Class GlobalVariable

java.lang.Object
net.sf.saxon.expr.instruct.GeneralVariable
net.sf.saxon.expr.instruct.GlobalVariable
All Implemented Interfaces:
Serializable, SourceLocator, LocationProvider, SaxonLocator, Binding, Container, InstructionInfo, Locator
Direct Known Subclasses:
GlobalParam

public class GlobalVariable extends GeneralVariable implements Container, InstructionInfo
A compiled global variable in a stylesheet or query.
See Also:
  • Constructor Details

    • GlobalVariable

      public GlobalVariable()
      Create a global variable
  • Method Details

    • getExecutable

      public Executable getExecutable()
      Get the executable containing this global variable
      Specified by:
      getExecutable in interface Container
      Overrides:
      getExecutable in class GeneralVariable
      Returns:
      the containing executable
    • setExecutable

      public void setExecutable(Executable executable)
      Set the containing executable
      Parameters:
      executable - the executable that contains this global variable
    • getLineNumber

      public int getLineNumber(long locationId)
      Get the line number within the document, entity or module containing a particular location
      Specified by:
      getLineNumber in interface LocationProvider
      Parameters:
      locationId - identifier of the location in question (as passed down the Receiver pipeline)
      Returns:
      the line number within the document, entity or module, or -1 if no information is available.
    • getColumnNumber

      public int getColumnNumber(long locationId)
      Get the column number within the document, entity, or module containing a particular location
      Specified by:
      getColumnNumber in interface LocationProvider
      Parameters:
      locationId - identifier of the location in question (as passed down the Receiver pipeline)
      Returns:
      the column number within the document, entity, or module, or -1 if this is not available
    • getConstructType

      public int getConstructType()
      Get the type of construct. This will either be the fingerprint of a standard XSLT instruction name (values in StandardNames: all less than 1024) or it will be a constant in class Location.
      Specified by:
      getConstructType in interface InstructionInfo
      Returns:
      an integer identifying the kind of construct
    • getObjectName

      public StructuredQName getObjectName()
      Get a name identifying the object of the expression, for example a function name, template name, variable name, key name, element name, etc. This is used only where the name is known statically.
      Specified by:
      getObjectName in interface InstructionInfo
      Returns:
      the QName of the object declared or manipulated by this instruction or expression
    • getProperty

      public Object getProperty(String name)
      Get the value of a particular property of the instruction. Properties of XSLT instructions are generally known by the name of the stylesheet attribute that defines them.
      Specified by:
      getProperty in interface InstructionInfo
      Parameters:
      name - The name of the required property
      Returns:
      The value of the requested property, or null if the property is not available
    • getProperties

      public Iterator<String> getProperties()
      Get an iterator over all the properties available. The values returned by the iterator will be of type String, and each string can be supplied as input to the getProperty() method to retrieve the value of the property. The iterator may return properties whose value is null.
      Specified by:
      getProperties in interface InstructionInfo
      Returns:
      an iterator over the properties.
    • getContainer

      public Container getContainer()
      Get the container in which this expression is located. This will usually be a top-level construct such as a function or global variable, and XSLT template, or an XQueryExpression. In the case of free-standing XPath expressions it will be the StaticContext object
      Overrides:
      getContainer in class GeneralVariable
      Returns:
      the expression's container
    • getHostLanguage

      public int getHostLanguage()
      Get the host language (XSLT, XQuery, XPath) used to implement the code in this container
      Specified by:
      getHostLanguage in interface Container
      Returns:
      typically Configuration.XSLT or Configuration.XQUERY
    • setIndexedVariable

      public void setIndexedVariable()
      Mark this as an indexed variable, to allow fast searching
    • isIndexedVariable

      public boolean isIndexedVariable()
      Ask whether this is an indexed variable
      Returns:
      true if this variable is indexed
    • getContainerGranularity

      public int getContainerGranularity()
      Get the granularity of the container.
      Specified by:
      getContainerGranularity in interface Container
      Returns:
      0 for a temporary container created during parsing; 1 for a container that operates at the level of an XPath expression; 2 for a container at the level of a global function or template
    • setContainsLocals

      public void setContainsLocals(SlotManager map)
      The expression that initializes a global variable may itself use local variables. In this case a stack frame needs to be allocated while evaluating the global variable
      Parameters:
      map - The stack frame map for local variables used while evaluating this global variable.
    • isGlobal

      public boolean isGlobal()
      Is this a global variable?
      Specified by:
      isGlobal in interface Binding
      Overrides:
      isGlobal in class GeneralVariable
      Returns:
      true (yes, it is a global variable)
    • lookForCycles

      public void lookForCycles(Stack<Container> referees, XQueryFunctionLibrary globalFunctionLibrary) throws XPathException
      Check for cycles in this variable definition
      Parameters:
      referees - the calls leading up to this one; it's an error if this variable is on the stack, because that means it calls itself directly or indirectly. The stack may contain variable definitions (GlobalVariable objects) and user-defined functions (UserFunction objects). It will never contain the same object more than once.
      globalFunctionLibrary - the library containing all global functions
      Throws:
      XPathException - if cycles are found
    • getSelectValue

      public ValueRepresentation getSelectValue(XPathContext context) throws XPathException
      Evaluate the variable. That is, get the value of the select expression if present or the content of the element otherwise, either as a tree or as a sequence
      Overrides:
      getSelectValue in class GeneralVariable
      Parameters:
      context - the XPath dynamic context
      Returns:
      the result of evaluating the variable
      Throws:
      XPathException - if evaluation of the select expression fails with a dynamic error
    • evaluateVariable

      public ValueRepresentation evaluateVariable(XPathContext context) throws XPathException
      Evaluate the variable
      Specified by:
      evaluateVariable in interface Binding
      Parameters:
      context - the XPath dynamic evaluation context
      Returns:
      the result of evaluating the variable
      Throws:
      XPathException - if an error occurs while evaluating the variable
    • actuallyEvaluate

      protected ValueRepresentation actuallyEvaluate(XPathContext context) throws XPathException
      Evaluate the global variable, and save its value for use in subsequent references.
      Parameters:
      context - the XPath dynamic context
      Returns:
      the value of the variable
      Throws:
      XPathException - if evaluation fails
    • setDependencies

      protected static void setDependencies(Bindery bindery, GlobalVariable var, XPathContext context) throws XPathException
      Get the variable that is immediately dependent on this one, and register the dependency, so that circularities can be detected across threads. This relies on the fact that when the initialiser for variable X contains a reference to variable Y, then when Y is evaluated, a stack frame will be found on the context stack representing the evaluation of X. We don't set a dependency from X to Y if the value of Y was already available in the Bindery; it's not needed, because in this case we know that evaluation of Y is unproblematic, and can't lead to any circularities.
      Parameters:
      bindery - the Bindery
      var - the global variable or parameter being evaluated
      context - the dynamic evaluation context
      Throws:
      XPathException