net.sf.saxon.instruct

Class Attribute

public final class Attribute extends SimpleNodeConstructor

An instruction derived from an xsl:attribute element in stylesheet, or from an attribute constructor in XQuery
Constructor Summary
Attribute(Expression attributeName, Expression namespace, NamespaceResolver nsContext, int validationAction, SimpleType schemaType, int annotation, boolean allowNameAsQName)
Construct an Attribute instruction
Method Summary
voidcheckPermittedContents(SchemaType parentType, StaticContext env, boolean whole)
Check that any elements and attributes constructed or returned by this expression are acceptable in the content model of a given complex type.
intcomputeSpecialProperties()
Get the static properties of this expression (other than its type).
voiddisplay(int level, NamePool pool, PrintStream out)
Display this instruction as an expression, for diagnostics
protected intevaluateNameCode(XPathContext context)
intgetCardinality()
intgetInstructionNameCode()
Get the name of this instruction
ItemTypegetItemType(TypeHierarchy th)
IteratoriterateSubExpressions()
Get the subexpressions of this expression
voidlocalTypeCheck(StaticContext env, ItemType contextItemType)
TailCallprocessLeavingTail(XPathContext context)
Process this instruction
protected voidpromoteInst(PromotionOffer offer)
Offer promotion for subexpressions.
voidsetRejectDuplicates()
Indicate that two attributes with the same name are not acceptable.
Expressionsimplify(StaticContext env)

Constructor Detail

Attribute

public Attribute(Expression attributeName, Expression namespace, NamespaceResolver nsContext, int validationAction, SimpleType schemaType, int annotation, boolean allowNameAsQName)
Construct an Attribute instruction

Parameters: attributeName An expression to calculate the attribute name namespace An expression to calculate the attribute namespace nsContext a NamespaceContext object containing the static namespace context of the stylesheet instruction validationAction e.g. validation=strict, lax, strip, preserve schemaType Type against which the attribute must be validated. This must not be a namespace-sensitive type; it is the caller's responsibility to check this. annotation Integer code identifying the type named in the type attribute allowNameAsQName

Method Detail

checkPermittedContents

public void checkPermittedContents(SchemaType parentType, StaticContext env, boolean whole)
Check that any elements and attributes constructed or returned by this expression are acceptable in the content model of a given complex type. It's always OK to say yes, since the check will be repeated at run-time. The process of checking element and attribute constructors against the content model of a complex type also registers the type of content expected of those constructors, so the static validation can continue recursively.

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.

Returns: a set of flags indicating static properties of this expression

display

public void display(int level, NamePool pool, PrintStream out)
Display this instruction as an expression, for diagnostics

evaluateNameCode

protected int evaluateNameCode(XPathContext context)

getCardinality

public int getCardinality()

getInstructionNameCode

public int getInstructionNameCode()
Get the name of this instruction

getItemType

public ItemType getItemType(TypeHierarchy th)

iterateSubExpressions

public Iterator iterateSubExpressions()
Get the subexpressions of this expression

Returns: an iterator over the subexpressions

localTypeCheck

public void localTypeCheck(StaticContext env, ItemType contextItemType)

processLeavingTail

public TailCall processLeavingTail(XPathContext context)
Process this instruction

Parameters: context the dynamic context of the transformation

Returns: a TailCall to be executed by the caller, always null for this instruction

promoteInst

protected void promoteInst(PromotionOffer offer)
Offer promotion for subexpressions. The offer will be accepted if the subexpression is not dependent on the factors (e.g. the context item) identified in the PromotionOffer. By default the offer is not accepted - this is appropriate in the case of simple expressions such as constant values and variable references where promotion would give no performance advantage. This method is always called at compile time.

Parameters: offer details of the offer, for example the offer to move expressions that don't depend on the context to an outer level in the containing expression

Throws: XPathException if any error is detected

setRejectDuplicates

public void setRejectDuplicates()
Indicate that two attributes with the same name are not acceptable. (This option is set in XQuery, but not in XSLT)

simplify

public Expression simplify(StaticContext env)