net.sf.saxon.sxpath
Class IndependentContext

java.lang.Object
  net.sf.saxon.sxpath.AbstractStaticContext
      net.sf.saxon.sxpath.IndependentContext

All Implemented Interfaces:

Serializable, SourceLocator, Container, StaticContext, NamespaceResolver, 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.

See Also:

Serialized Form

Constructor Summary

IndependentContext()

IndependentContext(Configuration config)
Create an IndependentContext using a specific Configuration

Method Summary

VariableReference	bindVariable(int fingerprint) 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(QNameValue qname) Declare a variable.
Set	getImportedSchemaNamespaces() Get the set of imported schemas
NamespaceResolver	getNamespaceResolver() Get a namespace resolver to resolve the namespaces declared in this static context.
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) Determine whether a Schema for a given target namespace has been imported.
void	issueWarning(String s, SourceLocator locator) Issue a compile-time warning.
Iterator	iteratePrefixes() Get an iterator over all the prefixes declared in this namespace context.
void	setImportedSchemaNamespaces(Set 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

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

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface net.sf.saxon.sxpath.XPathStaticContext

getExecutable, setDefaultElementNamespace

Methods inherited from interface net.sf.saxon.expr.StaticContext

getBaseURI, getCollation, getConfiguration, getDefaultCollationName, getDefaultElementNamespace, getDefaultFunctionNamespace, getFunctionLibrary, getLineNumber, getLocationMap, getNamePool, getSystemId, isAllowedBuiltInType, isInBackwardsCompatibleMode, makeEarlyEvaluationContext

Methods inherited from interface net.sf.saxon.expr.Container

getHostLanguage, getLocationProvider, replaceSubExpression

Methods inherited from interface javax.xml.transform.SourceLocator

getColumnNumber, getLineNumber, getPublicId, getSystemId

Constructor Detail

IndependentContext

public IndependentContext()

IndependentContext

public IndependentContext(Configuration config)

Create an IndependentContext using a specific Configuration

Method Detail

copy

public IndependentContext copy()

Create a copy of this IndependentContext. All aspects of the context are copied except for declared variables.

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.

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

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

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.

getSlotNumber

public int getSlotNumber(QNameValue qname)

Get the slot number allocated to a particular variable

Returns:

the slot number, or -1 if the variable has not been declared

issueWarning

public void issueWarning(String s,
                         SourceLocator locator)

Issue a compile-time warning. This method is used during XPath expression compilation to output warning conditions. The default implementation writes the message to System.err. To change the destination of messages, create a subclass of StandaloneContext that overrides this method.

Specified by:

issueWarning in interface StaticContext

Overrides:

issueWarning in class AbstractStaticContext

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

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 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.

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

bindVariable

public VariableReference bindVariable(int fingerprint)
                               throws StaticError

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:

fingerprint - the name of the variable

Returns:

a VariableReference representing the variable reference, suitably initialized to refer to the corresponding variable declaration

Throws:

StaticError

getStackFrameMap

public SlotManager getStackFrameMap()

Get a Stack Frame Map containing definitions of all the declared variables. This must be 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.

isImportedSchema

public boolean isImportedSchema(String namespace)

Description copied from interface: StaticContext

Determine 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

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

setImportedSchemaNamespaces

public void setImportedSchemaNamespaces(Set namespaces)