org.exist.xquery
Class UserDefinedFunction

java.lang.Object
  org.exist.xquery.AbstractExpression
      org.exist.xquery.PathExpr
          org.exist.xquery.Function
              org.exist.xquery.UserDefinedFunction

All Implemented Interfaces:

java.lang.Cloneable, CompiledXQuery, Expression, RewritableExpression, org.xmldb.api.base.CompiledExpression

public class UserDefinedFunction
extends Function
implements java.lang.Cloneable

Field Summary

Fields inherited from class org.exist.xquery.Function

BUILTIN_FUNCTION_NS, mySignature

Fields inherited from class org.exist.xquery.PathExpr

inPredicate, keepVirtual, LOG, staticContext, steps

Fields inherited from class org.exist.xquery.AbstractExpression

column, context, contextDocSet, contextId, line, unordered

Fields inherited from interface org.exist.xquery.Expression

DOT_TEST, EXPRESSION_ID_INVALID, IGNORE_CONTEXT, IN_NODE_CONSTRUCTOR, IN_PREDICATE, IN_UPDATE, IN_WHERE_CLAUSE, NEED_INDEX_INFO, NO_CONTEXT_ID, NON_STREAMABLE, POSITIONAL_PREDICATE, SINGLE_STEP_EXECUTION, UNORDERED, USE_TREE_TRAVERSAL

Constructor Summary

UserDefinedFunction(XQueryContext context, FunctionSignature signature)

Method Summary

void	accept(ExpressionVisitor visitor) Start traversing the expression tree using the specified ExpressionVisitor.
void	addVariable(java.lang.String varName)
void	analyze(AnalyzeContextInfo contextInfo) Statically analyze the expression and its subexpressions.
java.lang.Object	clone()
void	dump(ExpressionDumper dumper) Write a diagnostic dump of the expression to the passed ExpressionDumper.
Sequence	eval(Sequence contextSequence, Item contextItem) Evaluate the expression represented by this object.
FunctionCall	getCaller()
protected Sequence[]	getCurrentArguments()
int	getDependencies() Returns Dependency.DEFAULT_DEPENDENCIES.
Expression	getFunctionBody()
java.util.List<QName>	getParameters() Return the functions parameters list
boolean	needsReset() Returns true if the expression object has not yet been reset, so Expression.resetState(boolean) should be called.
void	resetState(boolean postOptimization) Called to inform an expression that it should reset to its initial state.
void	setArguments(Sequence[] args, DocumentSet[] contextDocs)
void	setCaller(FunctionCall call)
void	setFunctionBody(Expression body)
java.lang.String	toString()

Methods inherited from class org.exist.xquery.Function

checkArgument, checkArguments, createFunction, getArgument, getArgumentCount, getArguments, getCardinality, getName, getParent, getParentModule, getSignature, isCalledAs, returnsType, setArguments, setParent, setPrimaryAxis, simplify

Methods inherited from class org.exist.xquery.PathExpr

add, add, addPath, addPredicate, allowMixNodesInReturn, dump, getColumn, getContext, getDocumentSet, getExpression, getLastExpression, getLength, getLine, getLiteralValue, getPrimaryAxis, getSubExpression, getSubExpressionCount, isValid, replaceExpression, replaceLastExpression, reset, setContext, setUseStaticContext

Methods inherited from class org.exist.xquery.AbstractExpression

eval, getContextDocSet, getContextId, getExpressionId, getSource, match, setASTNode, setContextDocSet, setContextId, setLocation

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.exist.xquery.CompiledXQuery

eval, getSource

Constructor Detail

UserDefinedFunction

public UserDefinedFunction(XQueryContext context,
                           FunctionSignature signature)

Method Detail

setFunctionBody

public void setFunctionBody(Expression body)

getFunctionBody

public Expression getFunctionBody()

addVariable

public void addVariable(java.lang.String varName)
                 throws XPathException

Throws:

XPathException

setArguments

public void setArguments(Sequence[] args,
                         DocumentSet[] contextDocs)
                  throws XPathException

Throws:

XPathException

analyze

public void analyze(AnalyzeContextInfo contextInfo)
             throws XPathException

Description copied from interface: Expression

Statically analyze the expression and its subexpressions. During the static analysis phase, the query engine can detect unknown variables and some type errors.

Specified by:

analyze in interface Expression

Overrides:

analyze in class Function

Throws:

XPathException

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

dump

public void dump(ExpressionDumper dumper)

Description copied from interface: Expression

Write a diagnostic dump of the expression to the passed ExpressionDumper.

Specified by:

dump in interface Expression

Overrides:

dump in class Function

Parameters:

dumper - the expression dumper to write to

toString

public java.lang.String toString()

Overrides:

toString in class Function

getDependencies

public int getDependencies()

Description copied from class: AbstractExpression

Returns Dependency.DEFAULT_DEPENDENCIES.

Specified by:

getDependencies in interface Expression

Overrides:

getDependencies in class Function

Returns:

set of bit-flags

See Also:

Expression.getDependencies()

resetState

public void resetState(boolean postOptimization)

Description copied from interface: Expression

Called to inform an expression that it should reset to its initial state. All cached data in the expression object should be dropped. For example, the xmldb:document() function calls this method whenever the input document set has changed.

Specified by:

resetState in interface Expression

Overrides:

resetState in class PathExpr

needsReset

public boolean needsReset()

Description copied from interface: Expression

Returns true if the expression object has not yet been reset, so Expression.resetState(boolean) should be called.

Specified by:

needsReset in interface Expression

Overrides:

needsReset in class AbstractExpression

Returns:

accept

public void accept(ExpressionVisitor visitor)

Description copied from interface: Expression

Start traversing the expression tree using the specified ExpressionVisitor.

Specified by:

accept in interface Expression

Overrides:

accept in class Function

getParameters

public java.util.List<QName> getParameters()

Return the functions parameters list

Returns:

List of function parameters

clone

public java.lang.Object clone()

Overrides:

clone in class java.lang.Object

getCaller

public FunctionCall getCaller()

setCaller

public void setCaller(FunctionCall call)

getCurrentArguments

protected Sequence[] getCurrentArguments()