I'm a beginner in XML. I just studied namespaces, and I struggle a little bit so my question is in this example,
<s:root xmlns:s="help.com">
<h></h>
</s:root>
can we have <h> without the s: prefix ?
If yes, is <h> included in the s: namespace or not?
I know is a dumb questions, but every one start dumb. Thanks for your answers.
Your question is not "dumb" at all — actually reflects advanced emerging understanding.
"Should" XML questions may be answered at two levels: well-formedness and validity.
Your XML is indeed well-formed. It follows all of the rules for
being XML. It even follows all of the rules for being
namespace-well-formed. Under the rules of XML well-formedness, yes,
you can have an h element without a s: prefix. (Under the rules of
namespace-well-formedness, you can as well — you just couldn't have
a d:h element with an undeclared d namespace prefix.)
Your XML may or may not be valid. In XML terms, to be valid
implies that it follows the rules given by a schema (commonly XSD;
less commonly DTD, Relax NG, Schematron, ...). Under the rules of validity
given by an XML schema, you may or may not be able to have an h element
in that position — we would have to have an XML schema to know.
For your XML,
<s:root xmlns:s="help.com">
<h></h>
</s:root>
root is in the help.com namespace.h is in no namespace.For this XML,
<root xmlns="help.com">
<h></h>
</root>
root is in the help.com namespace.h is also in the help.com namespace because xmlns="help.com" declares
a default namespace that applies to root and all descendent elements
lacking namespace declarations.(a) Yes, your example is well-formed.
(b) The h element is in no namespace. An unprefixed element is in a namespace only if it is within the scope of a default namespace declaration (xmlns="some-url")
Your example XML is valid so, yes, h element can be withou prefix s:, and it means that h is in empty namespace, not in the same namespace as referenced by the prefix s:. Descendant elements without prefix inherit default namespace implicitly, but not with prefixed namespaces.
