Class ElementCreator

All Implemented Interfaces:
Serializable, SourceLocator, LocationProvider, SaxonLocator, DivisibleInstruction, TailCallReturner, ValidatingInstruction, InstructionInfo, Locator
Direct Known Subclasses:
ComputedElement, Copy, FixedElement

public abstract class ElementCreator extends ParentNodeConstructor
An instruction that creates an element node. There are two subtypes, FixedElement for use where the name is known statically, and Element where it is computed dynamically. To allow use in both XSLT and XQuery, the class acts both as an Instruction and as an Expression.
See Also:
  • Field Details

    • inheritNamespaces

      protected boolean inheritNamespaces
      The inheritNamespaces flag indicates that the namespace nodes on the element created by this instruction are to be inherited (copied) on the children of this element. That is, if this flag is false, the child elements must carry a namespace undeclaration for all the namespaces on the parent, unless they are redeclared in some way.
  • Constructor Details

    • ElementCreator

      public ElementCreator()
      Construct an ElementCreator. Exists for the benefit of subclasses.
  • Method Details

    • getItemType

      public ItemType getItemType(TypeHierarchy th)
      Get the item type of the value returned by this instruction
      Overrides:
      getItemType in class Instruction
      Parameters:
      th - the type hierarchy cache
      Returns:
      the item type
    • isInheritNamespaces

      public boolean isInheritNamespaces()
      Determine whether the inherit namespaces flag is set
      Returns:
      true if namespaces constructed on a parent element are to be inherited by its children
    • computeSpecialProperties

      public int computeSpecialProperties()
      Get the static properties of this expression (other than its type). The result is bit-signficant. These properties are used for optimizations. In general, if property bit is set, it is true, but if it is unset, the value is unknown.
      Overrides:
      computeSpecialProperties in class Instruction
      Returns:
      a set of flags indicating static properties of this expression
    • suppressValidation

      public void suppressValidation(int parentValidationMode)
      Suppress validation on contained element constructors, on the grounds that the parent element is already performing validation. The default implementation does nothing.
      Overrides:
      suppressValidation in class Expression
      Parameters:
      parentValidationMode - the kind of validation being performed on the parent expression
    • checkContentSequence

      protected void checkContentSequence(StaticContext env) throws XPathException
      Check statically whether the content of the element creates attributes or namespaces after creating any child nodes
      Specified by:
      checkContentSequence in class ParentNodeConstructor
      Parameters:
      env - the static context
      Throws:
      XPathException
    • getElementName

      public abstract NodeName getElementName(XPathContext context, NodeInfo copiedNode) throws XPathException
      Determine (at run-time) the name code of the element being constructed
      Parameters:
      context - the XPath dynamic evaluation context
      copiedNode - for the benefit of xsl:copy, the node being copied; otherwise null
      Returns:
      the integer name code representing the element name
      Throws:
      XPathException - if a failure occurs
    • getNewBaseURI

      protected abstract String getNewBaseURI(XPathContext context, NodeInfo copiedNode)
      Get the base URI for the element being constructed
      Parameters:
      context - the XPath dynamic evaluation context
      copiedNode - the node being copied (for xsl:copy), otherwise null
      Returns:
      the base URI of the constructed element
    • outputNamespaceNodes

      protected abstract void outputNamespaceNodes(XPathContext context, Receiver receiver, NodeName nameCode, NodeInfo copiedNode) throws XPathException
      Callback to output namespace nodes for the new element. This method is responsible for ensuring that a namespace node is always generated for the namespace of the element name itself.
      Parameters:
      context - The execution context
      receiver - the Receiver where the namespace nodes are to be written
      nameCode - the name code of the element being created
      copiedNode - the node being copied (for xsl:copy) or null otherwise
      Throws:
      XPathException - if a dynamic error occurs
    • getActiveNamespaces

      public NamespaceBinding[] getActiveNamespaces() throws XPathException
      Callback to get a list of the intrinsic namespaces that need to be generated for the element.
      Returns:
      the set of namespace bindings.
      Throws:
      XPathException - if an error occurs
    • getImplementationMethod

      public int getImplementationMethod()
      An implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process(). This method indicates which of these methods is prefered. For instructions this is the process() method.
      Overrides:
      getImplementationMethod in class Instruction
      Returns:
      the implementation method, for example Expression.ITERATE_METHOD or Expression.EVALUATE_METHOD or Expression.PROCESS_METHOD
    • iterateEvents

      public EventIterator iterateEvents(XPathContext context) throws XPathException
      Description copied from class: Expression
      Deliver the result of the expression as a sequence of events.

      The events (of class PullEvent) are either complete items, or one of startElement, endElement, startDocument, or endDocument, known as semi-nodes. The stream of events may also include a nested EventIterator. If a start-end pair exists in the sequence, then the events between this pair represent the content of the document or element. The content sequence will have been processed to the extent that any attribute and namespace nodes in the content sequence will have been merged into the startElement event. Namespace fixup will have been performed: that is, unique prefixes will have been allocated to element and attribute nodes, and all namespaces will be declared by means of a namespace node in the startElement event or in an outer startElement forming part of the sequence. However, duplicate namespaces may appear in the sequence.

      The content of an element or document may include adjacent or zero-length text nodes, atomic values, and nodes represented as nodes rather than broken down into events.

      Overrides:
      iterateEvents in class Expression
      Parameters:
      context - The dynamic evaluation context
      Returns:
      the result of the expression as an iterator over a sequence of PullEvent objects
      Throws:
      XPathException - if a dynamic error occurs during expression evaluation
    • iterateEvents

      protected EventIterator iterateEvents(XPathContext context, NodeInfo copiedNode) throws XPathException
      Throws:
      XPathException
    • processLeavingTail

      public TailCall processLeavingTail(XPathContext context) throws XPathException
      Evaluate the instruction to produce a new element node. This method is typically used when there is a parent element or document in a result tree, to which the new element is added.
      Specified by:
      processLeavingTail in interface TailCallReturner
      Specified by:
      processLeavingTail in class Instruction
      Parameters:
      context - XPath dynamic evaluation context
      Returns:
      null (this instruction never returns a tail call)
      Throws:
      XPathException
    • processLeavingTail

      protected final TailCall processLeavingTail(XPathContext context, NodeInfo copiedNode) throws XPathException
      Evaluate the instruction to produce a new element node. This method is typically used when there is a parent element or document in a result tree, to which the new element is added.
      Parameters:
      context - XPath dynamic evaluation context
      copiedNode - null except in the case of xsl:copy, when it is the node being copied; otherwise null
      Returns:
      null (this instruction never returns a tail call)
      Throws:
      XPathException - if a dynamic error occurs
    • processLeft

      public void processLeft(Stack<XPathContext> contextStack, Stack<Object> state) throws XPathException
      In streaming mode, process the first half of the instruction (to start a new document or element)
      Parameters:
      contextStack - the dynamic evaluation context
      state - a stack on which the instruction can save state information for use during the corresponding
      Throws:
      XPathException - if a dynamic error occurs
    • processLeft

      protected final void processLeft(Stack<XPathContext> contextStack, Stack<Object> state, NodeInfo copiedNode) throws XPathException
      In streaming mode, process the first half of the instruction (to start a new document or element)
      Parameters:
      contextStack - the dynamic evaluation context
      state - a stack on which the instruction can save state information for use during the corresponding
      copiedNode - for the benefit of xsl:copy, the node being copied; otherwise null
      Throws:
      XPathException - if a dynamic error occurs
    • processRight

      public void processRight(Stack<XPathContext> contextStack, Stack<Object> state) throws XPathException
      In streaming mode, proecss the right half of the instruction (to end a new document or element)
      Parameters:
      contextStack - the stack of XPath context objects for the current execution state
      state - a stack on which the instruction can save state information for use during the corresponding
      Throws:
      XPathException - if a dynamic error occurs
    • evaluateItem

      public Item evaluateItem(XPathContext context) throws XPathException
      Evaluate the constructor, returning the constructed element node. If lazy construction mode is in effect, then an UnconstructedParent object is returned instead.
      Overrides:
      evaluateItem in class Instruction
      Parameters:
      context - The context in which the expression is to be evaluated
      Returns:
      the node or atomic value that results from evaluating the expression; or null to indicate that the result is an empty sequence
      Throws:
      XPathException - if any dynamic error occurs evaluating the expression