings to XML

Rate me:
Please Sign up or sign in to vote.
3.92/5 (5 votes)
16 Sep 20022 min read 259.2K   1.8K   54   77
An easy to use class that reads, writes and deletes app settings to an XML file.

Introduction

Why another application settings XML class?

  1. Because INI files are so Win16.
  2. The registry is too big and you could really screw something up messing with it.
  3. XML seems to be the popular choice.

See Read and Write application parameters in XML for better reasons.

This class should make it easy to read, write and delete application settings to an XML file using the familiar registry key/value nomenclature (ex. "MyApp\Appearance\Font\Face"). If it doesn't make it easy, um... I didn't write it.

The CXMLSettings Class

To use the class, there are only 6 methods you will need to worry about.

  • void SetSettingsFile(CString cstrFile)
    • Sets the path and filename for the XML settings file.
  • long GetSettingLong(CString cstrBaseKeyName, CString cstrValueName, 
    long lDefaultValue)
    • Returns a long value extracted from the settings file given a key and value name.
  • long SetSettingLong(CString cstrBaseKeyName, CString cstrValueName, 
    long lValue)
    • Sets a long value in the settings file given a key and value name.
  • CString GetSettingString(CString cstrBaseKeyName, CString 
    cstrValueName, CString cstrDefaultValue)
    • Returns a string value extracted from the settings file given a key and value name.
  • long SetSettingString(CString cstrBaseKeyName, CString cstrValueName, 
    CString cstrValue)
    • Sets a string value in the settings file given a key and value name.
  • BOOL DeleteSetting(CString cstrBaseKeyName, CString 
    cstrValueName)
    • Deletes a key or value from the settings file given a key and value name.

Other methods in the class parse key/value "chains", and load, save, and traverse the settings file.

How to Use It

  1. Call SetSettingsFile to tell the class where the XML file will be saved.
  2. Call one of the Get, Set or Delete methods using the registry-like nomenclature for the first parameter (ex. "MyApp\Appearance\Font"). A default value may also be sent as the last parameter to the Get methods.
  3. The DeleteSetting method can be used to delete an entire key or a value under a key.

That's it!

If the XML file does not exist or if a key/value does not exist, the Set methods will create it and the Get methods will return the default value.

Conclusion

The class and the demo app use MFC and MSXML 4.0. Please let me know if you find any bugs are would like to see improvements.

Other articles lie this one:

License

This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

A list of licenses authors might use can be found here


Written By
Software Developer (Senior)
United States United States
I have been a professional developer since 1996. I live in Illinois, in the USA. I am married and have four children.

Comments and Discussions

 
GeneralRe: XML vs. Registry Pin
dandy7217-Sep-02 3:59
dandy7217-Sep-02 3:59 
GeneralRe: XML vs. Registry Pin
Jason Henderson17-Sep-02 4:07
Jason Henderson17-Sep-02 4:07 
GeneralRe: XML vs. Registry Pin
Tim Smith16-Sep-02 4:02
Tim Smith16-Sep-02 4:02 
GeneralRe: XML vs. Registry Pin
Jason Henderson16-Sep-02 4:06
Jason Henderson16-Sep-02 4:06 
GeneralRe: XML vs. Registry Pin
Paul A. Howes16-Sep-02 6:57
Paul A. Howes16-Sep-02 6:57 
GeneralRe: XML vs. Registry Pin
Jason Henderson16-Sep-02 8:38
Jason Henderson16-Sep-02 8:38 
GeneralRe: XML vs. Registry Pin
Anonymous16-Sep-02 9:56
Anonymous16-Sep-02 9:56 
GeneralRe: XML vs. Registry Pin
Houdini17-Sep-02 5:16
Houdini17-Sep-02 5:16 
The first, and biggest for me, reason to use XML over the registry: portability. You may not care about writing applications for more than just Windows, but there are a ton of us out there who do. So keeping application settings in the registry just means more work later when you port your application.

A second reason is the fact that it makes it much easier to make changes to settings while in development. Nothing is worse than having to open RegEdit and find your buried application folder just to make a quick change.

Thirdly, when I delete an application I like to delete everything, this includes application settings. It's funny how my registry ballons after installing numerous applications, yet it hardly shrinks after uninstalling those applications. Of course, if I go through the registry and finally find the folder the applications are using, lo and behold, their information is still there. Much easier to just open up the application directory and delete all files located there.

Fourth, considering the registry contains information required for Windows to run, having numerous applications writing/reading from it all day long just increases the chance of corrupting the files the registry resides in.

Fifth, for those of us running a duel boot system, it sucks having to install the same application into the same directory for both operating systems, just to get the application settings written into the registry for both OS's. Yes, you could search the registry for the application in question, export the settings, then import them into the other OS's registry, but that's hardly something a common user can, or even should do. Of course, had they used files (such as XML) no extra steps would be required.

Sixth, as a few others mentioned, if users are having problems and you want to take a look at their application settings it's easier, and safer, to have them email you a file rather than trying to wade through the registry.


- Houdini
GeneralRe: XML vs. Registry Pin
Paul A. Howes17-Sep-02 6:43
Paul A. Howes17-Sep-02 6:43 
GeneralRe: XML vs. Registry Pin
Houdini17-Sep-02 7:39
Houdini17-Sep-02 7:39 
GeneralWhy XML Pin
Member 91815-Sep-02 14:06
Member 91815-Sep-02 14:06 
GeneralRe: Why XML Pin
Maximilien15-Sep-02 14:17
Maximilien15-Sep-02 14:17 
GeneralRe: Why XML Pin
Tim Kosse15-Sep-02 20:41
Tim Kosse15-Sep-02 20:41 
GeneralRe: Why XML Pin
mstephens15-Sep-02 23:31
mstephens15-Sep-02 23:31 
GeneralRe: Why XML Pin
Jiminy15-Sep-02 17:12
Jiminy15-Sep-02 17:12 

General General    News News    Suggestion Suggestion    Question Question    Bug Bug    Answer Answer    Joke Joke    Praise Praise    Rant Rant    Admin Admin   

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.