File	Doc	Category	Size	Date	Package
Expression.java	API Doc	Java SE 5 API	17937	Fri Aug 26 14:56:06 BST 2005	com.sun.org.apache.xpath.internal

Expression

• java.lang.Object

Fields Summary
private ExpressionNode	m_parent The location where this expression was built from. Need for diagnostic messages. May be null.

Constructors Summary

Methods Summary
public com.sun.org.apache.xml.internal.dtm.DTMIterator	asIterator(com.sun.org.apache.xpath.internal.XPathContext xctxt, int contextNode) Given an select expression and a context, evaluate the XPath and return the resulting iterator. param xctxt The execution context. param contextNode The node that "." expresses. return A valid DTMIterator. throws TransformerException thrown if the active ProblemListener decides the error condition is severe enough to halt processing. throws javax.xml.transform.TransformerException xsl.usage experimental try { xctxt.pushCurrentNodeAndExpression(contextNode, contextNode); return execute(xctxt).iter(); } finally { xctxt.popCurrentNodeAndExpression(); }
public com.sun.org.apache.xml.internal.dtm.DTMIterator	asIteratorRaw(com.sun.org.apache.xpath.internal.XPathContext xctxt, int contextNode) Given an select expression and a context, evaluate the XPath and return the resulting iterator, but do not clone. param xctxt The execution context. param contextNode The node that "." expresses. return A valid DTMIterator. throws TransformerException thrown if the active ProblemListener decides the error condition is severe enough to halt processing. throws javax.xml.transform.TransformerException xsl.usage experimental try { xctxt.pushCurrentNodeAndExpression(contextNode, contextNode); XNodeSet nodeset = (XNodeSet)execute(xctxt); return nodeset.iterRaw(); } finally { xctxt.popCurrentNodeAndExpression(); }
public int	asNode(com.sun.org.apache.xpath.internal.XPathContext xctxt) Return the first node out of the nodeset, if this expression is a nodeset expression. param xctxt The XPath runtime context. return the first node out of the nodeset, or DTM.NULL. throws javax.xml.transform.TransformerException DTMIterator iter = execute(xctxt).iter(); return iter.nextNode();
public void	assertion(boolean b, java.lang.String msg) Tell the user of an assertion error, and probably throw an exception. param b If false, a runtime exception will be thrown. param msg The assertion message, which should be informative. throws RuntimeException if the b argument is false. throws javax.xml.transform.TransformerException if (!b) { java.lang.String fMsg = XSLMessages.createXPATHMessage( XPATHErrorResources.ER_INCORRECT_PROGRAMMER_ASSERTION, new Object[]{ msg }); throw new RuntimeException(fMsg); }
public boolean	bool(com.sun.org.apache.xpath.internal.XPathContext xctxt) Evaluate expression to a boolean. param xctxt The XPath runtime context. return false throws javax.xml.transform.TransformerException return execute(xctxt).bool();
public boolean	canTraverseOutsideSubtree() Tell if this expression or it's subexpressions can traverse outside the current subtree. return true if traversal outside the context node's subtree can occur. return false;
public abstract boolean	deepEquals(com.sun.org.apache.xpath.internal.Expression expr) Compare this object with another object and see if they are equal, include the sub heararchy. param expr Another expression object. return true if this objects class and the expr object's class are the same, and the data contained within both objects are considered equal.
public void	error(com.sun.org.apache.xpath.internal.XPathContext xctxt, java.lang.String msg, java.lang.Object[] args) Tell the user of an error, and probably throw an exception. param xctxt The XPath runtime context. param msg An error msgkey that corresponds to one of the constants found in {@link com.sun.org.apache.xpath.internal.res.XPATHErrorResources}, which is a key for a format string. param args An array of arguments represented in the format string, which may be null. throws TransformerException if the current ErrorListoner determines to throw an exception. throws javax.xml.transform.TransformerException java.lang.String fmsg = XSLMessages.createXPATHMessage(msg, args); if (null != xctxt) { ErrorListener eh = xctxt.getErrorListener(); TransformerException te = new TransformerException(fmsg, this); eh.fatalError(te); }
public com.sun.org.apache.xpath.internal.objects.XObject	execute(com.sun.org.apache.xpath.internal.XPathContext xctxt, int currentNode) Execute an expression in the XPath runtime context, and return the result of the expression. param xctxt The XPath runtime context. param currentNode The currentNode. return The result of the expression in the form of a XObject. throws javax.xml.transform.TransformerException if a runtime exception occurs. // For now, the current node is already pushed. return execute(xctxt);
public com.sun.org.apache.xpath.internal.objects.XObject	execute(com.sun.org.apache.xpath.internal.XPathContext xctxt, int currentNode, com.sun.org.apache.xml.internal.dtm.DTM dtm, int expType) Execute an expression in the XPath runtime context, and return the result of the expression. param xctxt The XPath runtime context. param currentNode The currentNode. param dtm The DTM of the current node. param expType The expanded type ID of the current node. return The result of the expression in the form of a XObject. throws javax.xml.transform.TransformerException if a runtime exception occurs. // For now, the current node is already pushed. return execute(xctxt);
public abstract com.sun.org.apache.xpath.internal.objects.XObject	execute(com.sun.org.apache.xpath.internal.XPathContext xctxt) Execute an expression in the XPath runtime context, and return the result of the expression. param xctxt The XPath runtime context. return The result of the expression in the form of a XObject. throws javax.xml.transform.TransformerException if a runtime exception occurs.
public com.sun.org.apache.xpath.internal.objects.XObject	execute(com.sun.org.apache.xpath.internal.XPathContext xctxt, boolean destructiveOK) Execute an expression in the XPath runtime context, and return the result of the expression, but tell that a "safe" object doesn't have to be returned. The default implementation just calls execute(xctxt). param xctxt The XPath runtime context. param destructiveOK true if a "safe" object doesn't need to be returned. return The result of the expression in the form of a XObject. throws javax.xml.transform.TransformerException if a runtime exception occurs. return execute(xctxt);
public void	executeCharsToContentHandler(com.sun.org.apache.xpath.internal.XPathContext xctxt, org.xml.sax.ContentHandler handler) Execute an expression in the XPath runtime context, and return the result of the expression. param xctxt The XPath runtime context. NEEDSDOC @param handler return The result of the expression in the form of a XObject. throws javax.xml.transform.TransformerException if a runtime exception occurs. throws org.xml.sax.SAXException XObject obj = execute(xctxt); obj.dispatchCharactersEvents(handler); obj.detach();
public void	exprAddChild(com.sun.org.apache.xpath.internal.ExpressionNode n, int i) This method tells the node to add its argument to the node's list of children. assertion(false, "exprAddChild method not implemented!");
public com.sun.org.apache.xpath.internal.ExpressionNode	exprGetChild(int i) This method returns a child node. The children are numbered from zero, left to right. return null;
public int	exprGetNumChildren() Return the number of children the node has. return 0;
public com.sun.org.apache.xpath.internal.ExpressionNode	exprGetParent() return m_parent;
public void	exprSetParent(com.sun.org.apache.xpath.internal.ExpressionNode n) This pair of methods are used to inform the node of its parent. assertion(n != this, "Can not parent an expression to itself!"); m_parent = n;
public abstract void	fixupVariables(java.util.Vector vars, int globalsSize) This function is used to fixup variables from QNames to stack frame indexes at stylesheet build time. param vars List of QNames that correspond to variables. This list should be searched backwards for the first qualified name that corresponds to the variable reference qname. The position of the QName in the vector from the start of the vector will be its position in the stack frame (but variables above the globalsTop value will need to be offset to the current stack frame). NEEDSDOC @param globalsSize
public int	getColumnNumber() Return the character position where the current document event ends. Warning: The return value from the method is intended only as an approximation for the sake of error reporting; it is not intended to provide sufficient information to edit the character content of the original XML document. The return value is an approximation of the column number in the document entity or external parsed entity where the markup that triggered the event appears. return The column number, or -1 if none is available. see #getLineNumber if(null == m_parent) return 0; return m_parent.getColumnNumber();
public com.sun.org.apache.xpath.internal.ExpressionNode	getExpressionOwner() Get the first non-Expression parent of this node. return null or first ancestor that is not an Expression. ExpressionNode parent = exprGetParent(); while((null != parent) && (parent instanceof Expression)) parent = parent.exprGetParent(); return parent;
public int	getLineNumber() Return the line number where the current document event ends. Warning: The return value from the method is intended only as an approximation for the sake of error reporting; it is not intended to provide sufficient information to edit the character content of the original XML document. The return value is an approximation of the line number in the document entity or external parsed entity where the markup that triggered the event appears. return The line number, or -1 if none is available. see #getColumnNumber if(null == m_parent) return 0; return m_parent.getLineNumber();
public java.lang.String	getPublicId() Return the public identifier for the current document event. The return value is the public identifier of the document entity or of the external parsed entity in which the markup that triggered the event appears. return A string containing the public identifier, or null if none is available. see #getSystemId if(null == m_parent) return null; return m_parent.getPublicId();
public java.lang.String	getSystemId() Return the system identifier for the current document event. The return value is the system identifier of the document entity or of the external parsed entity in which the markup that triggered the event appears. If the system identifier is a URL, the parser must resolve it fully before passing it to the application. return A string containing the system identifier, or null if none is available. see #getPublicId if(null == m_parent) return null; return m_parent.getSystemId();
public boolean	isNodesetExpr() Tell if the expression is a nodeset expression. In other words, tell if you can execute {@link asNode() asNode} without an exception. return true if the expression can be represented as a nodeset. return false;
protected final boolean	isSameClass(com.sun.org.apache.xpath.internal.Expression expr) This is a utility method to tell if the passed in class is the same class as this. It is to be used by the deepEquals method. I'm bottlenecking it here because I'm not totally confident that comparing the class objects is the best way to do this. return true of the passed in class is the exact same class as this class. if(null == expr) return false; return (getClass() == expr.getClass());
public boolean	isStableNumber() Tell if this expression returns a stable number that will not change during iterations within the expression. This is used to determine if a proximity position predicate can indicate that no more searching has to occur. return true if the expression represents a stable number. return false;
public double	num(com.sun.org.apache.xpath.internal.XPathContext xctxt) Evaluate expression to a number. param xctxt The XPath runtime context. return The expression evaluated as a double. throws javax.xml.transform.TransformerException return execute(xctxt).num();
public void	warn(com.sun.org.apache.xpath.internal.XPathContext xctxt, java.lang.String msg, java.lang.Object[] args) Warn the user of an problem. param xctxt The XPath runtime context. param msg An error msgkey that corresponds to one of the conststants found in {@link com.sun.org.apache.xpath.internal.res.XPATHErrorResources}, which is a key for a format string. param args An array of arguments represented in the format string, which may be null. throws TransformerException if the current ErrorListoner determines to throw an exception. throws javax.xml.transform.TransformerException java.lang.String fmsg = XSLMessages.createXPATHWarning(msg, args); if (null != xctxt) { ErrorListener eh = xctxt.getErrorListener(); // TO DO: Need to get stylesheet Locator from here. eh.warning(new TransformerException(fmsg, xctxt.getSAXLocator())); }
public com.sun.org.apache.xml.internal.utils.XMLString	xstr(com.sun.org.apache.xpath.internal.XPathContext xctxt) Cast result object to a string. param xctxt The XPath runtime context. return The string this wraps or the empty string if null throws javax.xml.transform.TransformerException return execute(xctxt).xstr();