## net.sf.saxon.expr.instruct
Class GlobalParam

    java.lang.Object
      net.sf.saxon.expr.Expression
          net.sf.saxon.expr.instruct.Instruction
              net.sf.saxon.expr.instruct.GeneralVariable
                  net.sf.saxon.expr.instruct.GlobalVariable
                      net.sf.saxon.expr.instruct.GlobalParam

All Implemented Interfaces:
  Serializable, SourceLocator, LocationProvider, SaxonLocator, Binding, Container, EvaluableItem, TailCallReturner, SequenceIterable, InstructionInfo, Locator

    public final class GlobalParam

extends GlobalVariable

The compiled form of a global xsl:param element in an XSLT stylesheet or an external variable declared in the prolog of a Query.
The xsl:param element in XSLT has mandatory attribute name and optional attribute select. It can also be specified as required="yes" or required="no". In standard XQuery 1.0 external variables are always required, and no default value can be specified; but Saxon provides an extension pragma that allows a query to specify a default. XQuery 1.1 adds standard syntax for defining a default value.

See Also:
  Serialized Form

Field Summary

Fields inherited from class net.sf.saxon.expr.instruct.GeneralVariable
`evaluationMode, referenceCount, slotNumber, variableQName`

Fields inherited from class net.sf.saxon.expr.Expression
`EVALUATE_METHOD, EVENT_FEED_METHOD, ITEM_FEED_METHOD, ITERATE_METHOD, locationId, PROCESS_METHOD, PUSH_SELECTION, staticProperties, WATCH_METHOD`

Constructor Summary
`GlobalParam()`

Method Summary
`ValueRepresentation` `evaluateVariable(XPathContext context)` Evaluate the variable
`int` `getInstructionNameCode()` Get the name of this instruction for diagnostic and tracing purposes

Methods inherited from class net.sf.saxon.expr.instruct.GlobalVariable
`actuallyEvaluate, getContainerGranularity, getExecutable, getHostLanguage, getSelectValue, isGlobal, isIndexedVariable, lookForCycles, processLeavingTail, setContainsLocals, setDependencies, setExecutable, setIndexedVariable`

Methods inherited from class net.sf.saxon.expr.instruct.GeneralVariable

`copy, evaluateItem, explain, getCardinality, getEvaluationMode, getItemType, getLocalSlotNumber, getRequiredType, getSelectExpression, getSlotNumber, getVariableQName, init, isAssignable, isImplicitlyRequiredParam, isRequiredParam, isTunnelParam, iterate, iterateSubExpressions, optimize, promoteInst, replaceSubExpression, setAssignable, setImplicitlyRequiredParam, setReferenceCount, setRequiredParam, setRequiredType, setSelectExpression, setSlotNumber, setTunnel, setVariableQName, simplify, typeCheck`

Methods inherited from class net.sf.saxon.expr.instruct.Instruction
`assembleParams, assembleTunnelParams, computeCardinality, computeSpecialProperties, createsNewNodes, dynamicError, evaluateAsString, getConstructType, getExpressionName, getImplementationMethod, getInstructionName, getIteratorFromProcessMethod, getSourceLocator, isXSLT, process, promote`

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

`addToPathMap, adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, effectiveBooleanValue, evaluatePendingUpdates, explain, getColumnNumber, getColumnNumber, getContainer, getDependencies, getEvaluationMethod, getIntrinsicDependencies, getLineNumber, getLineNumber, getLocationId, getLocationProvider, getObjectName, getProperties, getProperty, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, getSystemId, hasLoopingSubexpression, implementsStaticTypeCheck, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, iterateEvents, iterateSameFocusSubExpressions, markTailFunctionCalls, resetLocalStaticProperties, setContainer, setEvaluationMethod, setFiltered, setFlattened, setLocationId, staticTypeCheck, suppressValidation, toString, typeError`

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

Methods inherited from interface net.sf.saxon.expr.Container
`getLocationProvider`

Methods inherited from interface javax.xml.transform.SourceLocator
`getColumnNumber, getLineNumber, getPublicId, getSystemId`

Constructor Detail

### GlobalParam

    public GlobalParam()

Method Detail

### getInstructionNameCode

    public int getInstructionNameCode()

  Get the name of this instruction for diagnostic and tracing purposes

  Overrides:
    `getInstructionNameCode` in class `GeneralVariable`
  Returns:
    the name of this instruction, as a name pool name code

### evaluateVariable

    public ValueRepresentation evaluateVariable(XPathContext context)
                                         throws XPathException

  Evaluate the variable

  Specified by:
    `evaluateVariable` in interface `Binding`
  Overrides:
    `evaluateVariable` in class `GlobalVariable`
  Parameters:
    `context` - the XPath dynamic evaluation context
  Returns:
    the result of evaluating the variable
  Throws:
    `XPathException`

Copyright (c) 2004-2010 Saxonica Limited. All rights reserved.