net.sf.saxon.sxpath

Class IndependentContext

Implemented Interfaces:
Container, Serializable, SourceLocator, Container, NamespaceResolver, SourceLocator, StaticContext, XPathStaticContext

public class IndependentContext
extends AbstractStaticContext
implements XPathStaticContext, NamespaceResolver, Serializable, Container

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.

Constructor Summary

IndependentContext()
Create an IndependentContext along with a new (non-schema-aware) Saxon Configuration
IndependentContext(Configuration config)
Create an IndependentContext using a specific Configuration

Method Summary

VariableReference
bindVariable(StructuredQName qName)
Bind a variable used in an XPath Expression to the XSLVariable element in which it is declared.
void
clearAllNamespaces()
Clear all the declared namespaces, including the standard ones (xml, xslt, saxon).
void
clearNamespaces()
Clear all the declared namespaces, except for the standard ones (xml, xslt, saxon, xdt).
IndependentContext
copy()
Create a copy of this IndependentContext.
void
declareNamespace(String prefix, String uri)
Declare a namespace whose prefix can be used in expressions
XPathVariable
declareVariable(String namespaceURI, String localName)
Declare a variable.
XPathVariable
declareVariable(QNameValue qname)
Declare a variable.
Set
getImportedSchemaNamespaces()
Get the set of imported schemas
NamespaceResolver
getNamespaceResolver()
int
getSlotNumber(QNameValue qname)
Get the slot number allocated to a particular variable
SlotManager
getStackFrameMap()
Get a Stack Frame Map containing definitions of all the declared variables.
String
getURIForPrefix(String prefix)
Get the URI for a prefix, using the declared namespaces as the context for namespace resolution.
String
getURIForPrefix(String prefix, boolean useDefault)
Get the namespace URI corresponding to a given prefix.
boolean
isImportedSchema(String namespace)
Iterator
iteratePrefixes()
Get an iterator over all the prefixes declared in this namespace context.
void
setImportedSchemaNamespaces(Set namespaces)
Register the set of imported schema namespaces
void
setNamespaceResolver(NamespaceResolver resolver)
Set an external namespace resolver.
void
setNamespaces(NodeInfo node)
Declares all the namespaces that are in-scope for a given node, removing all previous namespace declarations.

Methods inherited from class net.sf.saxon.sxpath.AbstractStaticContext

addFunctionLibrary, declareCollation, getBaseURI, getCollation, getColumnNumber, getConfiguration, getDefaultCollationName, getDefaultElementNamespace, getDefaultFunctionNamespace, getExecutable, getFunctionLibrary, getHostLanguage, getLineNumber, getLocationMap, getLocationProvider, getNamePool, getPublicId, getSystemId, isAllowedBuiltInType, isInBackwardsCompatibleMode, issueWarning, makeEarlyEvaluationContext, replaceSubExpression, setBackwardsCompatibilityMode, setBaseURI, setConfiguration, setDefaultElementNamespace, setDefaultFunctionLibrary, setDefaultFunctionNamespace, setFunctionLibrary, setLocationMap

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

Method Details

bindVariable

public VariableReference 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

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.

clearNamespaces

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

copy

public IndependentContext copy()
Create a copy of this IndependentContext. All aspects of the context are copied except for declared variables.
Returns:
the new copy

declareNamespace

public void declareNamespace(String prefix,
                             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.

declareVariable

public XPathVariable declareVariable(String 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
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(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.

getImportedSchemaNamespaces

public Set 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

getNamespaceResolver

public NamespaceResolver getNamespaceResolver()
Specified by:
getNamespaceResolver in interface StaticContext

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

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

getURIForPrefix

public String getURIForPrefix(String prefix)
            throws XPathException
Get the URI for a prefix, using the declared namespaces as the context for namespace resolution. The default namespace is NOT used when the prefix is empty. This method is provided for use by the XPath parser.
Specified by:
getURIForPrefix in interface StaticContext
Parameters:
prefix - The prefix
Throws:
XPathException - if the prefix is not declared

getURIForPrefix

public String 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.

isImportedSchema

public boolean isImportedSchema(String namespace)
Specified by:
isImportedSchema in interface StaticContext

iteratePrefixes

public Iterator 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

setImportedSchemaNamespaces

public void setImportedSchemaNamespaces(Set namespaces)
Register the set of imported schema namespaces
Parameters:
namespaces - the set of namespaces for which schema components are available in the static context

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

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.