net.sf.saxon.instruct

Class QuerySimpleContentConstructor

java.lang.Object

net.sf.saxon.expr.ComputedExpression

net.sf.saxon.instruct.SimpleContentConstructor

net.sf.saxon.instruct.QuerySimpleContentConstructor

All Implemented Interfaces:

java.io.Serializable, javax.xml.transform.SourceLocator, Container, Expression, InstructionInfoProvider

public class QuerySimpleContentConstructor
extends SimpleContentConstructor

This class implements the rules for an XQuery simple content constructor, which are used in constructing the string value of an attribute node, text node, comment node, etc, from the value of the select expression or the contained sequence constructor. These differ slightly from the XSLT rules implemented in the superclass - specifically, the sequence is simply atomized, whereas XSLT takes special steps to concatenate adjacent text nodes before inserting separators.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
(package private) boolean	noNodeIfEmpty

Fields inherited from class net.sf.saxon.instruct.SimpleContentConstructor

isAtomic, isSingleton, select, separator

Fields inherited from class net.sf.saxon.expr.ComputedExpression

locationId, staticProperties

Fields inherited from interface net.sf.saxon.expr.Expression

EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD

Constructor Summary

Constructors

Constructor and Description
QuerySimpleContentConstructor(Expression select, Expression separator, boolean noNodeIfEmpty)

Method Summary

Modifier and Type	Method and Description
protected int	computeCardinality() Compute the cardinality of the result of the expression.
Item	evaluateItem(XPathContext context) Evaluate an expression as a single item.
java.lang.CharSequence	expandChildren(XPathContext context) Expand the stylesheet elements subordinate to this one, returning the result as a string.

Methods inherited from class net.sf.saxon.instruct.SimpleContentConstructor

display, getImplementationMethod, getItemType, iterateSubExpressions, optimize, promote, replaceSubExpression, simplify, typeCheck

Methods inherited from class net.sf.saxon.expr.ComputedExpression

adoptChildExpression, checkPermittedContents, computeDependencies, computeSpecialProperties, computeStaticProperties, doPromotion, dynamicError, effectiveBooleanValue, evaluateAsString, getCardinality, getColumnNumber, getConstructType, getDependencies, getExecutable, getHostLanguage, getInstructionInfo, getIntrinsicDependencies, getLineNumber, getLocationId, getLocationProvider, getParentExpression, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasBadParentPointer, iterate, markTailFunctionCalls, process, resetStaticProperties, setLocationId, setParentExpression, setParentExpression, suppressValidation, typeError

Methods inherited from class java.lang.Object

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

Field Detail

noNodeIfEmpty

boolean noNodeIfEmpty

Constructor Detail

QuerySimpleContentConstructor

public QuerySimpleContentConstructor(Expression select,
                                     Expression separator,
                                     boolean noNodeIfEmpty)

Method Detail

computeCardinality

protected int computeCardinality()

Compute the cardinality of the result of the expression.

Overrides:

computeCardinality in class SimpleContentConstructor

Returns:

the cardinality, @link {StaticProperty.EXACTLY_ONE}

expandChildren

public java.lang.CharSequence expandChildren(XPathContext context)
                                      throws XPathException

Expand the stylesheet elements subordinate to this one, returning the result as a string. The expansion must not generate any element or attribute nodes.

Parameters:

context - The dynamic context for the transformation

Throws:

XPathException

evaluateItem

public Item evaluateItem(XPathContext context)
                  throws XPathException

Evaluate an expression as a single item. This always returns either a single Item or null (denoting the empty sequence). No conversion is done. This method should not be used unless the static type of the expression is a subtype of "item" or "item?": that is, it should not be called if the expression may return a sequence. There is no guarantee that this condition will be detected.

Specified by:

evaluateItem in interface Expression

Overrides:

evaluateItem in class SimpleContentConstructor

Parameters:

context - The context in which the expression is to be evaluated

Returns:

the node or atomic value that results from evaluating the expression; or null to indicate that the result is an empty sequence

Throws:

XPathException - if any dynamic error occurs evaluating the expression