| java.lang.Object
 net.sf.saxon.pull.VirtualTreeWalker
| VirtualTreeWalker | | public class VirtualTreeWalker implements PullProvider,NamespaceDeclarations(Code) | | A virtual tree walker provides a sequence of pull events describing the structure and content of a tree
that is conceptually being constructed by expressions in a query or stylesheet; in fact the tree is
not necessarily constructed in memory, and exists only as this stream of pull events.
The tree is physically constructed if operations are requested that depend on the identity of the nodes
in the tree, or that navigate within the tree. Operations such as copying or atomizing the tree can be done
directly, without building it in memory. (Note however that if such operations are done more than once, the
underlying instructions may be evaluated repeatedly.)
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| Method Summary | |
| public void | close()
Close the event reader. | | public int | current()
Get the event most recently returned by next(), or by other calls that change
the position, for example getStringValue() and skipToMatchingEnd(). | | public AtomicValue | getAtomicValue()
Get an atomic value. | | public AttributeCollection | getAttributes()
Get the attributes associated with the current element. | | public int | getFingerprint()
Get the fingerprint of the name of the element. | | public int | getLength()
Get the number of declarations (and undeclarations) in this list. | | public int | getNameCode()
Get the nameCode identifying the name of the current node. | | public NamePool | getNamePool()
| | public int | getNamespaceCode(int index)
Get the n'th declaration in the list in the form of a namespace code. | | public int[] | getNamespaceCodes(int[] buffer)
Get all the namespace codes, as an array.
Parameters:
buffer - a sacrificial array that the method is free to use to contain the result.May be null. | | public NamespaceDeclarations | getNamespaceDeclarations()
Get the namespace declarations associated with the current element. | | public PipelineConfiguration | getPipelineConfiguration()
Get configuration information. | | public String | getPrefix(int index)
Get the prefix of the n'th declaration (or undeclaration) in the list,
counting from zero.
Parameters:
index - the index identifying which declaration is required. | | public SourceLocator | getSourceLocator()
Get the location of the current event.
For an event stream representing a real document, the location information
should identify the location in the lexical XML source. | | public CharSequence | getStringValue()
Get the string value of the current element, text node, processing-instruction,
or top-level attribute or namespace node, or atomic value.
In other situations the result is undefined and may result in an IllegalStateException.
If the most recent event was a
VirtualTreeWalker.START_ELEMENT , this method causes the content
of the element to be read. | | public int | getTypeAnnotation()
Get the type annotation of the current attribute or element node, or atomic value.
The result of this method is undefined unless the most recent event was START_ELEMENT,
ATTRIBUTE, or ATOMIC_VALUE.
the type annotation. | | public String | getURI(int index)
Get the namespace URI of the n'th declaration (or undeclaration) in the list,
counting from zero.
Parameters:
index - the index identifying which declaration is required. | | public int | next()
Get the next event
an integer code indicating the type of event. | | public void | setNameCode(int nameCode)
| | public void | setPipelineConfiguration(PipelineConfiguration pipe)
Set configuration information. | | public int | skipToMatchingEnd()
Skip the current subtree. |
| VirtualTreeWalker | | public VirtualTreeWalker(ParentNodeConstructor instruction, XPathContext context)(Code) | | Create a VirtualTreeWalker to navigate the tree constructed by evaluating a given instruction
in a given dyamic context
Parameters:
instruction - the instruction (this will always be an instruction that creates element ordocument nodes)
Parameters:
context - the dynamic evaluation context |
| close | | public void close()(Code) | | Close the event reader. This indicates that no further events are required.
It is not necessary to close an event reader after
VirtualTreeWalker.END_OF_INPUT has
been reported, but it is recommended to close it if reading terminates
prematurely. Once an event reader has been closed, the effect of further
calls on next() is undefined.
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| current | | public int current()(Code) | | Get the event most recently returned by next(), or by other calls that change
the position, for example getStringValue() and skipToMatchingEnd(). This
method does not change the position of the PullProvider.
the current event |
| getAtomicValue | | public AtomicValue getAtomicValue()(Code) | | Get an atomic value. This call may be used only when the last event reported was
ATOMIC_VALUE. This indicates that the PullProvider is reading a sequence that contains
a free-standing atomic value; it is never used when reading the content of a node.
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| getAttributes | | public AttributeCollection getAttributes() throws XPathException(Code) | | Get the attributes associated with the current element. This method must
be called only after a START_ELEMENT event has been notified. The contents
of the returned AttributeCollection are guaranteed to remain unchanged
until the next START_ELEMENT event, but may be modified thereafter. The object
should not be modified by the client.
Attributes may be read before or after reading the namespaces of an element,
but must not be read after the first child node has been read, or after calling
one of the methods skipToEnd(), getStringValue(), or getTypedValue().
an AttributeCollection representing the attributes of the elementthat has just been notified. |
| getFingerprint | | public int getFingerprint()(Code) | | Get the fingerprint of the name of the element. This is similar to the nameCode, except that
it does not contain any information about the prefix: so two elements with the same fingerprint
have the same name, excluding prefix. This method
can be used after the
VirtualTreeWalker.START_ELEMENT ,
VirtualTreeWalker.END_ELEMENT ,
VirtualTreeWalker.PROCESSING_INSTRUCTION ,
VirtualTreeWalker.ATTRIBUTE , or
VirtualTreeWalker.NAMESPACE events.
If called at other times, the result is undefined and may result in an IllegalStateException.
If called when the current node is an unnamed namespace node (a node representing the default namespace)
the returned value is -1.
the fingerprint. The fingerprint can be used to obtain the local nameand namespace URI from the name pool. |
| getLength | | public int getLength()(Code) | | Get the number of declarations (and undeclarations) in this list.
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| getNamespaceCodes | | public int[] getNamespaceCodes(int[] buffer)(Code) | | Get all the namespace codes, as an array.
Parameters:
buffer - a sacrificial array that the method is free to use to contain the result.May be null. an integer array containing namespace codes. The array may be filled completelywith namespace codes, or it may be incompletely filled, in which case a -1 integer actsas a terminator. |
| getNamespaceDeclarations | | public NamespaceDeclarations getNamespaceDeclarations() throws XPathException(Code) | | Get the namespace declarations associated with the current element. This method must
be called only after a START_ELEMENT event has been notified. In the case of a top-level
START_ELEMENT event (that is, an element that either has no parent node, or whose parent
is not included in the sequence being read), the NamespaceDeclarations object returned
will contain a namespace declaration for each namespace that is in-scope for this element
node. In the case of a non-top-level element, the NamespaceDeclarations will contain
a set of namespace declarations and undeclarations, representing the differences between
this element and its parent.
It is permissible for this method to return namespace declarations that are redundant.
The NamespaceDeclarations object is guaranteed to remain unchanged until the next START_ELEMENT
event, but may then be overwritten. The object should not be modified by the client.
Namespaces may be read before or after reading the attributes of an element,
but must not be read after the first child node has been read, or after calling
one of the methods skipToEnd(), getStringValue(), or getTypedValue(). *
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| getPrefix | | public String getPrefix(int index)(Code) | | Get the prefix of the n'th declaration (or undeclaration) in the list,
counting from zero.
Parameters:
index - the index identifying which declaration is required. the namespace prefix. For a declaration or undeclaration of thedefault namespace, this is the zero-length string.
throws:
IndexOutOfBoundsException - if the index is out of range. |
| getSourceLocator | | public SourceLocator getSourceLocator()(Code) | | Get the location of the current event.
For an event stream representing a real document, the location information
should identify the location in the lexical XML source. For a constructed document, it should
identify the location in the query or stylesheet that caused the node to be created.
A value of null can be returned if no location information is available.
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| getStringValue | | public CharSequence getStringValue() throws XPathException(Code) | | Get the string value of the current element, text node, processing-instruction,
or top-level attribute or namespace node, or atomic value.
In other situations the result is undefined and may result in an IllegalStateException.
If the most recent event was a
VirtualTreeWalker.START_ELEMENT , this method causes the content
of the element to be read. The current event on completion of this method will be the
corresponding
VirtualTreeWalker.END_ELEMENT . The next call of next() will return the event following
the END_ELEMENT event.
the String Value of the node in question, defined according to the rules in theXPath data model. |
| getTypeAnnotation | | public int getTypeAnnotation()(Code) | | Get the type annotation of the current attribute or element node, or atomic value.
The result of this method is undefined unless the most recent event was START_ELEMENT,
ATTRIBUTE, or ATOMIC_VALUE.
the type annotation. This code is the fingerprint of a type name, which may beresolved to a net.sf.saxon.type.SchemaType by access to the Configuration. |
| getURI | | public String getURI(int index)(Code) | | Get the namespace URI of the n'th declaration (or undeclaration) in the list,
counting from zero.
Parameters:
index - the index identifying which declaration is required. the namespace URI. For a namespace undeclaration, this is thezero-length string.
throws:
IndexOutOfBoundsException - if the index is out of range. |
| setNameCode | | public void setNameCode(int nameCode)(Code) | | Set the initial nameCode (the nameCode of the node at the root of the tree being walked)
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| setPipelineConfiguration | | public void setPipelineConfiguration(PipelineConfiguration pipe)(Code) | | Set configuration information. This must only be called before any events
have been read.
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| skipToMatchingEnd | | public int skipToMatchingEnd() throws XPathException(Code) | | Skip the current subtree. This method may be called only immediately after
a START_DOCUMENT or START_ELEMENT event. This call returns the matching
END_DOCUMENT or END_ELEMENT event; the next call on next() will return
the event following the END_DOCUMENT or END_ELEMENT.
throws:
IllegalStateException - if the method is called at any time other thanimmediately after a START_DOCUMENT or START_ELEMENT event. |
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