Class ComputedAttribute

    • Constructor Detail

      • ComputedAttribute

        public ComputedAttribute​(Expression attributeName,
                                 Expression namespace,
                                 int validationAction,
                                 SimpleType schemaType,
                                 boolean allowNameAsQName)
        Construct an Attribute instruction
        Parameters:
        attributeName - An expression to calculate the attribute name
        namespace - An expression to calculate the attribute namespace
        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.
        allowNameAsQName - true if the attributeName expression is allowed to evaluate to a value of type xs:QName (true in XQuery, false in XSLT)
    • Method Detail

      • 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)
        Overrides:
        setRejectDuplicates in class AttributeCreator
      • getInstructionNameCode

        public int getInstructionNameCode()
        Get the name of this instruction
        Overrides:
        getInstructionNameCode in class Instruction
        Returns:
        a code identifying the instruction: typically but not always the fingerprint of a name in the XSLT namespace
      • getNameExp

        public Expression getNameExp()
        Get the expression used to compute the name of the attribute
        Returns:
        the expression used to compute the name of the attribute
      • getNamespaceExp

        public Expression getNamespaceExp()
        Get the expression used to compute the namespace part of the name of the attribute
        Returns:
        the expression used to compute the namespace part of the name of the attribute
      • setNameExp

        public void setNameExp​(Expression attributeName)
      • setNamespace

        public void setNamespace​(Expression namespace)
      • operands

        public java.lang.Iterable<Operand> operands()
        Description copied from class: Expression
        Get the immediate sub-expressions of this expression, with information about the relationship of each expression to its parent expression.

        If the expression is a Callable, then it is required that the order of the operands returned by this function is the same as the order of arguments supplied to the corresponding call() method.

        Overrides:
        operands in class SimpleNodeConstructor
        Returns:
        an iterator containing the sub-expressions of this expression
      • getNamespaceResolver

        public NamespaceResolver getNamespaceResolver()
        Get the namespace resolver used to resolve any prefix in the name of the attribute
        Returns:
        the namespace resolver if one has been saved; or null otherwise
      • getItemType

        public ItemType getItemType()
        Get the static type of this expression
        Overrides:
        getItemType in class AttributeCreator
        Returns:
        the static type of the item returned by this expression
      • getCardinality

        public int getCardinality()
        Get the static cardinality of this expression
        Overrides:
        getCardinality in class Expression
        Returns:
        the static cardinality (exactly one)
      • isAllowNameAsQName

        public boolean isAllowNameAsQName()
        Ask whether it is allowed for the name to be evaluted as an xs:QName instance (true in XQuery)
        Returns:
        the boolean if name is allowed as a QName
      • computeSpecialProperties

        protected 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 class AttributeCreator
        Returns:
        a set of flags indicating static properties of this expression
      • optimize

        public Expression optimize​(ExpressionVisitor visitor,
                                   ContextItemStaticInfo contextItemType)
                            throws XPathException
        Description copied from class: Expression
        Perform optimisation of an expression and its subexpressions. This is the third and final phase of static optimization.

        This method is called after all references to functions and variables have been resolved to the declaration of the function or variable, and after all type checking has been done.

        Overrides:
        optimize in class SimpleNodeConstructor
        Parameters:
        visitor - an expression visitor
        contextItemType - 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 to Type.ITEM_TYPE
        Returns:
        the original expression, rewritten if appropriate to optimize execution
        Throws:
        XPathException - if an error is discovered during this phase (typically a type error)
      • copy

        public Expression copy​(RebindingMap rebindings)
        Copy an expression. This makes a deep copy.
        Specified by:
        copy in class Expression
        Parameters:
        rebindings - a mutable list of (old binding, new binding) pairs that is used to update the bindings held in any local variable references that are copied.
        Returns:
        the copy of the original expression
      • checkPermittedContents

        public void checkPermittedContents​(SchemaType parentType,
                                           boolean whole)
                                    throws XPathException
        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.
        Overrides:
        checkPermittedContents in class Expression
        Parameters:
        parentType - the "given complex type": the method is checking that the nodes returned by this expression are acceptable members of the content model of this type
        whole - if true, we want to check that the value of this expression satisfies the content model as a whole; if false we want to check that the value of the expression is acceptable as one part of the content
        Throws:
        XPathException - if the value delivered by this expression cannot be part of the content model of the given type
      • evaluateNodeName

        public NodeName evaluateNodeName​(XPathContext context)
                                  throws XPathException
        Determine the name to be used for the attribute, as an integer name code
        Overrides:
        evaluateNodeName in class SimpleNodeConstructor
        Parameters:
        context - Dynamic evaluation context
        Returns:
        the integer name code for the attribute name
        Throws:
        XPathException - if a dynamic error occurs (for example, if the attribute name is invalid)
      • evaluateItem

        public Item evaluateItem​(XPathContext context)
                          throws XPathException
        Description copied from class: SimpleNodeConstructor
        Evaluate as an expression.
        Overrides:
        evaluateItem in class SimpleNodeConstructor
        Parameters:
        context - The context in which the expression is to be evaluated
        Returns:
        the node or atomic value that results from evaluating the expression; or null to indicate that the result is an empty sequence
        Throws:
        XPathException - if any dynamic error occurs evaluating the expression
      • export

        public void export​(ExpressionPresenter out)
                    throws XPathException
        Diagnostic print of expression structure. The abstract expression tree is written to the supplied output destination.
        Specified by:
        export in interface ExportAgent
        Specified by:
        export in class Expression
        Parameters:
        out - the expression presenter used to display the structure
        Throws:
        XPathException - if the export fails, for example if an expression is found that won't work in the target environment.