Hello,

I am trying to use XmlConfig to store simple configuration data, but I can't make it create a sensible Xml file. This is not really important in my situation, as XmlConfig is able to correctly read back the strange data it wrote, but frustrating. I searched the web but could not find any example. So can anyone offer a working example of creating a xml file with XmlConfig?

can you provide a sample of what is being created and what you are expecting to actually see?

From http://wiki.lazarus.freepascal.org/xmlconf, looks like simply setting

FileName will do.

2013/11/27 leledumbo

>From http://wiki.lazarus.freepascal.org/xmlconf, looks like simply setting FileName will do.

Yes, that part works. I dislike the way it works (Implicit saving does not seem very Pascal-ish to me), but it does save a file. My issues are rather with the xml, but I'll rather answer to waldo kitty here

TIniFile and TMemIniFile do an implicit save as well... (the former during each .Write* the latter during destruction)

Regards,
Sven
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.lazarus.freepascal.org/pipermail/lazarus/attachments/20131127/ea97a2a3/attachment-0001.html>

2013/11/27 waldo kitty

I'm trying something like (just the minimum code, but I can give the complete sources if it makes things easier):

procedure TForm1.Button1Click(Sender: TObject);
const FILE_NAME = 'pXmlConfig.xml' ;
begin
  XmlConfig1.Filename := FILE_NAME ;
//  XmlConfig1.OpenKey ('/CONFIG') ;
  XmlConfig1.SetValue ('/CONFIG/L5', 'xx') ;
  XmlConfig1.SetValue ('/L1/L2', 'aa') ;
  XmlConfig1.SetValue ('/L1/L3', 'bb') ;
  XmlConfig1.SetValue ('/L1/L2', 'cc') ;
  XmlConfig1.SetValue ('/L8', 'dd') ;
//  XmlConfig1.CloseKey ;
  XmlConfig1.Flush
end;

(No, it does not make any sense, just me trying to figure out how it works.)

And here is the result:

<?xml version="1.0" encoding="utf-8"?>
<CONFIG L8="dd">
<CONFIG L5="xx"/>
<L1 L2="cc" L3="bb"/>
</CONFIG>

The only thing which worked as I wanted is that SetValue ('/L1/L2', 'aa') is overwritten by SetValue ('/L1/L2', 'cc')

- How do I create third level keys? (or is XmlConfig able to do more than 2 levels?)
- Why does XmlConfig create L2, L3 and L5 as attributes ("/" usually is a level separator, is it not) ?
- More generally, is XmlConfig suited to do more than a simple list (which would be even less than a .ini can do)?

2013/11/27 Sven Barth

Yes. But my Pascal reference is Assign - Reset/Rewrite, Close. I still have difficulties appending "File" after Assign and Close :-P Now that I think of it, I never tried to do a new AssignFile after the Reset/Rewrite step, but I would be much surprised if it flushed and closed the first file handle. Anyhow, this is not a real problem as long as it is documented, and the effect of changing the name is documented in the wiki.

2013/11/27 Frederic Da Vitoria

Now that I am thinking of it, I may be expecting too much. If XmlConfig handles more than 2 levels, then why stop to 3? And then, how would XmlConfig be different from a full Xml Implementation?

But XmlConfig is AFAIK a spiritual "successor" to TIniFile which is why I brought it up.

Now that I think of it, I never tried to do a new AssignFile after the Reset/Rewrite step, but I would be much surprised if it flushed and closed the first file handle.

It won't flush or close the file, but if you haven't copied the Textfile or File variable somewhere else then you'll lose the reference to the file. It will be closed when the application is terminated, but everything that was not flushed until the Assign will stay in the buffer and won't be in the file... Of course this problem is a bit theoretical and is not really related to your problem :)

Regards,
Sven
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.lazarus.freepascal.org/pipermail/lazarus/attachments/20131127/7261cc79/attachment-0001.html>

The empty root '/' at the beginning is not needed.

> - How do I create third level keys? (or is XmlConfig able to do more than > 2 levels?)

cfg.SetValue('/L1/L2/L3','value');

> - Why does XmlConfig create L2, L3 and L5 as attributes ("/" usually is a > level separator, is it not) ?

TXMLConfig is a simple wrapper to store name/value pairs in xml. You can access the full XML via cfg.Doc.

> - More generally, is XmlConfig suited to do more than a simple list

You can store lists, trees, graphs as name/value pairs.

> (which would be even less than a .ini can do)?

If you only use TXMLConfig and not the Doc then it can do the same as a TIniFile. Of course there are speed and size differences.

Now that I am thinking of it, I may be expecting too much. If XmlConfig handles more than 2 levels, then why stop to 3? And then, how would XmlConfig be different from a full Xml Implementation?

TXMlConfig uses a pretty complete XML parser/writer.

Mattias

2013/11/27 Sven Barth

Ah, OK.

Absolutely :-)

2013/11/27 Mattias Gaertner

Thanks to all the advice, I managed to make it work. I will add my example to the wiki in order to make this clear to other users as ignorant as I am :-)