net.sf.saxon.instruct
Class FixedElement

java.lang.Object
  extended bynet.sf.saxon.expr.ComputedExpression
      extended bynet.sf.saxon.instruct.Instruction
          extended bynet.sf.saxon.instruct.ElementCreator
              extended bynet.sf.saxon.instruct.FixedElement
All Implemented Interfaces:
Container, Expression, InstructionInfoProvider, java.io.Serializable, javax.xml.transform.SourceLocator

public class FixedElement
extends ElementCreator

An instruction that creates an element node whose name is known statically. Used for literal results elements in XSLT, for direct element constructors in XQuery, and for xsl:element in cases where the name and namespace are known statically.

See Also:
Serialized Form

Field Summary
protected  int[] namespaceCodes
           
 
Fields inherited from class net.sf.saxon.instruct.ElementCreator
content, inheritNamespaces, schemaType, useAttributeSets, validation
 
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
FixedElement(int nameCode, int[] namespaceCodes, AttributeSet[] useAttributeSets, boolean inheritNamespaces, SchemaType schemaType, int validation)
          Create an instruction that creates a new element node
 
Method Summary
 Expression analyze(StaticContext env, ItemType contextItemType)
          Perform static analysis of an expression and its subexpressions.
 void checkPermittedContents(SchemaType parentType, StaticContext env, 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.
 void display(int level, NamePool pool, java.io.PrintStream out)
          Display this instruction as an expression, for diagnostics
 InstructionInfo getInstructionInfo()
          Get InstructionInfo for this expression
 ItemType getItemType()
          Get the type of the item returned by this instruction
protected  int getNameCode(XPathContext context)
          Callback from the superclass ElementCreator to get the nameCode for the element name
protected  void outputNamespaceNodes(XPathContext context, Receiver out)
          Callback from the superclass ElementCreator to output the namespace nodes
 Expression simplify(StaticContext env)
          Simplify an expression.
 
Methods inherited from class net.sf.saxon.instruct.ElementCreator
computeSpecialProperties, createsNewNodes, evaluateItem, getCardinality, getImplementationMethod, getValidationMode, iterateSubExpressions, processLeavingTail, promoteInst, setContent, setValidationMode
 
Methods inherited from class net.sf.saxon.instruct.Instruction
appendItem, assembleParams, assembleTunnelParams, computeCardinality, dynamicError, dynamicError, effectiveBooleanValue, evaluateAsString, getInstructionNameCode, getSourceLocator, isXSLT, iterate, process, promote
 
Methods inherited from class net.sf.saxon.expr.ComputedExpression
adoptChildExpression, computeDependencies, computeStaticProperties, dynamicError, dynamicError, getColumnNumber, getConstructType, getDependencies, getExecutable, getIntrinsicDependencies, getLineNumber, getLocationId, getParentExpression, getPublicId, getSpecialProperties, getSystemId, markTailFunctionCalls, resetStaticProperties, setLocationId, setParentExpression, typeError, typeError
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface javax.xml.transform.SourceLocator
getColumnNumber, getLineNumber, getPublicId, getSystemId
 

Field Detail

namespaceCodes

protected int[] namespaceCodes
Constructor Detail

FixedElement

public FixedElement(int nameCode,
                    int[] namespaceCodes,
                    AttributeSet[] useAttributeSets,
                    boolean inheritNamespaces,
                    SchemaType schemaType,
                    int validation)
Create an instruction that creates a new element node

Parameters:
nameCode - Represents the name of the element node
namespaceCodes - List of namespaces to be added to the element node. May be null if none are required.
useAttributeSets - Array of attribute sets to be expanded. May be null if none are required.
inheritNamespaces - true if the children of this element are to inherit its namespaces
schemaType - Type annotation for the new element node
Method Detail

getInstructionInfo

public InstructionInfo getInstructionInfo()
Description copied from class: ComputedExpression
Get InstructionInfo for this expression

Specified by:
getInstructionInfo in interface InstructionInfoProvider
Overrides:
getInstructionInfo in class Instruction

simplify

public Expression simplify(StaticContext env)
                    throws XPathException
Simplify an expression. This performs any static optimization (by rewriting the expression as a different expression). The default implementation does nothing.

Specified by:
simplify in interface Expression
Overrides:
simplify in class ElementCreator
Returns:
the simplified expression
Throws:
XPathException - if an error is discovered during expression rewriting

analyze

public Expression analyze(StaticContext env,
                          ItemType contextItemType)
                   throws XPathException
Perform static analysis of an expression and its subexpressions.

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 will only be accurately known if they have been explicitly declared.

Specified by:
analyze in interface Expression
Overrides:
analyze in class ElementCreator
Parameters:
env - the static context of the expression
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)

getItemType

public ItemType getItemType()
Get the type of the item returned by this instruction

Specified by:
getItemType in interface Expression
Overrides:
getItemType in class ElementCreator
Returns:
the item type

getNameCode

protected int getNameCode(XPathContext context)
Callback from the superclass ElementCreator to get the nameCode for the element name

Specified by:
getNameCode in class ElementCreator
Parameters:
context - The evaluation context (not used)
Returns:
the name code for the element name

checkPermittedContents

public void checkPermittedContents(SchemaType parentType,
                                   StaticContext env,
                                   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.

Specified by:
checkPermittedContents in interface Expression
Overrides:
checkPermittedContents in class ComputedExpression
Throws:
XPathException

outputNamespaceNodes

protected void outputNamespaceNodes(XPathContext context,
                                    Receiver out)
                             throws XPathException
Callback from the superclass ElementCreator to output the namespace nodes

Specified by:
outputNamespaceNodes in class ElementCreator
Parameters:
context - The evaluation context (not used)
out - The receiver to handle the output
Throws:
XPathException

display

public void display(int level,
                    NamePool pool,
                    java.io.PrintStream out)
Display this instruction as an expression, for diagnostics

Parameters:
level - indentation level for this expression
pool - NamePool used to expand any names appearing in the expression
out - Output destination