Class ComputedElement
- java.lang.Object
-
- net.sf.saxon.expr.Expression
-
- net.sf.saxon.expr.instruct.Instruction
-
- net.sf.saxon.expr.instruct.ParentNodeConstructor
-
- net.sf.saxon.expr.instruct.ElementCreator
-
- net.sf.saxon.expr.instruct.ComputedElement
-
- All Implemented Interfaces:
ExportAgent,InstructionWithComplexContent,TailCallReturner,ValidatingInstruction,Locatable,IdentityComparable,Traceable
public class ComputedElement extends ElementCreator
An instruction representing an xsl:element element in an XSLT stylesheet, or a computed element constructor in XQuery. (In both cases, if the element name is expressed as a compile-time expression, then a FixedElement instruction is used instead.)- See Also:
FixedElement
-
-
Field Summary
-
Fields inherited from class net.sf.saxon.expr.instruct.ParentNodeConstructor
contentOp, preservingTypes
-
Fields inherited from class net.sf.saxon.expr.Expression
EFFECTIVE_BOOLEAN_VALUE, EVALUATE_METHOD, ITEM_FEED_METHOD, ITERATE_METHOD, MAX_COST, MAX_SEQUENCE_LENGTH, MAX_STRING_LENGTH, PROCESS_METHOD, staticProperties, UNBOUNDED_LOWER, UNBOUNDED_UPPER, UPDATE_METHOD, WATCH_METHOD
-
-
Constructor Summary
Constructors Constructor Description ComputedElement(Expression elementName, Expression namespace, SchemaType schemaType, int validation, boolean inheritNamespaces, boolean allowQName)Create an instruction that creates a new element node
-
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description voidcheckPermittedContents(SchemaType parentType, boolean whole)Check that any elements and attributes constructed or returned by this expression are acceptable in the content model of a given complex type.Expressioncopy(RebindingMap rebindings)Copy an expression.voidexport(ExpressionPresenter out)Diagnostic print of expression structure.NodeNamegetElementName(XPathContext context, NodeInfo copiedNode)Callback from the superclass ElementCreator to get the nameCode for the element nameintgetInstructionNameCode()Get the name of this instruction for diagnostic and tracing purposesItemTypegetItemType()Get the item type of the value returned by this instructionExpressiongetNameExp()Get the expression used to compute the element nameExpressiongetNamespaceExp()Get the expression used to compute the namespace URINamespaceResolvergetNamespaceResolver()Get the namespace resolver that provides the namespace bindings defined in the static contextjava.lang.StringgetNewBaseURI(XPathContext context, NodeInfo copiedNode)Get the base URI for the element being constructedbooleanisAllowNameAsQName()Ask whether the name can be supplied as a QName.java.lang.Iterable<Operand>operands()Get the immediate sub-expressions of this expression, with information about the relationship of each expression to its parent expression.voidoutputNamespaceNodes(Outputter out, NodeName nodeName, NodeInfo copiedNode)Callback to output namespace nodes for the new element.protected voidsetNameExp(Expression elementName)protected voidsetNamespaceExp(Expression namespace)Expressionsimplify()Simplify an expression.ExpressiontypeCheck(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo)Perform type checking of an expression and its subexpressions.-
Methods inherited from class net.sf.saxon.expr.instruct.ElementCreator
checkContentSequence, computeSpecialProperties, getCardinality, getImplementationMethod, getStreamerName, isBequeathNamespacesToChildren, isInheritNamespacesFromParent, processLeavingTail, processLeavingTail, setBequeathNamespacesToChildren, setInheritanceFlags, setInheritNamespacesFromParent, suppressValidation
-
Methods inherited from class net.sf.saxon.expr.instruct.ParentNodeConstructor
addToPathMap, allowExtractingCommonSubexpressions, alwaysCreatesNewNodes, computeCardinality, getContentExpression, getContentOperand, getSchemaType, getValidationAction, getValidationOptions, isLocal, isPreservingTypes, mayCreateNewNodes, optimize, setContentExpression, setNoNeedToStrip, setValidationAction
-
Methods inherited from class net.sf.saxon.expr.instruct.Instruction
assembleParams, assembleTunnelParams, dynamicError, evaluateAsString, evaluateItem, getExpressionName, getNetCost, getSourceLocator, isInstruction, isXSLT, iterate, process, someOperandCreatesNewNodes
-
Methods inherited from class net.sf.saxon.expr.Expression
adoptChildExpression, checkedOperands, checkForUpdatingSubexpressions, computeDependencies, computeHashCode, computeStaticProperties, dynamicError, effectiveBooleanValue, equals, evaluatePendingUpdates, explain, getConfiguration, getCost, getDependencies, getEvaluationMethod, getExtraProperty, getIntegerBounds, getInterpretedExpression, getIntrinsicDependencies, getLocalRetainedStaticContext, getLocation, getObjectName, getPackageData, getParentExpression, getProperties, getProperty, getRetainedStaticContext, getScopingExpression, getSlotsUsed, getSpecialProperties, getStaticBaseURI, getStaticBaseURIString, getStaticType, getStaticUType, getTracingTag, hasCompatibleStaticContext, hashCode, hasSpecialProperty, hasVariableBinding, identityHashCode, implementsStaticTypeCheck, isCallOn, isEqual, isIdentical, isLiftable, isMultiThreaded, isStaticPropertiesKnown, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, markTailFunctionCalls, operandList, operandSparseList, optimizeChildren, prepareForStreaming, resetLocalStaticProperties, restoreParentPointers, setEvaluationMethod, setExtraProperty, setFiltered, setFlattened, setLocation, setParentExpression, setRetainedStaticContext, setRetainedStaticContextLocally, setRetainedStaticContextThoroughly, setStaticProperty, simplifyChildren, staticTypeCheck, toPattern, toShortString, toString, typeCheckChildren, typeError, unordered, verifyParentPointers
-
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
-
Methods inherited from interface net.sf.saxon.trace.Traceable
gatherProperties
-
-
-
-
Constructor Detail
-
ComputedElement
public ComputedElement(Expression elementName, Expression namespace, SchemaType schemaType, int validation, boolean inheritNamespaces, boolean allowQName)
Create an instruction that creates a new element node- Parameters:
elementName- Expression that evaluates to produce the name of the element node as a lexical QNamenamespace- Expression that evaluates to produce the namespace URI of the element node. Set to null if the namespace is to be deduced from the prefix of the elementName.schemaType- The required schema type for the contentvalidation- Required validation mode (e.g. STRICT, LAX, SKIP)inheritNamespaces- true if child elements automatically inherit the namespaces of their parentallowQName- True if the elementName expression is allowed to return a QNameValue; false if
-
-
Method Detail
-
getNameExp
public Expression getNameExp()
Get the expression used to compute the element name- Returns:
- the expression used to compute the element name
-
getNamespaceExp
public Expression getNamespaceExp()
Get the expression used to compute the namespace URI- Returns:
- the expression used to compute the namespace URI
-
setNameExp
protected void setNameExp(Expression elementName)
-
setNamespaceExp
protected void setNamespaceExp(Expression namespace)
-
operands
public java.lang.Iterable<Operand> operands()
Description copied from class:ExpressionGet the immediate sub-expressions of this expression, with information about the relationship of each expression to its parent expression. Default implementation works off the results of iterateSubExpressions()If the expression is a Callable, then it is required that the order of the operands returned by this function is the same as the order of arguments supplied to the corresponding call() method.
- Specified by:
operandsin classInstruction- Returns:
- an iterator containing the sub-expressions of this expression
-
getNamespaceResolver
public NamespaceResolver getNamespaceResolver()
Get the namespace resolver that provides the namespace bindings defined in the static context- Returns:
- the namespace resolver
-
simplify
public Expression simplify() throws XPathException
Description copied from class:ExpressionSimplify an expression. This performs any static optimization (by rewriting the expression as a different expression). The default implementation simplifies its operands.- Overrides:
simplifyin classExpression- Returns:
- the simplified expression (or the original if unchanged, or if modified in-situ)
- Throws:
XPathException- if an error is discovered during expression rewriting
-
typeCheck
public Expression typeCheck(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo) throws XPathException
Description copied from class:ExpressionPerform type checking of an expression and its subexpressions. This is the second phase of static optimization.This checks statically that the operands of the expression have the correct type; if necessary it generates code to do run-time type checking or type conversion. A static type error is reported only if execution cannot possibly succeed, that is, if a run-time type error is inevitable. The call may return a modified form of the expression.
This method is called after all references to functions and variables have been resolved to the declaration of the function or variable. However, the types of such functions and variables may not be accurately known if they have not been explicitly declared.
- Overrides:
typeCheckin classParentNodeConstructor- Parameters:
visitor- an expression visitorcontextInfo- Information available statically about the context item: whether it is (possibly) absent; its static type; its streaming posture.- Returns:
- the original expression, rewritten to perform necessary run-time type checks, and to perform other type-related optimizations
- Throws:
XPathException- if an error is discovered during this phase (typically a type error)
-
copy
public Expression copy(RebindingMap rebindings)
Copy an expression. This makes a deep copy.- Specified by:
copyin classExpression- Parameters:
rebindings- a mutable list of (old binding, new binding) pairs that is used to update the bindings held in any local variable references that are copied.- Returns:
- the copy of the original expression
-
getItemType
public ItemType getItemType()
Get the item type of the value returned by this instruction- Overrides:
getItemTypein classElementCreator- Returns:
- the item type
-
checkPermittedContents
public void checkPermittedContents(SchemaType parentType, boolean whole) throws XPathException
Check that any elements and attributes constructed or returned by this expression are acceptable in the content model of a given complex type. It's always OK to say yes, since the check will be repeated at run-time. The process of checking element and attribute constructors against the content model of a complex type also registers the type of content expected of those constructors, so the static validation can continue recursively.- Overrides:
checkPermittedContentsin classExpression- Parameters:
parentType- the "given complex type": the method is checking that the nodes returned by this expression are acceptable members of the content model of this typewhole- if true, we want to check that the value of this expression satisfies the content model as a whole; if false we want to check that the value of the expression is acceptable as one part of the content- Throws:
XPathException- if the value delivered by this expression cannot be part of the content model of the given type
-
getElementName
public NodeName getElementName(XPathContext context, NodeInfo copiedNode) throws XPathException
Callback from the superclass ElementCreator to get the nameCode for the element name- Specified by:
getElementNamein classElementCreator- Parameters:
context- The evaluation context (not used)copiedNode- Not applicable to this overload- Returns:
- the name code for the element name
- Throws:
XPathException- if a failure occurs
-
isAllowNameAsQName
public boolean isAllowNameAsQName()
Ask whether the name can be supplied as a QName. In practice this is true for XQuery, false for XSLT- Returns:
- true if the name can be supplied as a QName
-
getNewBaseURI
public java.lang.String getNewBaseURI(XPathContext context, NodeInfo copiedNode)
Description copied from class:ElementCreatorGet the base URI for the element being constructed- Specified by:
getNewBaseURIin classElementCreator- Parameters:
context- the XPath dynamic evaluation contextcopiedNode- the node being copied (for xsl:copy), otherwise null- Returns:
- the base URI of the constructed element
-
outputNamespaceNodes
public void outputNamespaceNodes(Outputter out, NodeName nodeName, NodeInfo copiedNode) throws XPathException
Callback to output namespace nodes for the new element.- Specified by:
outputNamespaceNodesin classElementCreator- Parameters:
out- the Outputter where the namespace nodes are to be writtennodeName- The name of the element node being outputcopiedNode- Where this is a copied node, the node being copied- Throws:
XPathException- if a dynamic error occurs
-
getInstructionNameCode
public int getInstructionNameCode()
Get the name of this instruction for diagnostic and tracing purposes- Overrides:
getInstructionNameCodein classInstruction- Returns:
- a code identifying the instruction: typically but not always the fingerprint of a name in the XSLT namespace
-
export
public void export(ExpressionPresenter out) throws XPathException
Diagnostic print of expression structure. The abstract expression tree is written to the supplied output destination.- Specified by:
exportin interfaceExportAgent- Specified by:
exportin classExpression- Parameters:
out- the expression presenter used to display the structure- Throws:
XPathException- if the export fails, for example if an expression is found that won't work in the target environment.
-
-