## net.sf.saxon.instruct
Class Element

    java.lang.Object
      |
      +--net.sf.saxon.expr.ComputedExpression
            |
            +--net.sf.saxon.instruct.Instruction
                  |
                  +--net.sf.saxon.instruct.InstructionWithChildren
                        |
                        +--net.sf.saxon.instruct.ElementCreator
                              |
                              +--net.sf.saxon.instruct.Element

All Implemented Interfaces:
  Container, Expression, InstructionInfoProvider, java.io.Serializable, javax.xml.transform.SourceLocator

public class Element
extends ElementCreator

An instruction representing xsl:element element in the stylesheet.

See Also:
  Serialized Form

Field Summary

Fields inherited from class net.sf.saxon.instruct.ElementCreator
`inheritNamespaces, schemaType, useAttributeSets, validation`

Fields inherited from class net.sf.saxon.instruct.InstructionWithChildren
`children`

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
`Element(Expression elementName, Expression namespace, NamespaceResolver nsContext, AttributeSet[] useAttributeSets, 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` `display(int level, NamePool pool, java.io.PrintStream out)` Display this instruction as an expression, for diagnostics
`int` `getInstructionNameCode()` Get the name of this instruction for diagnostic and tracing purposes
`protected int` `getNameCode(XPathContext context)` Callback from the superclass ElementCreator to get the nameCode for the element name
`java.util.Iterator` `iterateSubExpressions()` Get the immediate sub-expressions of this expression.
`protected void` `outputNamespaceNodes(XPathContext context, Receiver out)` Callback to output namespace nodes for the new element.
`protected void` `promoteInst(PromotionOffer offer)` Offer promotion for subexpressions.
`Expression` `simplify(StaticContext env)` Simplify an expression.

Methods inherited from class net.sf.saxon.instruct.ElementCreator
`evaluateItem, getCardinality, getItemType, getValidationMode, processLeavingTail, setValidationMode`

Methods inherited from class net.sf.saxon.instruct.InstructionWithChildren
`displayChildren, getChildren, processChildren, processChildrenLeavingTail, setChildren`

Methods inherited from class net.sf.saxon.instruct.Instruction
`appendItem, assembleParams, assembleTunnelParams, computeCardinality, computeSpecialProperties, dynamicError, dynamicError, effectiveBooleanValue, evaluateAsString, getImplementationMethod, getInstructionInfo, getSourceLocator, 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`

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`

Constructor Detail

### Element

    public Element(Expression elementName,
                   Expression namespace,
                   NamespaceResolver nsContext,
                   AttributeSet[] useAttributeSets,
                   SchemaType schemaType,
                   int validation)

  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 QName
  `namespace` - 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.
  `nsContext` - Saved copy of the static namespace context for the instruction. Can be set to null if namespace is supplied.
  `useAttributeSets` - Array of attribute sets to be expanded
  `schemaType` - The required schema type for the content

Method Detail

### simplify

    public Expression simplify(StaticContext env)
                        throws XPathException

  Description copied from class: `InstructionWithChildren`
  Simplify an expression. This performs any static optimization (by rewriting the expression as a different expression).

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

### analyze

    public Expression analyze(StaticContext env,
                              ItemType contextItemType)
                       throws XPathException

  Description copied from class: `InstructionWithChildren`
  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 `InstructionWithChildren`
  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)

### iterateSubExpressions

    public java.util.Iterator iterateSubExpressions()

  Description copied from class: `InstructionWithChildren`
  Get the immediate sub-expressions of this expression.

  Specified by:
    `iterateSubExpressions` in interface `Expression`
  Overrides:
    `iterateSubExpressions` in class `InstructionWithChildren`
  Returns:
    an iterator containing the sub-expressions of this expression

### promoteInst

    protected void promoteInst(PromotionOffer offer)
                        throws XPathException

  Offer promotion for subexpressions. The offer will be accepted if the subexpression is not dependent on the factors (e.g. the context item) identified in the PromotionOffer. By default the offer is not accepted - this is appropriate in the case of simple expressions such as constant values and variable references where promotion would give no performance advantage. This method is always called at compile time.

  Overrides:
    `promoteInst` in class `InstructionWithChildren`
  Parameters:
    `offer` - details of the offer, for example the offer to move expressions that don't depend on the context to an outer level in the containing expression
  Throws:
    `XPathException` - if any error is detected

### getNameCode

    protected int getNameCode(XPathContext context)
                       throws XPathException,
                              XPathException

  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
    `XPathException`

### outputNamespaceNodes

    protected void outputNamespaceNodes(XPathContext context,
                                        Receiver out)
                                 throws XPathException

  Callback to output namespace nodes for the new element.

  Specified by:
    `outputNamespaceNodes` in class `ElementCreator`
  Parameters:
    `context` - The execution context
    `out` - the Receiver where the namespace nodes are to be written
  Throws:
    `XPathException`

### getInstructionNameCode

    public int getInstructionNameCode()

  Get the name of this instruction for diagnostic and tracing purposes

  Overrides:
    `getInstructionNameCode` in class `Instruction`

### 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