[jdom-interest] More changes

[Patrick Dowler]

On Wed, 19 Jul 2000, you wrote:
> > > On a somewhat related note, I'm really starting to like the idea of
> > > getChildContent(String childName) and getChildContent(String childName,
> > > String fallback).  These methods would greatly simplify my coding when
> > > reading config files.
snip
> Not any better imho.  Now let's try my proposal:
> 
> Element ip = servlet.getChild("init-param");
> String name = value = desc = null;
> if (ip != null) {
>   name = ip.getChildContent("param-name"); // may return null
>   value = ip.getChildContent("param-value");
>   desc = ip.getChildContent("description", "No description");
> }
> if (name != null && value != null) {
>   // Handle good input here
> }
> else {
>   // Handle missing elements
> }

The same thing can be accomplished with a single method in your
code or a utility class without burdening Element:

public String ensureContent( Element e, String default )
{
	if ( e == null )
		return default;
	return e.getContent();
}

Then the above example becomes:

Element ip = servlet.getChild("init-param");
String name = value = desc = null;
if (ip != null) {
  name = ensureContent( ip.getContent("param-name"), null );
  value = ensureContent( ip.getContent("param-value"), null );
  desc = ensureContent( ip.getContent("description") , "No description");
}
if (name != null && value != null) {
  // Handle good input here
}
else {
  // Handle missing elements
}

Having the code in the ensureContent (bad name) method as part of the 
above code is what makes the current situation nasty, but it can be put 
elsewhere:  add it to Element, in the form of getChildContent() or add it
to a utility class. The latter has the advantage that the same thing could be
done with getXXXContent() methods that might return a default value for
people who don't care about syntax errors.

IMO these utility methods can be easily done in a utility class and keep the
Element API lean.

--

Patrick Dowler
Canadian Astronomy Data Centre