Class ValueOf

All Implemented Interfaces:
Serializable, SourceLocator, Container, Expression, TailCallReturner, InstructionInfoProvider

public final class ValueOf extends SimpleNodeConstructor
An xsl:value-of element in the stylesheet.
The xsl:value-of element takes attributes:
  • a mandatory attribute select="expression". This must be a valid String expression
  • an optional disable-output-escaping attribute, value "yes" or "no"
  • an optional separator attribute. This is handled at compile-time: if the separator attribute is present, the select expression passed in here will be a call to the string-join() function.
See Also:
  • Constructor Details

    • ValueOf

      public ValueOf(Expression select, boolean disable, boolean noNodeIfEmpty)
  • Method Details

    • setIsNumberingInstruction

      public void setIsNumberingInstruction()
      Indicate that this is really an xsl:nunber instruction
    • isNumberingInstruction

      public boolean isNumberingInstruction()
      Determine whether this is really an xsl:number instruction
    • getInstructionNameCode

      public int getInstructionNameCode()
      Get the name of this instruction for diagnostic and tracing purposes
      Overrides:
      getInstructionNameCode in class Instruction
    • 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
    • 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
    • computeCardinality

      public int computeCardinality()
      Description copied from class: Instruction
      Get the cardinality of the sequence returned by evaluating this instruction
      Overrides:
      computeCardinality in class Instruction
      Returns:
      the static cardinality
    • localTypeCheck

      public void localTypeCheck(StaticContext env, ItemType contextItemType)
      Specified by:
      localTypeCheck in class SimpleNodeConstructor
    • checkPermittedContents

      public void checkPermittedContents(SchemaType parentType, StaticContext env, boolean whole) throws XPathException
      Check statically that the results of the expression are capable of constructing the content of a given schema type.
      Specified by:
      checkPermittedContents in interface Expression
      Overrides:
      checkPermittedContents in class ComputedExpression
      Parameters:
      parentType - The schema type
      env - the static context
      whole -
      Throws:
      XPathException - if the expression doesn't match the required content type
    • convertToStringJoin

      public Expression convertToStringJoin(StaticContext env)
      Convert this value-of instruction to an expression that delivers the string-value of the resulting text node. This will often be a call on the string-join function.
    • processLeavingTail

      public TailCall processLeavingTail(XPathContext context) throws XPathException
      Process this instruction, sending the resulting text node to the current output destination
      Specified by:
      processLeavingTail in interface TailCallReturner
      Specified by:
      processLeavingTail in class Instruction
      Parameters:
      context -
      Returns:
      Always returns null
      Throws:
      XPathException
    • evaluateItem

      public Item evaluateItem(XPathContext context) throws XPathException
      Evaluate this expression, returning the resulting text node to the caller
      Specified by:
      evaluateItem in interface Expression
      Overrides:
      evaluateItem in class SimpleNodeConstructor
      Parameters:
      context -
      Returns:
      the parentless text node that results from evaluating this instruction, or null to represent an empty sequence
      Throws:
      XPathException
    • display

      public void display(int level, PrintStream out, Configuration config)
      Display this instruction as an expression, for diagnostics
      Specified by:
      display in interface Expression
      Overrides:
      display in class SimpleNodeConstructor
      Parameters:
      level - indentation level for this expression
      out - Output destination
      config -