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 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