Class ValueOf

  • All Implemented Interfaces:
    java.io.Serializable, javax.xml.transform.SourceLocator, LocationProvider, SaxonLocator, EvaluableItem, SequenceIterable, TailCallReturner, InstructionInfo, org.xml.sax.Locator

    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:
    Serialized Form
    • Constructor Detail

      • ValueOf

        public ValueOf​(Expression select,
                       boolean disable,
                       boolean noNodeIfEmpty)
        Create a new ValueOf expression
        Parameters:
        select - the select expression
        disable - true if disable-output-escaping is in force
        noNodeIfEmpty - true if the instruction is to return () if the select expression is (), false if it is to return an empty text node
    • Method Detail

      • 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
        Returns:
        true if this derives from xsl:number
      • getInstructionNameCode

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

        public int getOptions()
        Test for any special options such as disable-output-escaping
        Returns:
        any special options
      • isDisableOutputEscaping

        public boolean isDisableOutputEscaping()
        Test whether disable-output-escaping was requested
        Returns:
        true if disable-output-escaping was requested
      • getItemType

        public ItemType getItemType​(TypeHierarchy th)
        Description copied from class: Instruction
        Get the item type of the items returned by evaluating this instruction
        Overrides:
        getItemType in class Instruction
        Parameters:
        th - the type hierarchy cache
        Returns:
        the static item type of the instruction
      • copy

        public Expression copy()
        Copy an expression. This makes a deep copy.
        Specified by:
        copy in class Expression
        Returns:
        the copy of the original expression
      • 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.
        Overrides:
        checkPermittedContents in class Expression
        Parameters:
        parentType - The schema type
        env - the static context
        whole - true if this expression is to account for the whole value of the type
        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.
        Parameters:
        env - the static evaluation context
        Returns:
        the converted expression
      • explain

        public void explain​(ExpressionPresenter out)
        Diagnostic print of expression structure. The abstract expression tree is written to the supplied output destination.
        Specified by:
        explain in class Expression
        Parameters:
        out - the expression presenter used to display the structure