org.exist.xquery.functions.util
Class LockFunction

java.lang.Object
  org.exist.xquery.AbstractExpression
      org.exist.xquery.PathExpr
          org.exist.xquery.Function
              org.exist.xquery.functions.util.LockFunction

All Implemented Interfaces:

CompiledXQuery, Expression, org.xmldb.api.base.CompiledExpression

Direct Known Subclasses:

ExclusiveLockFunction, SharedLockFunction

public abstract class LockFunction
extends Function

Field Summary

Fields inherited from class org.exist.xquery.Function

BUILTIN_FUNCTION_NS

Fields inherited from interface org.exist.xquery.Expression

DOT_TEST, EXPRESSION_ID_INVALID, IGNORE_CONTEXT, IN_PREDICATE, IN_UPDATE, IN_WHERE_CLAUSE, NO_CONTEXT_ID, SINGLE_STEP_EXECUTION

Method Summary

Sequence	eval(Sequence contextSequence, Item contextItem) Evaluate the expression represented by this object.
int	getCardinality() The default cardinality is Cardinality.EXACTLY_ONE.
int	returnsType() The static return type of the expression.

Methods inherited from class org.exist.xquery.Function

analyze, createFunction, dump, getArgument, getArgumentCount, getArguments, getASTNode, getDependencies, getName, getParent, getSignature, isCalledAs, setArguments, setASTNode, setParent, setPrimaryAxis, toString

Methods inherited from class org.exist.xquery.PathExpr

accept, add, add, addPath, addPredicate, dump, getContext, getDocumentSet, getExpression, getLastExpression, getLength, getLiteralValue, getSource, isValid, replaceLastExpression, reset, resetState, setContext, setSource

Methods inherited from class org.exist.xquery.AbstractExpression

eval, getContextDocSet, getContextId, getExpressionId, setContextDocSet

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.exist.xquery.CompiledXQuery

eval

Method Detail

eval

public Sequence eval(Sequence contextSequence,
                     Item contextItem)
              throws XPathException

Description copied from interface: Expression

Evaluate the expression represented by this object. Depending on the context in which this expression is executed, either the context sequence, the context item or both of them may be set. An implementing class should know how to handle this. The general contract is as follows: if the Dependency.CONTEXT_ITEM bit is set in the bit field returned by Expression.getDependencies(), the eval method will be called once for every item in the context sequence. The contextItem parameter will be set to the current item. Otherwise, the eval method will only be called once for the whole context sequence and contextItem will be null. eXist tries to process the entire context set in one, single step whenever possible. Thus, most classes only expect context to contain a list of nodes which represents the current context of the expression. The position() function in XPath is an example for an expression, which requires both, context sequence and context item to be set. The context sequence might be a node set, a sequence of atomic values or a single node or atomic value.

Specified by:

eval in interface Expression

Specified by:

eval in class Function

Parameters:

contextSequence - the current context sequence.

contextItem - a single item, taken from context. This defines the item, the expression should work on.

Throws:

XPathException

getCardinality

public int getCardinality()

Description copied from class: AbstractExpression

The default cardinality is Cardinality.EXACTLY_ONE.

Specified by:

getCardinality in interface Expression

Overrides:

getCardinality in class Function

returnsType

public int returnsType()

Description copied from interface: Expression

The static return type of the expression. This method should return one of the type constants defined in class Type. If the return type cannot be determined statically, return Type.ITEM.

Specified by:

returnsType in interface Expression

Overrides:

returnsType in class Function