Class SingletonExpression

    • Constructor Detail

      • SingletonExpression

        public SingletonExpression()
    • Method Detail

      • isContextDocumentNodeSet

        public boolean isContextDocumentNodeSet()
        Determine, in the case of an expression whose data type is Value.NODESET, whether all the nodes in the node-set are guaranteed to come from the same document as the context node. Used for optimization.
        Overrides:
        isContextDocumentNodeSet in class Expression
      • selectFirst

        public NodeInfo selectFirst​(Context context)
                             throws XPathException
        Return the first node selected by this Expression when evaluated in the current context
        Overrides:
        selectFirst in class NodeSetExpression
        Parameters:
        context - The context for the evaluation
        Returns:
        the NodeInfo of the first node in document order, or null if the node-set is empty.
        Throws:
        XPathException
      • enumerate

        public NodeEnumeration enumerate​(Context context,
                                         boolean sort)
                                  throws XPathException
        Evaluate the expression in a given context to return a Node enumeration
        Specified by:
        enumerate in class NodeSetExpression
        Parameters:
        context - the evaluation context
        sort - Indicates result must be in document order
        Throws:
        XPathException - when the expression does not return a nodeset.
      • evaluateAsNodeSet

        public NodeSetValue evaluateAsNodeSet​(Context context)
                                       throws XPathException
        Evaluate an expression as a NodeSet.
        Overrides:
        evaluateAsNodeSet in class NodeSetExpression
        Parameters:
        context - The context in which the expression is to be evaluated
        Returns:
        the value of the expression, evaluated in the current context
        Throws:
        XPathException - when the expression does not return a nodeset.
      • evaluateAsString

        public java.lang.String evaluateAsString​(Context context)
                                          throws XPathException
        Evaluate as a string. Returns the string value of the node if it exists
        Overrides:
        evaluateAsString in class NodeSetExpression
        Parameters:
        context - The context in which the expression is to be evaluated
        Returns:
        true if there are any nodes selected by the NodeSetExpression
        Throws:
        XPathException
      • evaluateAsBoolean

        public boolean evaluateAsBoolean​(Context context)
                                  throws XPathException
        Evaluate as a boolean. Returns true if there are any nodes selected by the NodeSetExpression
        Overrides:
        evaluateAsBoolean in class NodeSetExpression
        Parameters:
        context - The context in which the expression is to be evaluated
        Returns:
        true if there are any nodes selected by the NodeSetExpression
        Throws:
        XPathException