[Lazarus] How is XMLConfig supposed to work?

[Frederic Da Vitoria]

2013/11/27 Mattias Gaertner <nc-gaertnma at netcologne.de>

> On Wed, 27 Nov 2013 16:54:45 +0100
> Frederic Da Vitoria <davitofrg at gmail.com> wrote:
>
> > 2013/11/27 Frederic Da Vitoria <davitofrg at gmail.com>
> >
> > > 2013/11/27 waldo kitty <wkitty42 at windstream.net>
> > >
> > >> On 11/27/2013 6:50 AM, Frederic Da Vitoria wrote:
> > >>
> > >>> 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?
> > >>
> > >
> > > 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')
>
> 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.
>

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
:-)

-- 
Frederic Da Vitoria
(davitof)

Membre de l'April - « promouvoir et défendre le logiciel libre » -
http://www.april.org
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