Mandating xsi type attribute in a xml schema Chat sxe
Although there were some differences in unbinding prefixed namespaces, both versions allow you to unbind or remove the already declared by overriding it with another declaration, where the namespace in the overriding declaration is empty.
Unbinding a namespace is as good as the namespace not being declared at all.
One of the primary motivations for defining an XML namespace is to avoid naming conflicts when using and re-using multiple vocabularies.
XML Schema is used to create a vocabulary for an XML instance, and uses namespaces heavily.
Just as shelves partition the entire space in a refrigerator, the symbol spaces partition the namespace.
There are three primary partitions in a namespace: one for global element declarations, one for global attribute declarations, and one for global type declarations (complex Type/simple Type).
A is declared as follows: Unbinding an already-bound prefix is not allowed per the W3C Namespaces in XML 1.0 Recommendation, but is allowed per W3C Namespaces in XML 1.1 Recommendation.
Note that the prefixes are used only as a placeholder and must be expanded by the namespace-aware XML parser to use the actual namespace bound to the prefix.
In Java analogy, a namespace binding can be correlated to declaring a variable, and wherever the variable is referenced, it is replaced by the value it was assigned.
By now it should be clear that to use a namespace, we first bind it with a prefix and then use that prefix wherever required.
But why can't we use the namespaces to qualify the elements or attributes from the start?