Package net.sf.saxon.sxpath

Class IndependentContext

  • All Implemented Interfaces:
    StaticContext, NamespaceResolver, XPathStaticContext
    Direct Known Subclasses:
    SchemaElement.XPathStaticContext
    public class IndependentContext
extends AbstractStaticContext
implements XPathStaticContext, 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 Detail

      • namespaces

        protected java.util.HashMap<java.lang.String,​java.lang.String> namespaces

      • requiredContextItemType

        protected ItemType requiredContextItemType

      • importedSchemaNamespaces

        protected java.util.Set<java.lang.String> importedSchemaNamespaces

      • autoDeclare

        protected boolean autoDeclare

      • parentlessContextItem

        protected boolean parentlessContextItem

    • Constructor Detail

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

    • Method Detail

      • 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​(java.lang.String prefix,
                             java.lang.String 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.

      • 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 given 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.
        Specified by:
        setNamespaceResolver in interface XPathStaticContext
        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
        Specified by:
        declareVariable in interface XPathStaticContext
        Parameters:
        qname - The name of the variable
        Returns:
        an XPathVariable object representing information about the variable that has been declared.

      • declareVariable

        public XPathVariable declareVariable​(java.lang.String namespaceURI,
                                     java.lang.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
        Specified by:
        declareVariable in interface XPathStaticContext
        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 java.lang.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

      • getURIForPrefix

        public java.lang.String getURIForPrefix​(java.lang.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 java.util.Iterator<java.lang.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.
        Specified by:
        getStackFrameMap in interface XPathStaticContext
        Returns:
        a SlotManager object holding details of the allocation of variables on the stack frame.

      • getDeclaredVariables

        public java.util.Collection<XPathVariable> getDeclaredVariables()

      • isImportedSchema

        public boolean isImportedSchema​(java.lang.String namespace)
        Description copied from interface: StaticContext
        Ask whether a Schema for a given target namespace has been imported. Note that the in-scope element declarations, attribute declarations and schema types are the types registered with the (schema-aware) configuration, provided that their namespace URI is registered in the static context as being an imported schema namespace. (A consequence of this is that within a Configuration, there can only be one schema for any given namespace, including the null namespace).
        Specified by:
        isImportedSchema in interface StaticContext
        Parameters:
        namespace - the target namespace in question
        Returns:
        true if the given namespace has been imported

      • getImportedSchemaNamespaces

        public java.util.Set<java.lang.String> getImportedSchemaNamespaces()
        Get the set of imported schemas
        Specified by:
        getImportedSchemaNamespaces in interface StaticContext
        Returns:
        a Set, the set of URIs representing the names of imported schemas

      • setImportedSchemaNamespaces

        public void setImportedSchemaNamespaces​(java.util.Set<java.lang.String> namespaces)
        Register the set of imported schema namespaces
        Parameters:
        namespaces - the set of namespaces for which schema components are available in the static context

      • 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

      • 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 java.lang.String getPublicId()

      • getLineNumber

        public int getLineNumber()

      • isContextItemParentless

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

      • setContextItemParentless

        public void setContextItemParentless​(boolean parentless)