net.sf.saxon.sxpath
Class IndependentContext

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

All Implemented Interfaces:

Serializable, StaticContext, NamespaceResolver, XPathStaticContext

Direct Known Subclasses:

DedicatedStaticContext

public class IndependentContext
extends AbstractStaticContext
implements XPathStaticContext, NamespaceResolver, Serializable

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

Field Summary

protected boolean	autoDeclare
protected NamespaceResolver	externalResolver
protected Set	importedSchemaNamespaces
protected HashMap<String,String>	namespaces
protected ItemType	requiredContextItemType
protected HashMap<StructuredQName,XPathVariable>	variables

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

usingDefaultFunctionLibrary

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

Expression	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).
void	declareNamespace(String prefix, String uri) Declare a namespace whose prefix can be used in expressions
XPathVariable	declareVariable(QNameValue qname) Declare a variable.
XPathVariable	declareVariable(String namespaceURI, String localName) Declare a variable.
XPathVariable	declareVariable(StructuredQName qName) Declare a variable.
int	getContainerGranularity() Get the granularity of the container.
XPathVariable	getExternalVariable(StructuredQName qName) Get the declared variable with a given name, if there is one
Set<String>	getImportedSchemaNamespaces() Get the set of imported schemas
NamespaceResolver	getNamespaceResolver() Get a namespace resolver to resolve the namespaces declared in this static context.
ItemType	getRequiredContextItemType() Get the required type of the context item.
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	isAllowUndeclaredVariables() Ask whether undeclared variables are allowed.
boolean	isImportedSchema(String namespace) Ask whether a Schema for a given target namespace has been imported.
Iterator<XPathVariable>	iterateExternalVariables() 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.
Iterator	iteratePrefixes() Get an iterator over all the prefixes declared in this namespace context.
void	setAllowUndeclaredVariables(boolean allow) Say whether undeclared variables are allowed.
void	setDefaultElementNamespace(String uri) Set the default namespace for elements and types
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.
void	setRequiredContextItemType(ItemType type) Declare the static type of the context item.

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

addFunctionLibrary, declareCollation, getBaseURI, getCollation, getCollationMap, getColumnNumber, getConfiguration, getDecimalFormatManager, getDefaultCollationName, getDefaultElementNamespace, getDefaultFunctionNamespace, getFunctionLibrary, getHostLanguage, getLineNumber, getLocationMap, getLocationProvider, getNamePool, getPublicId, getSystemId, getXPathLanguageLevel, isAllowedBuiltInType, isInBackwardsCompatibleMode, isSchemaAware, issueWarning, makeEarlyEvaluationContext, setBackwardsCompatibilityMode, setBaseURI, setCollationMap, setConfiguration, setDecimalFormatManager, setDefaultFunctionLibrary, setDefaultFunctionNamespace, setFunctionLibrary, setLocationMap, setSchemaAware, setXPathLanguageLevel

Methods inherited from class java.lang.Object

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

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

getBaseURI, getCollation, getConfiguration, getDecimalFormatManager, getDefaultCollationName, getDefaultElementNamespace, getDefaultFunctionNamespace, getFunctionLibrary, getLineNumber, getLocationMap, getNamePool, getSystemId, getXPathLanguageLevel, isAllowedBuiltInType, isInBackwardsCompatibleMode, isSchemaAware, issueWarning, makeEarlyEvaluationContext

Field Detail

namespaces

protected HashMap<String,String> namespaces

variables

protected HashMap<StructuredQName,XPathVariable> variables

externalResolver

protected NamespaceResolver externalResolver

requiredContextItemType

protected ItemType requiredContextItemType

importedSchemaNamespaces

protected Set importedSchemaNamespaces

autoDeclare

protected boolean autoDeclare

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

Method Detail

getContainerGranularity

public int getContainerGranularity()

Get the granularity of the container.

Returns:

0 for a temporary container created during parsing; 1 for a container that operates at the level of an XPath expression; 2 for a container at the level of a global function or template

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.

setDefaultElementNamespace

public void setDefaultElementNamespace(String uri)

Set the default namespace for elements and types

Specified by:

setDefaultElementNamespace in interface XPathStaticContext

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, 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

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(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(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

iterateExternalVariables

public Iterator<XPathVariable> iterateExternalVariables()

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 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

Returns:

the corresponding namespace URI

Throws:

XPathException - if the prefix is not declared; the associated error code should be XPST0081

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

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

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.

isImportedSchema

public boolean isImportedSchema(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 Set<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(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

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

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