org.jaxen
public interface VariableContext
Variables within an XPath expression are denoted using
notation such as $varName
or
$nsPrefix:varName
, and may
refer to a Boolean
, Double
, String
,
node-set (List
) or individual XML node.
When a variable is bound to a node-set, the
actual Java object returned should be a java.util.List
containing XML nodes from the object-model (e.g. dom4j, JDOM, DOM, etc.)
being used with the XPath.
A variable may validly be assigned the null
value,
but an unbound variable (one that this context does not know about)
should cause an {@link UnresolvableException} to be thrown.
Implementations of this interface should implement Serializable
.
See Also: SimpleVariableContext
Method Summary | |
---|---|
Object | getVariableValue(String namespaceURI, String prefix, String localName) An implementation should return the value of an XPath variable
based on the namespace URI and local name of the variable-reference
expression.
|
It must not use the prefix parameter to select a variable, because a prefix could be bound to any namespace; the prefix parameter could be used in debugging output or other generated information. The prefix may otherwise be ignored.
Parameters: namespaceURI the namespace URI to which the prefix parameter
is bound in the XPath expression. If the variable
reference expression had no prefix, the namespace
URI is null
. prefix the prefix that was used in the variable reference
expression; this value is ignored and has no effect localName the local name of the variable-reference
expression. If there is no prefix, then this is
the whole name of the variable.
Returns: the variable's value (which can be null
)
Throws: UnresolvableException when the variable cannot be resolved