org.exist.xquery
Class UserDefinedFunction

java.lang.Object
  extended by org.exist.xquery.AbstractExpression
      extended by org.exist.xquery.PathExpr
          extended by org.exist.xquery.Function
              extended by org.exist.xquery.UserDefinedFunction
All Implemented Interfaces:
CompiledXQuery, Expression, CompiledExpression

public class UserDefinedFunction
extends Function

Author:
wolf

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_NODE_CONSTRUCTOR, IN_PREDICATE, IN_UPDATE, IN_WHERE_CLAUSE, NEED_INDEX_INFO, NO_CONTEXT_ID, SINGLE_STEP_EXECUTION, 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(String varName)
           
 void analyze(AnalyzeContextInfo contextInfo)
          Statically analyze the expression and its subexpressions.
 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.
 int getDependencies()
          Returns Dependency.DEFAULT_DEPENDENCIES.
 Expression getFunctionBody()
           
 List getParameters()
          Return the functions parameters list
 void resetState(boolean postOptimization)
          Called to inform an expression that it should reset to its initial state.
 void setArguments(Sequence[] args, DocumentSet[] contextDocs)
           
 void setFunctionBody(Expression body)
           
 String toString()
           
 
Methods inherited from class org.exist.xquery.Function
createFunction, getArgument, getArgumentCount, getArguments, getASTNode, getCardinality, getName, getParent, getSignature, isCalledAs, returnsType, setArguments, setASTNode, setParent, setPrimaryAxis
 
Methods inherited from class org.exist.xquery.PathExpr
add, add, addPath, addPredicate, dump, getContext, getDocumentSet, getExpression, getLastExpression, getLength, getLiteralValue, getSource, isValid, replaceExpression, replaceLastExpression, reset, 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
 

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(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 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

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 List getParameters()
Return the functions parameters list

Returns:
List of function parameters


Copyright (C) Wolfgang Meier. All rights reserved.