Package net.sf.saxon.sxpath

Class IndependentContext

java.lang.Object
net.sf.saxon.sxpath.AbstractStaticContext
net.sf.saxon.sxpath.IndependentContext
All Implemented Interfaces:
StaticContext, NamespaceResolver
Direct Known Subclasses:
SchemaElement.XPathStaticContext
public class IndependentContext extends AbstractStaticContext implements NamespaceResolver
An IndependentContext provides a context for parsing an XPath expression appearing in a context other than a stylesheet.

This class is used in a number of places where freestanding XPath expressions occur. These include the native Saxon XPath API, the .NET XPath API, XPath expressions used in XML Schema identity constraints, and XPath expressions supplied to saxon:evaluate(). It is not used by the JAXP XPath API (though it shares code with that API through the common superclass AbstractStaticContext).

This class currently provides no mechanism for binding user-defined functions.

  • Field Details

  • Constructor Details

    • IndependentContext

      public IndependentContext()
      Create an IndependentContext along with a new (non-schema-aware) Saxon Configuration

    • IndependentContext

      public IndependentContext(Configuration config)
      Create an IndependentContext using a specific Configuration
      Parameters:
      config - the Saxon configuration to be used

    • IndependentContext

      public IndependentContext(Configuration config, int version)
      Create an IndependentContext using a specific Configuration
      Parameters:
      config - the Saxon configuration to be used
      version - the XPath language version (31 = XPath 3.1, 40 = XPath 4.0)

    • IndependentContext

      public IndependentContext(IndependentContext ic)
      Create a IndependentContext as a copy of another IndependentContext
      Parameters:
      ic - the IndependentContext to be copied

  • Method Details

    • makeRetainedStaticContext

      public RetainedStaticContext makeRetainedStaticContext()
      Construct a RetainedStaticContext, which extracts information from this StaticContext to provide the subset of static context information that is potentially needed during expression evaluation. This implementation returns the same RetainedStaticContext object each time, which relies on the information in the static context being effectively immutable while the IndependentContext object remains in use.
      Specified by:
      makeRetainedStaticContext in interface StaticContext
      Overrides:
      makeRetainedStaticContext in class AbstractStaticContext
      Returns:
      a RetainedStaticContext object: either a newly created one, or one that is reused from a previous invocation.

    • declareNamespace

      public void declareNamespace(String prefix, NamespaceUri uri)
      Declare a namespace whose prefix can be used in expressions
      Parameters:
      prefix - The namespace prefix. Must not be null. Supplying "" sets the default element namespace.
      uri - The namespace URI. Must not be null.

    • setDefaultElementNamespace

      public void setDefaultElementNamespace(NamespaceUri uri)
      Set the default namespace for elements and types
      Overrides:
      setDefaultElementNamespace in class AbstractStaticContext
      Parameters:
      uri - the namespace to be used for unprefixed element and type names. The value "" (or NamespaceConstant.NULL) represents the non-namespace

    • clearNamespaces

      public void clearNamespaces()
      Clear all the declared namespaces, except for the standard ones (xml, xsl, saxon). This also resets the default element namespace to the "null" namespace

    • clearAllNamespaces

      public void clearAllNamespaces()
      Clear all the declared namespaces, including the standard ones (xml, xslt, saxon). Leave only the XML namespace and the default namespace (xmlns=""). This also resets the default element namespace to the "null" namespace.

    • setNamespaces

      public void setNamespaces(NodeInfo node)
      Declares all the namespaces that are in-scope for a supplied node, removing all previous namespace declarations. In addition, the standard namespaces (xml, xslt, saxon) are declared. This method also sets the default element namespace to be the same as the default namespace for this node.
      Parameters:
      node - The node whose in-scope namespaces are to be used as the context namespaces. If the node is an attribute, text node, etc, then the namespaces of its parent element are used.

    • setNamespaceResolver

      public void setNamespaceResolver(NamespaceResolver resolver)
      Set an external namespace resolver. If this is set, then all resolution of namespace prefixes is delegated to the external namespace resolver, and namespaces declared individually on this IndependentContext object are ignored.
      Parameters:
      resolver - the external NamespaceResolver

    • setAllowUndeclaredVariables

      public void setAllowUndeclaredVariables(boolean allow)
      Say whether undeclared variables are allowed. By default, they are not allowed. When undeclared variables are allowed, it is not necessary to predeclare the variables that may be used in the XPath expression; instead, a variable is automatically declared when a reference to the variable is encountered within the expression.
      Parameters:
      allow - true if undeclared variables are allowed, false if they are not allowed.
      Since:
      9.2

    • isAllowUndeclaredVariables

      public boolean isAllowUndeclaredVariables()
      Ask whether undeclared variables are allowed. By default, they are not allowed. When undeclared variables are allowed, it is not necessary to predeclare the variables that may be used in the XPath expression; instead, a variable is automatically declared when a reference to the variable is encountered within the expression.
      Returns:
      true if undeclared variables are allowed, false if they are not allowed.
      Since:
      9.2

    • declareVariable

      public XPathVariable declareVariable(QNameValue qname)
      Declare a variable. A variable must be declared before an expression referring to it is compiled. The initial value of the variable will be the empty sequence
      Parameters:
      qname - The name of the variable
      Returns:
      an XPathVariable object representing information about the variable that has been declared.

    • declareVariable

      public XPathVariable declareVariable(NamespaceUri namespaceURI, String localName)
      Declare a variable. A variable must be declared before an expression referring to it is compiled. The initial value of the variable will be the empty sequence
      Parameters:
      namespaceURI - The namespace URI of the name of the variable. Supply "" to represent names in no namespace (null is also accepted)
      localName - The local part of the name of the variable (an NCName)
      Returns:
      an XPathVariable object representing information about the variable that has been declared.

    • declareVariable

      public XPathVariable declareVariable(StructuredQName qName)
      Declare a variable. A variable must be declared before an expression referring to it is compiled. The initial value of the variable will be the empty sequence
      Parameters:
      qName - the name of the variable.
      Returns:
      an XPathVariable object representing information about the variable that has been declared.
      Since:
      9.2

    • getExternalVariables

      public Iterable<XPathVariable> getExternalVariables()
      Get an iterator over all the variables that have been declared, either explicitly by an application call on declareVariable(), or implicitly if the option allowUndeclaredVariables is set.
      Returns:
      an iterator; the objects returned by this iterator will be instances of XPathVariable
      Since:
      9.2

    • getExternalVariable

      public XPathVariable getExternalVariable(StructuredQName qName)
      Get the declared variable with a given name, if there is one
      Parameters:
      qName - the name of the required variable
      Returns:
      the explicitly or implicitly declared variable with this name if it exists, or null otherwise
      Since:
      9.2

    • getSlotNumber

      public int getSlotNumber(QNameValue qname)
      Get the slot number allocated to a particular variable
      Parameters:
      qname - the name of the variable
      Returns:
      the slot number, or -1 if the variable has not been declared

    • getNamespaceResolver

      public NamespaceResolver getNamespaceResolver()
      Description copied from interface: StaticContext
      Get a namespace resolver to resolve the namespaces declared in this static context.
      Specified by:
      getNamespaceResolver in interface StaticContext
      Returns:
      a namespace resolver.

    • getURIForPrefix

      public NamespaceUri getURIForPrefix(String prefix, boolean useDefault)
      Get the namespace URI corresponding to a given prefix. Return null if the prefix is not in scope.
      Specified by:
      getURIForPrefix in interface NamespaceResolver
      Parameters:
      prefix - the namespace prefix
      useDefault - true if the default namespace is to be used when the prefix is ""
      Returns:
      the uri for the namespace, or null if the prefix is not in scope. Return "" if the prefix maps to the null namespace.

    • iteratePrefixes

      public Iterator<String> iteratePrefixes()
      Get an iterator over all the prefixes declared in this namespace context. This will include the default namespace (prefix="") and the XML namespace where appropriate
      Specified by:
      iteratePrefixes in interface NamespaceResolver
      Returns:
      an iterator over all the prefixes for which a namespace binding exists, including the zero-length string to represent the null/absent prefix if it is bound

    • bindVariable

      public Expression bindVariable(StructuredQName qName) throws XPathException
      Bind a variable used in an XPath Expression to the XSLVariable element in which it is declared. This method is provided for use by the XPath parser, and it should not be called by the user of the API, or overridden, unless variables are to be declared using a mechanism other than the declareVariable method of this class.
      Specified by:
      bindVariable in interface StaticContext
      Parameters:
      qName - the name of the variable
      Returns:
      the resulting variable reference
      Throws:
      XPathException - if the variable cannot be bound (has not been declared)

    • getStackFrameMap

      public SlotManager getStackFrameMap()
      Get a Stack Frame Map containing definitions of all the declared variables. This will return a newly created object that the caller is free to modify by adding additional variables, without affecting the static context itself.

    • getDeclaredVariables

      public Collection<XPathVariable> getDeclaredVariables()

    • setImportedSchema

      public void setImportedSchema(Schema schema)
      Add an imported schema to the static context

    • getImportedSchema

      public Schema getImportedSchema()
      Get the imported schema for this static context, if any
      Specified by:
      getImportedSchema in interface StaticContext
      Overrides:
      getImportedSchema in class AbstractStaticContext
      Returns:
      the imported schema, or the MinimalSchema if no schema has been imported

    • setRequiredContextItemType

      public void setRequiredContextItemType(ItemType type)
      Declare the static type of the context item. If this type is declared, and if a context item is supplied when the query is invoked, then the context item must conform to this type (no type conversion will take place to force it into this type).
      Parameters:
      type - the required type of the context item
      Since:
      9.3

    • setRequiredContextValueType

      public void setRequiredContextValueType(SequenceType type)
      Declare the static type of the context item. If this type is declared, and if a context value is supplied when the query is invoked, then the context value must conform to this type (no type conversion will take place to force it into this type).
      Parameters:
      type - the required type of the context item
      Since:
      13.0

    • getRequiredContextItemType

      public ItemType getRequiredContextItemType()
      Get the required type of the context item. If no type has been explicitly declared for the context item, an instance of AnyItemType (representing the type item()) is returned.
      Specified by:
      getRequiredContextItemType in interface StaticContext
      Overrides:
      getRequiredContextItemType in class AbstractStaticContext
      Returns:
      the required type of the context item
      Since:
      9.3

    • getRequiredContextValueType

      public SequenceType getRequiredContextValueType()
      Get the required type of the context item. If no type has been explicitly declared for the context item, an instance of AnyItemType (representing the type item()) is returned.
      Specified by:
      getRequiredContextValueType in interface StaticContext
      Overrides:
      getRequiredContextValueType in class AbstractStaticContext
      Returns:
      the required type of the context item
      Since:
      9.3

    • setOptimizerOptions

      public void setOptimizerOptions(OptimizerOptions options)
      Set the optimizer options to be used for compiling expressions that use this static context. By default the optimizer options set in the Configuration are used.
      Parameters:
      options - the optimizer options to be used

    • getOptimizerOptions

      public OptimizerOptions getOptimizerOptions()
      Get the optimizer options being used for compiling expressions that use this static context. By default the optimizer options set in the Configuration are used.
      Specified by:
      getOptimizerOptions in interface StaticContext
      Returns:
      the optimizer options being used

    • setExecutable

      public void setExecutable(Executable exec)

    • getExecutable

      public Executable getExecutable()

    • getColumnNumber

      public int getColumnNumber()

    • getPublicId

      public String getPublicId()

    • getLineNumber

      public int getLineNumber()

    • isContextItemParentless

      public boolean isContextItemParentless()
      Ask whether the context item is known to be parentless
      Returns:
      true if it is known that the context item for evaluating the expression will have no parent

    • setContextItemParentless

      public void setContextItemParentless(boolean parentless)
      Say whether the context item is known to be parentless. This is used for XSD Assertions; it allows a static warning if an XSD assertion attempts to look outside the element being validated.
      Parameters:
      parentless - true if it is known that the context item for evaluating the expression will have no parent