Package net.sf.saxon.functions
Class Id
java.lang.Object
net.sf.saxon.expr.Expression
net.sf.saxon.expr.FunctionCall
net.sf.saxon.functions.SystemFunction
net.sf.saxon.functions.Id
- All Implemented Interfaces:
Serializable
,SourceLocator
,LocationProvider
,SaxonLocator
,EvaluableItem
,SequenceIterable
,InstructionInfo
,Locator
The XPath 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:
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Field Summary
Fields inherited from class net.sf.saxon.functions.SystemFunction
operation
Fields inherited from class net.sf.saxon.expr.FunctionCall
argument
Fields inherited from class net.sf.saxon.expr.Expression
EVALUATE_METHOD, ITERATE_METHOD, locationId, PROCESS_METHOD, staticProperties
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionaddToPathMap
(PathMap pathMap, PathMap.PathMapNodeSet pathMapNodeSet) Add a representation of a doc() call or similar function to a PathMap.void
checkArguments
(ExpressionVisitor visitor) Static analysis: prevent sorting of the argumentint
Get the static properties of this expression (other than its type).static SequenceIterator
getIdMultiple
(DocumentInfo doc, SequenceIterator idrefs) 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, String idrefs) Get an iterator over the nodes that have an id equal to one of the values is a whitespace separated stringiterate
(XPathContext context) Evaluate the function to return an iteration of selected nodes.preEvaluate
(ExpressionVisitor visitor) preEvaluate: this method suppresses compile-time evaluation by doing nothingsimplify
(ExpressionVisitor visitor) Simplify: add a second implicit argument, the context documentMethods inherited from class net.sf.saxon.functions.SystemFunction
addContextDocumentArgument, addDocToPathMap, computeCardinality, copy, getDetails, getErrorCodeForTypeErrors, getItemType, getRequiredType, makeSystemFunction, optimize, setDetails, useContextItemAsDefault
Methods inherited from class net.sf.saxon.expr.FunctionCall
addExternalFunctionCallToPathMap, checkArgumentCount, equals, explain, getArguments, getDisplayName, getFunctionName, getNumberOfArguments, hashCode, iterateSubExpressions, promote, replaceSubExpression, setArguments, setFunctionName, simplifyArguments, toString, typeCheck
Methods inherited from class net.sf.saxon.expr.Expression
adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, display, doPromotion, dynamicError, effectiveBooleanValue, evaluateAsString, evaluateItem, evaluatePendingUpdates, explain, findParentOf, getCardinality, getColumnNumber, getColumnNumber, getConstructType, getContainer, getDependencies, getExecutable, getHostLanguage, getImplementationMethod, getIntrinsicDependencies, getLineNumber, getLineNumber, getLocationId, getLocationProvider, getObjectName, getProperties, getProperty, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, getSystemId, hasLoopingSubexpression, implementsStaticTypeCheck, isUpdatingExpression, iterateEvents, markTailFunctionCalls, process, resetLocalStaticProperties, setContainer, setFiltered, setFlattened, setLocationId, staticTypeCheck, suppressValidation, typeError
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Constructor Details
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Id
public Id()
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Method Details
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simplify
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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checkArguments
Static analysis: prevent sorting of the argument- Overrides:
checkArguments
in classSystemFunction
- Parameters:
visitor
- the expression visitor- Throws:
XPathException
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preEvaluate
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
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
Evaluate the function to return an iteration of selected nodes.- Specified by:
iterate
in interfaceSequenceIterable
- 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
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 document- 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) 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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