Package net.sf.saxon.functions
Class Id
- java.lang.Object
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- net.sf.saxon.expr.Expression
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- net.sf.saxon.expr.FunctionCall
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- net.sf.saxon.functions.SystemFunction
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- net.sf.saxon.functions.Id
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- All Implemented Interfaces:
java.io.Serializable
,javax.xml.transform.SourceLocator
,LocationProvider
,SaxonLocator
,CallableExpression
,InstructionInfo
,org.xml.sax.Locator
public class Id extends SystemFunction implements CallableExpression
The XPath id() or element-with-id() function XPath 2.0 version: accepts any sequence as the first parameter; each item in the sequence is taken as an IDREFS value, that is, a space-separated list of ID values. Also accepts an optional second argument to identify the target document, this defaults to the context node.- See Also:
- Serialized Form
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Field Summary
Fields Modifier and Type Field Description static int
ELEMENT_WITH_ID
static int
ID
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Fields inherited from class net.sf.saxon.functions.SystemFunction
operation
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Fields inherited from class net.sf.saxon.expr.FunctionCall
argument
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Fields inherited from class net.sf.saxon.expr.Expression
EFFECTIVE_BOOLEAN_VALUE, EVALUATE_METHOD, EVENT_FEED_METHOD, ITEM_FEED_METHOD, ITERATE_METHOD, locationId, MAX_SEQUENCE_LENGTH, MAX_STRING_LENGTH, PROCESS_METHOD, PUSH_SELECTION, staticProperties, UNBOUNDED_LOWER, UNBOUNDED_UPPER, WATCH_METHOD
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Constructor Summary
Constructors Constructor Description Id()
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description PathMap.PathMapNodeSet
addToPathMap(PathMap pathMap, PathMap.PathMapNodeSet pathMapNodeSet)
Add a representation of a doc() call or similar function to a PathMap.SequenceIterator
call(SequenceIterator[] arguments, XPathContext context)
Evaluate the expressionvoid
checkArguments(ExpressionVisitor visitor)
Static analysis: prevent sorting of the argumentint
computeSpecialProperties()
Get the static properties of this expression (other than its type).static SequenceIterator
getIdMultiple(DocumentInfo doc, SequenceIterator idrefs, int operation)
Get an iterator over the nodes that have an id equal to one of the values is a set of whitespace separated stringsstatic SequenceIterator
getIdSingle(DocumentInfo doc, java.lang.String idrefs, int operation)
Get an iterator over the nodes that have an id equal to one of the values is a whitespace separated stringSequenceIterator
iterate(XPathContext context)
Evaluate the function to return an iteration of selected nodes.Expression
preEvaluate(ExpressionVisitor visitor)
preEvaluate: this method suppresses compile-time evaluation by doing nothingExpression
simplify(ExpressionVisitor visitor)
Simplify: add a second implicit argument, the context documentExpression
typeCheck(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType)
Type-check the expression.-
Methods inherited from class net.sf.saxon.functions.SystemFunction
addContextDocumentArgument, addDocToPathMap, computeCardinality, copy, equals, getDetails, getErrorCodeForTypeErrors, getImplementationMethod, getItemType, getOperation, getRequiredType, makeSystemFunction, optimize, setDetails, useContextItemAsDefault
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Methods inherited from class net.sf.saxon.expr.FunctionCall
addExternalFunctionCallToPathMap, checkArgumentCount, explain, getArguments, getDisplayName, getExpressionName, getFunctionName, getNumberOfArguments, hashCode, iterateSubExpressions, promote, replaceSubExpression, setArguments, setFunctionName, simplifyArguments, toString
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Methods inherited from class net.sf.saxon.expr.Expression
adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, effectiveBooleanValue, evaluateAsString, evaluateItem, evaluatePendingUpdates, explain, getCardinality, getColumnNumber, getColumnNumber, getConstructType, getContainer, getDependencies, getEvaluationMethod, getExecutable, getHostLanguage, getIntegerBounds, getIntrinsicDependencies, getLineNumber, getLineNumber, getLocationId, getLocationProvider, getObjectName, getProperties, getProperty, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, getSystemId, hasLoopingSubexpression, hasVariableBinding, implementsStaticTypeCheck, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, iterateEvents, iterateSameFocusSubExpressions, markTailFunctionCalls, process, resetLocalStaticProperties, setContainer, setEvaluationMethod, setFiltered, setFlattened, setLocationId, staticTypeCheck, suppressValidation, typeError
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Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
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Methods inherited from interface net.sf.saxon.expr.CallableExpression
getArguments
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Field Detail
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ID
public static final int ID
- See Also:
- Constant Field Values
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ELEMENT_WITH_ID
public static final int ELEMENT_WITH_ID
- See Also:
- Constant Field Values
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Method Detail
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simplify
public Expression simplify(ExpressionVisitor visitor) throws XPathException
Simplify: add a second implicit argument, the context document- Overrides:
simplify
in classFunctionCall
- Parameters:
visitor
- an expression visitor- Returns:
- the simplified expression
- Throws:
XPathException
- if an error is discovered during expression rewriting
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typeCheck
public Expression typeCheck(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) throws XPathException
Type-check the expression. This also calls preEvaluate() to evaluate the function if all the arguments are constant; functions that do not require this behavior can override the preEvaluate method.- Overrides:
typeCheck
in classFunctionCall
- Parameters:
visitor
- an expression visitorcontextItemType
- the static type of "." at the point where this expression is invoked. The parameter is set to null if it is known statically that the context item will be undefined. If the type of the context item is not known statically, the argument is set toType.ITEM_TYPE
- Returns:
- the original expression, rewritten to perform necessary run-time type checks, and to perform other type-related optimizations
- Throws:
XPathException
- if an error is discovered during this phase (typically a type error)
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checkArguments
public void checkArguments(ExpressionVisitor visitor) throws XPathException
Static analysis: prevent sorting of the argument- Overrides:
checkArguments
in classSystemFunction
- Parameters:
visitor
- the expression visitor- Throws:
XPathException
- if the arguments are incorrect
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preEvaluate
public Expression preEvaluate(ExpressionVisitor visitor)
preEvaluate: this method suppresses compile-time evaluation by doing nothing- Overrides:
preEvaluate
in classFunctionCall
- Parameters:
visitor
- an expression visitor- Returns:
- the result of the early evaluation, or the original expression, or potentially a simplified expression
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computeSpecialProperties
public int computeSpecialProperties()
Get the static properties of this expression (other than its type). The result is bit-signficant. These properties are used for optimizations. In general, if property bit is set, it is true, but if it is unset, the value is unknown.- Overrides:
computeSpecialProperties
in classSystemFunction
- Returns:
- the special properties, as a bit-significant integer
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addToPathMap
public PathMap.PathMapNodeSet addToPathMap(PathMap pathMap, PathMap.PathMapNodeSet pathMapNodeSet)
Add a representation of a doc() call or similar function to a PathMap. This is a convenience method called by the addToPathMap() methods for doc(), document(), collection() and similar functions. These all create a new root expression in the path map.- Overrides:
addToPathMap
in classExpression
- Parameters:
pathMap
- the PathMap to which the expression should be addedpathMapNodeSet
-- Returns:
- the pathMapNode representing the focus established by this expression, in the case where this expression is the first operand of a path expression or filter expression
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iterate
public SequenceIterator iterate(XPathContext context) throws XPathException
Evaluate the function to return an iteration of selected nodes.- Overrides:
iterate
in classExpression
- Parameters:
context
- supplies the context for evaluation- Returns:
- a SequenceIterator that can be used to iterate over the result of the expression
- Throws:
XPathException
- if any dynamic error occurs evaluating the expression
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getIdSingle
public static SequenceIterator getIdSingle(DocumentInfo doc, java.lang.String idrefs, int operation) throws XPathException
Get an iterator over the nodes that have an id equal to one of the values is a whitespace separated string- Parameters:
doc
- The document to be searchedidrefs
- a string containing zero or more whitespace-separated ID values to be found in the documentoperation
- eitherID
orELEMENT_WITH_ID
- Returns:
- an iterator over the nodes whose ID is one of the specified values
- Throws:
XPathException
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getIdMultiple
public static SequenceIterator getIdMultiple(DocumentInfo doc, SequenceIterator idrefs, int operation) throws XPathException
Get an iterator over the nodes that have an id equal to one of the values is a set of whitespace separated strings- Parameters:
doc
- The document to be searchedidrefs
- an iterator over a set of strings each of which is a string containing zero or more whitespace-separated ID values to be found in the document- Returns:
- an iterator over the nodes whose ID is one of the specified values
- Throws:
XPathException
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call
public SequenceIterator call(SequenceIterator[] arguments, XPathContext context) throws XPathException
Evaluate the expression- Specified by:
call
in interfaceCallableExpression
- Parameters:
arguments
- the values of the arguments, supplied as SequenceIteratorscontext
- the dynamic evaluation context- Returns:
- the result of the evaluation, in the form of a SequenceIterator
- Throws:
XPathException
- if a dynamic error occurs during the evaluation of the expression
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