net.sf.saxon.xpath
Class StandaloneContext

java.lang.Object
  net.sf.saxon.xpath.StandaloneContext

All Implemented Interfaces:

NamespaceResolver, StaticContext

public class StandaloneContext

extends java.lang.Object

implements StaticContext, NamespaceResolver

A StandaloneContext provides a context for parsing an XPath expression in a context other than a stylesheet. In particular, it is used to support the JAXP 1.3 XPath API. This API does not actually expose the StaticContext object directly; rather, the static context (namespaces, variables, and functions) is manipulated through the XPath object, implemented in Saxon by the XPathEvaluator

Constructor Summary

StandaloneContext()
Create a StandaloneContext using the default Configuration and NamePool

StandaloneContext(Configuration config)
Create a StandaloneContext using a specific Configuration.

StandaloneContext(NodeInfo node)
Create a StandaloneContext using a specific Node.

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).
void	declareCollation(java.lang.String name, java.util.Comparator comparator, boolean isDefault) Declare a named collation
void	declareNamespace(java.lang.String prefix, java.lang.String uri) Declare a namespace whose prefix can be used in expressions.
Variable	declareVariable(java.lang.String qname, java.lang.Object initialValue) Declare a variable.
java.lang.String	getBaseURI() Get the Base URI of the stylesheet element, for resolving any relative URI's used in the expression.
java.util.Comparator	getCollation(java.lang.String name) Get a named collation.
Configuration	getConfiguration() Get the system configuration
java.lang.String	getDefaultCollationName() Get the name of the default collation.
short	getDefaultElementNamespace() Get the default XPath namespace, as a namespace code that can be looked up in the NamePool
java.lang.String	getDefaultFunctionNamespace() Get the default function namespace
FunctionLibrary	getFunctionLibrary() Get the function library containing all the in-scope functions available in this static context
java.util.Set	getImportedSchemaNamespaces() Get the set of imported schemas
int	getLineNumber() Get the line number of the expression within that container.
LocationMap	getLocationMap() Get the location map.
NamePool	getNamePool() Get the NamePool used for compiling expressions
javax.xml.namespace.NamespaceContext	getNamespaceContext() Get the NamespaceContext that was set using setNamespaceContext(javax.xml.namespace.NamespaceContext)
NamespaceResolver	getNamespaceResolver() Get a namespace resolver to resolve the namespaces declared in this static context.
SlotManager	getStackFrameMap() Get the stack frame map containing the slot number allocations for the variables declared in this static context
java.lang.String	getSystemId() Get the system ID of the container of the expression.
java.lang.String	getURIForPrefix(java.lang.String prefix) Get the URI for a prefix, using the declared namespaces as the context for namespace resolution.
java.lang.String	getURIForPrefix(java.lang.String prefix, boolean useDefault) Get the namespace URI corresponding to a given prefix.
javax.xml.xpath.XPathFunctionResolver	getXPathFunctionResolver()
javax.xml.xpath.XPathVariableResolver	getXPathVariableResolver() Get the XPathVariableResolver
void	importSchema(javax.xml.transform.Source source) Import a schema.
boolean	isAllowedBuiltInType(AtomicType type) Determine whether a built-in type is available in this context.
boolean	isImportedSchema(java.lang.String namespace) Determine whether a Schema for a given target namespace has been imported.
boolean	isInBackwardsCompatibleMode() Determine whether Backwards Compatible Mode is used
void	issueWarning(java.lang.String s, javax.xml.transform.SourceLocator locator) Issue a compile-time warning.
java.util.Iterator	iteratePrefixes() Get an iterator over all the prefixes declared in this namespace context.
XPathContext	makeEarlyEvaluationContext() Construct a dynamic context for early evaluation of constant subexpressions
void	setBackwardsCompatibilityMode(boolean backwardsCompatible) Set XPath 1.0 backwards compatibility mode
void	setBaseURI(java.lang.String baseURI) Set the base URI in the static context
void	setDefaultElementNamespace(java.lang.String uri) Set the default namespace for element and type names
void	setDefaultFunctionNamespace(java.lang.String uri) Set the default function namespace
void	setFunctionLibrary(FunctionLibrary lib) Set the function library to be used
void	setLocationMap(LocationMap locationMap)
void	setNamespaceContext(javax.xml.namespace.NamespaceContext context) Supply the NamespaceContext used to resolve namespaces.
void	setNamespaces(NodeInfo node) Set all the declared namespaces to be the namespaces that are in-scope for a given node.
void	setXPathFunctionResolver(javax.xml.xpath.XPathFunctionResolver xPathFunctionResolver)
void	setXPathVariableResolver(javax.xml.xpath.XPathVariableResolver resolver) Set an XPathVariableResolver.

Methods inherited from class java.lang.Object

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

Constructor Detail

StandaloneContext

public StandaloneContext()

Create a StandaloneContext using the default Configuration and NamePool

StandaloneContext

public StandaloneContext(Configuration config)

Create a StandaloneContext using a specific Configuration.

Parameters:

config - the Configuration. For schema-aware XPath expressions, this must be a SchemaAwareConfiguration.

StandaloneContext

public StandaloneContext(NodeInfo node)

Create a StandaloneContext using a specific Node. This node is used to initialize the NamePool and also to establish the initial set of in-scope namespaces.

Method Detail

getConfiguration

public Configuration getConfiguration()

Get the system configuration

Specified by:

getConfiguration in interface StaticContext

makeEarlyEvaluationContext

public XPathContext makeEarlyEvaluationContext()

Construct a dynamic context for early evaluation of constant subexpressions

Specified by:

makeEarlyEvaluationContext in interface StaticContext

getLocationMap

public LocationMap getLocationMap()

Description copied from interface: StaticContext

Get the location map. This is a mapping from short location ids held with each expression or subexpression, to a fully-resolved location in a source stylesheet or query.

Specified by:

getLocationMap in interface StaticContext

setLocationMap

public void setLocationMap(LocationMap locationMap)

declareNamespace

public void declareNamespace(java.lang.String prefix,
                             java.lang.String uri)

Declare a namespace whose prefix can be used in expressions. Namespaces may either be pre-declared (the traditional Saxon interface), or they may be resolved on demand using a supplied NamespaceContext. When a prefix has to be resolved, the parser looks first in the pre-declared namespaces, then in the supplied NamespaceContext object.

Parameters:

prefix - The namespace prefix. Must not be null. Must not be the empty string ("") - unqualified names in an XPath expression always refer to the null namespace.

uri - The namespace URI. Must not be null.

setNamespaceContext

public void setNamespaceContext(javax.xml.namespace.NamespaceContext context)

Supply the NamespaceContext used to resolve namespaces. This supplements namespaces that have been explicitly declared using declareNamespace(java.lang.String, java.lang.String) or that have been implicitly declared using setNamespaces(net.sf.saxon.om.NodeInfo)

getNamespaceContext

public javax.xml.namespace.NamespaceContext getNamespaceContext()

Get the NamespaceContext that was set using setNamespaceContext(javax.xml.namespace.NamespaceContext)

clearNamespaces

public void clearNamespaces()

Clear all the declared namespaces, except for the standard ones (xml, xslt, saxon, xdt). This doesn't clear the namespace context set using setNamespaceContext(javax.xml.namespace.NamespaceContext)

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="")

setNamespaces

public void setNamespaces(NodeInfo node)

Set all the declared namespaces to be the namespaces that are in-scope for a given node. In addition, the standard namespaces (xml, xslt, saxon) are declared.

Parameters:

node - The node whose in-scope namespaces are to be used as the context namespaces. Note that this will have no effect unless this node is an element.

setBaseURI

public void setBaseURI(java.lang.String baseURI)

Set the base URI in the static context

declareCollation

public void declareCollation(java.lang.String name,
                             java.util.Comparator comparator,
                             boolean isDefault)

Declare a named collation

Parameters:

name - The name of the collation (technically, a URI)

comparator - The Java Comparator used to implement the collating sequence

isDefault - True if this is to be used as the default collation

getStackFrameMap

public SlotManager getStackFrameMap()

Get the stack frame map containing the slot number allocations for the variables declared in this static context

declareVariable

public Variable declareVariable(java.lang.String qname,
                                java.lang.Object initialValue)
                         throws XPathException

Declare a variable. A variable may be declared before an expression referring to it is compiled. Alternatively, a JAXP XPathVariableResolver may be supplied to perform the resolution. A variable that has been explicitly declared is used in preference.

Parameters:

qname - Lexical QName identifying the variable. The namespace prefix, if any, must have been declared before this method is called, or must be resolvable using the namespace context.

initialValue - The initial value of the variable. A Java object that can be converted to an XPath value.

Throws:

XPathException

setXPathVariableResolver

public void setXPathVariableResolver(javax.xml.xpath.XPathVariableResolver resolver)

Set an XPathVariableResolver. This is used to resolve variable references if no variable has been explicitly declared.

Parameters:

resolver - A JAXP 1.3 XPathVariableResolver

getXPathVariableResolver

public javax.xml.xpath.XPathVariableResolver getXPathVariableResolver()

Get the XPathVariableResolver

setXPathFunctionResolver

public void setXPathFunctionResolver(javax.xml.xpath.XPathFunctionResolver xPathFunctionResolver)

getXPathFunctionResolver

public javax.xml.xpath.XPathFunctionResolver getXPathFunctionResolver()

getNamePool

public NamePool getNamePool()

Get the NamePool used for compiling expressions

Specified by:

getNamePool in interface StaticContext

issueWarning

public void issueWarning(java.lang.String s,
                         javax.xml.transform.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

getSystemId

public java.lang.String getSystemId()

Get the system ID of the container of the expression. Used to construct error messages.

Specified by:

getSystemId in interface StaticContext

Returns:

"" always

getBaseURI

public java.lang.String getBaseURI()

Get the Base URI of the stylesheet element, for resolving any relative URI's used in the expression. Used by the document() function, resolve-uri(), etc.

Specified by:

getBaseURI in interface StaticContext

Returns:

"" if no base URI has been set

getLineNumber

public int getLineNumber()

Get the line number of the expression within that container. Used to construct error messages.

Specified by:

getLineNumber in interface StaticContext

Returns:

-1 always

getURIForPrefix

public java.lang.String getURIForPrefix(java.lang.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 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. This method first searches any namespaces declared using declareNamespace(String, String), and then searches any namespace context supplied using setNamespaceContext(javax.xml.namespace.NamespaceContext).

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 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. The iterator only covers namespaces explicitly declared using declareNamespace(String, String); it does not include namespaces declared using setNamespaceContext(javax.xml.namespace.NamespaceContext), because the JAXP NamespaceContext class provides no way to discover all the namespaces available.

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.

If the variable has been explicitly declared using declareVariable(String, Object), that value is used; otherwise if a variable resolved has been supplied using setXPathVariableResolver(javax.xml.xpath.XPathVariableResolver) then that is used.

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 - If no variable with the given name is found, or if the value supplied for the variable cannot be converted to an XPath value.

getFunctionLibrary

public FunctionLibrary getFunctionLibrary()

Get the function library containing all the in-scope functions available in this static context

Specified by:

getFunctionLibrary in interface StaticContext

setFunctionLibrary

public void setFunctionLibrary(FunctionLibrary lib)

Set the function library to be used

getCollation

public java.util.Comparator getCollation(java.lang.String name)

Get a named collation.

Specified by:

getCollation in interface StaticContext

Parameters:

name - The name of the required collation. Supply null to get the default collation.

Returns:

the collation identified by the given name, as set previously using declareCollation. Return null if no collation with this name is found.

getDefaultCollationName

public java.lang.String getDefaultCollationName()

Get the name of the default collation.

Specified by:

getDefaultCollationName in interface StaticContext

Returns:

the name of the default collation; or the name of the codepoint collation if no default collation has been defined

setDefaultElementNamespace

public void setDefaultElementNamespace(java.lang.String uri)

Set the default namespace for element and type names

getDefaultElementNamespace

public short getDefaultElementNamespace()

Get the default XPath namespace, as a namespace code that can be looked up in the NamePool

Specified by:

getDefaultElementNamespace in interface StaticContext

setDefaultFunctionNamespace

public void setDefaultFunctionNamespace(java.lang.String uri)

Set the default function namespace

getDefaultFunctionNamespace

public java.lang.String getDefaultFunctionNamespace()

Get the default function namespace

Specified by:

getDefaultFunctionNamespace in interface StaticContext

setBackwardsCompatibilityMode

public void setBackwardsCompatibilityMode(boolean backwardsCompatible)

Set XPath 1.0 backwards compatibility mode

Parameters:

backwardsCompatible - if true, expressions will be evaluated with XPath 1.0 compatibility mode set to true.

isInBackwardsCompatibleMode

public boolean isInBackwardsCompatibleMode()

Determine whether Backwards Compatible Mode is used

Specified by:

isInBackwardsCompatibleMode in interface StaticContext

Returns:

false; XPath 1.0 compatibility mode is not supported in the standalone XPath API

importSchema

public void importSchema(javax.xml.transform.Source source)
                  throws SchemaException

Import a schema. This is possible only if the schema-aware version of Saxon is being used, and if the Configuration is a SchemaAwareConfiguration. Having imported a schema, the types defined in that schema become part of the static context.

Parameters:

source - A Source object identifying the schema document to be loaded

Throws:

SchemaException - if the schema contained in this document is invalid

java.lang.UnsupportedOperationException - if the configuration is not schema-aware

isImportedSchema

public boolean isImportedSchema(java.lang.String namespace)

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

Returns:

This implementation always returns false: the standalone XPath API does not support schema-aware processing.

getImportedSchemaNamespaces

public java.util.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

isAllowedBuiltInType

public boolean isAllowedBuiltInType(AtomicType type)

Determine whether a built-in type is available in this context. This method caters for differences between host languages as to which set of types are built in.

Specified by:

isAllowedBuiltInType in interface StaticContext

Parameters:

type - the supposedly built-in type. This will always be a type in the XS or XDT namespace.

Returns:

true if this type can be used in this static context