## net.sf.saxon.instruct
Class ProcessingInstruction

    java.lang.Object
      net.sf.saxon.expr.ComputedExpression
          net.sf.saxon.instruct.Instruction
              net.sf.saxon.instruct.SimpleNodeConstructor
                  net.sf.saxon.instruct.ProcessingInstruction

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

public class ProcessingInstruction
extends SimpleNodeConstructor

An xsl:processing-instruction element in the stylesheet.

See Also:
  Serialized Form

Field Summary

Fields inherited from class net.sf.saxon.instruct.SimpleNodeConstructor
`select`

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
`ProcessingInstruction(Expression name)` Create an xsl:processing-instruction instruction

Method Summary
`protected java.lang.String` `checkContent(java.lang.String data, XPathContext context)` Check the content of the node, and adjust it if necessary
`void` `display(int level, NamePool pool, java.io.PrintStream out)` Display this instruction as an expression, for diagnostics
`protected int` `evaluateNameCode(XPathContext context)`
`int` `getCardinality()` Determine the static cardinality of the expression.
`int` `getDependencies()` Determine which aspects of the context the expression depends on.
`int` `getInstructionNameCode()` Get the name of this instruction for diagnostic and tracing purposes
`ItemType` `getItemType(TypeHierarchy th)` Get the item type of the items returned by evaluating this instruction
`java.util.Iterator` `iterateSubExpressions()` Get the immediate sub-expressions of this expression.
`void` `localTypeCheck(StaticContext env, ItemType contextItemType)`
`TailCall` `processLeavingTail(XPathContext context)` Process this instruction, that is, produce a processing-instruction node in the result sequence.
`protected void` `promoteInst(PromotionOffer offer)` Offer promotion for subexpressions.
`Expression` `simplify(StaticContext env)` Simplify an expression.

Methods inherited from class net.sf.saxon.instruct.SimpleNodeConstructor
`computeSpecialProperties, createsNewNodes, evaluateItem, expandChildren, getSelect, iterate, optimize, setSelect, typeCheck`

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

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

`adoptChildExpression, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, dynamicError, effectiveBooleanValue, getColumnNumber, getConstructType, getExecutable, getIntrinsicDependencies, getLineNumber, getLocationId, getLocationProvider, getParentExpression, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasBadParentPointer, markTailFunctionCalls, resetStaticProperties, setLocationId, setParentExpression, suppressValidation, 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`

Constructor Detail

### ProcessingInstruction

    public ProcessingInstruction(Expression name)

  Create an xsl:processing-instruction instruction

Parameters:
  `name` - the expression used to compute the name of the generated processing-instruction

Method Detail

### getInstructionNameCode

    public int getInstructionNameCode()

  Get the name of this instruction for diagnostic and tracing purposes

  Overrides:
    `getInstructionNameCode` in class `Instruction`
  Returns:
    the string "xsl:processing-instruction"

### getItemType

    public ItemType getItemType(TypeHierarchy th)

  Description copied from class: `Instruction`
  Get the item type of the items returned by evaluating this instruction

  Specified by:
    `getItemType` in interface `Expression`
  Overrides:
    `getItemType` in class `Instruction`
  Parameters:
    `th` -
  Returns:
    the static item type of the instruction

### getCardinality

    public int getCardinality()

  Description copied from class: `ComputedExpression`
  Determine the static cardinality of the expression. This establishes how many items there will be in the result of the expression, at compile time (i.e., without actually evaluating the result.

  Specified by:
    `getCardinality` in interface `Expression`
  Overrides:
    `getCardinality` in class `ComputedExpression`
  Returns:
    one of the values Cardinality.ONE_OR_MORE, Cardinality.ZERO_OR_MORE, Cardinality.EXACTLY_ONE, Cardinality.ZERO_OR_ONE, Cardinality.EMPTY. This default implementation returns ZERO_OR_MORE (which effectively gives no information).

### simplify

    public Expression simplify(StaticContext env)
                        throws XPathException

  Description copied from class: `Instruction`
  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 `SimpleNodeConstructor`
  Throws:
    `XPathException`

### localTypeCheck

    public void localTypeCheck(StaticContext env,
                               ItemType contextItemType)
                        throws XPathException

  Specified by:
    `localTypeCheck` in class `SimpleNodeConstructor`
  Throws:
    `XPathException`

### getDependencies

    public int getDependencies()

  Description copied from class: `ComputedExpression`
  Determine which aspects of the context the expression depends on. The result is a bitwise-or'ed value composed from constants such as XPathContext.VARIABLES and XPathContext.CURRENT_NODE. The default implementation combines the intrinsic dependencies of this expression with the dependencies of the subexpressions, computed recursively. This is overridden for expressions such as FilterExpression where a subexpression's dependencies are not necessarily inherited by the parent expression.

  Specified by:
    `getDependencies` in interface `Expression`
  Overrides:
    `getDependencies` in class `ComputedExpression`
  Returns:
    a set of bit-significant flags identifying the dependencies of the expression

### iterateSubExpressions

    public java.util.Iterator iterateSubExpressions()

  Description copied from class: `ComputedExpression`
  Get the immediate sub-expressions of this expression. Default implementation returns a zero-length array, appropriate for an expression that has no sub-expressions.

  Specified by:
    `iterateSubExpressions` in interface `Expression`
  Overrides:
    `iterateSubExpressions` in class `SimpleNodeConstructor`

### 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 `SimpleNodeConstructor`
  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

### processLeavingTail

    public TailCall processLeavingTail(XPathContext context)
                                throws XPathException

  Process this instruction, that is, produce a processing-instruction node in the result sequence.

  Specified by:
    `processLeavingTail` in interface `TailCallReturner`
  Specified by:
    `processLeavingTail` in class `Instruction`
  Parameters:
    `context` - the dynamic context of this transformation
  Returns:
    always returns null in this implementation
  Throws:
    `XPathException` - if any non-recoverable dynamic error occurs

### checkContent

    protected java.lang.String checkContent(java.lang.String data,
                                            XPathContext context)
                                     throws DynamicError

  Check the content of the node, and adjust it if necessary

  Overrides:
    `checkContent` in class `SimpleNodeConstructor`
  Parameters:
    `data` - the supplied content
    `context` - the dynamic context
  Returns:
    the original content, unless adjustments are needed
  Throws:
    `DynamicError` - if the content is invalid

### evaluateNameCode

    protected int evaluateNameCode(XPathContext context)
                            throws XPathException

  Overrides:
    `evaluateNameCode` in class `SimpleNodeConstructor`
  Throws:
    `XPathException`

### display

    public void display(int level,
                        NamePool pool,
                        java.io.PrintStream out)

  Description copied from class: `SimpleNodeConstructor`
  Display this instruction as an expression, for diagnostics

  Specified by:
    `display` in interface `Expression`
  Overrides:
    `display` in class `SimpleNodeConstructor`