Re: A standard package for config files is needed

["SteveD" <nospam_steved94@attbi.com>]

"Preben Randhol" <randhol+abuse@pvv.org> wrote in message
news:slrnaf9djb.u9.randhol+abuse@kiuk0156.chembio.ntnu.no...
> On Wed, 29 May 2002 02:18:28 GMT, SteveD wrote:
>
> > Gee. I thought this was just the kind of thing that XMLAda was good
> > for.
> >
> > A few lines of code to read the configuration file (XML) followed by a
> > few lines of code to access the data.
> >
> > Then if you decide you want to do something more fancy with
> > configuration there is little additional cost.
>
> The problems with XML is:
>
>    1) Hard to handedit/read for the user

Here is a simple XML file, hard to edit... maybe:

<config
left="30"
right="50"
up="20"
down="60"
/>

Here is the bloated code it takes to read the values (tested):
WITH Tree_Readers; USE Tree_Readers;
WITH Ada.Text_Io;

procedure Config_Demo is

    inFile      : Input_Sources.File.File_Input;
    tree_reader : Tree_Readers.Tree_Reader;
    doc         : DOM.Core.Document;
    element     : DOM.Core.Element;
    left  : Integer;
    right : Integer;
    up    : Integer;
    down  : Integer;

begin
  Input_Sources.File.Open( "config.txt", inFile );
  Set_Feature( tree_reader, Validation_Feature, FALSE);
  Parse( tree_reader, inFile );
  doc := Get_Tree( tree_reader );
  Input_Sources.File.Close( InFile );
  element := Dom.Core.Documents.Get_Element( Doc );
  left := Integer'Value( Dom.Core.Elements.Get_Attribute( element,
"left" ) );
  right := Integer'Value( Dom.Core.Elements.Get_Attribute( element,
"right" ) );
  up := Integer'Value( Dom.Core.Elements.Get_Attribute( element, "up" ) );
  down := Integer'Value( Dom.Core.Elements.Get_Attribute( element,
"down" ) );
  Ada.Text_Io.Put_Line( "Left: " & Integer'IMAGE( left ) );
  Ada.Text_Io.Put_Line( "Right: " & Integer'IMAGE( right ) );
  Ada.Text_Io.Put_Line( "Up: " & Integer'IMAGE( up ) );
  Ada.Text_Io.Put_Line( "DOwn: " & Integer'IMAGE( down ) );
end Config_Demo;

If all you want is value attribute pairs, it would certainly be easy to put
this inside a wrapper package.


>    2) Have applications depend on XML/Ada for only the config files
>       seams bloat.

Perhaps.  But re-inventing the wheel seems a crying shame.

>    3) Would need a DTD for each the config file

XML does not require a DTD.  You may give one if you want, but they are
definitely not required.

>
> Preben