| package org.apache.xpath.objects; |
| |
| import org.apache.xml.dtm.DTM; |
| import org.apache.xml.dtm.DTMIterator; |
| import org.apache.xml.dtm.DTMFilter; |
| |
| import org.apache.xml.utils.XMLString; |
| |
| import org.apache.xpath.VariableComposeState; |
| import org.apache.xpath.XPathContext; |
| import org.apache.xpath.Expression; |
| import org.apache.xalan.res.XSLMessages; |
| import org.apache.xpath.res.XPATHErrorResources; |
| |
| /** |
| * This class makes an select statement act like an result tree fragment... |
| * at least in its returned values and comparisons. Actually, a |
| * more accurate description might be that its "values", like those of an |
| * RTF, spans all the selected content rather than being taken only from the |
| * first matching node. |
| * |
| * But this really _isn't_ a result tree fragment. The rtf() method is |
| * hardwired to throw an exception, and the type() method returns STRING. |
| * |
| * (Some of the logic is swiped from XRTreeFrag, but we no longer |
| * inherit from that class. Doing so was a bit of a kluge, and became |
| * impractical when XRTreeFrag was rewritten as an XNodeSet derivitive.) |
| * |
| * %REVIEW% Should we rename this class? |
| */ |
| public class XRTreeFragSelectWrapper extends XObject implements Cloneable |
| { |
| XObject m_selected; |
| boolean m_allowRelease; |
| Expression m_expr; |
| |
| public XRTreeFragSelectWrapper(Expression expr) |
| { |
| m_expr=expr; |
| } |
| |
| /** |
| * 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). |
| */ |
| public void fixupVariables(VariableComposeState vcs) |
| { |
| m_expr.fixupVariables(vcs); |
| } |
| |
| /** |
| * For support of literal objects in xpaths. |
| * |
| * @param xctxt The XPath execution context. |
| * |
| * @return This object. |
| * |
| * @throws javax.xml.transform.TransformerException |
| */ |
| public XObject execute(XPathContext xctxt) |
| throws javax.xml.transform.TransformerException |
| { |
| try |
| { |
| m_selected = m_expr.execute(xctxt); |
| m_selected.allowDetachToRelease(m_allowRelease); |
| XRTreeFragSelectWrapper xrtf = (XRTreeFragSelectWrapper)this.clone(); |
| return xrtf; |
| } |
| catch(CloneNotSupportedException cnse) |
| { |
| throw new javax.xml.transform.TransformerException(cnse); |
| } |
| |
| } |
| |
| /** |
| * Detaches the <code>DTMIterator</code> from the set which it iterated |
| * over, releasing any computational resources and placing the iterator |
| * in the INVALID state. After <code>detach</code> has been invoked, |
| * calls to <code>nextNode</code> or <code>previousNode</code> will |
| * raise a runtime exception. |
| * |
| * In general, detach should only be called once on the object. |
| */ |
| public void detach() |
| { |
| if(m_allowRelease) |
| { |
| m_selected.detach(); |
| m_selected = null; |
| m_expr=null; |
| } |
| |
| super.detach(); |
| } |
| |
| /** |
| * Cast result object to an XMLString. |
| * |
| * @return The document fragment node data or the empty string. |
| */ |
| public XMLString xstr() |
| { |
| return m_selected.xstr(); |
| } |
| |
| /** |
| * Cast result object to a string. |
| * |
| * @return The document fragment node data or the empty string. |
| */ |
| public String str() |
| { |
| return m_selected.str(); |
| } |
| |
| /** |
| * Tell what kind of class this is. |
| * |
| * @return type CLASS_RTREEFRAG |
| */ |
| public int getType() |
| { |
| return CLASS_STRING; |
| } |
| |
| /** |
| * Cast result object to a result tree fragment. |
| * Probably not needed since we no longer claim to inherit XRTreeFrag... |
| * |
| * @throws method-not-supported runtime expection. |
| */ |
| public int rtf() |
| { |
| throw new RuntimeException(XSLMessages.createXPATHMessage(XPATHErrorResources.ER_RTF_NOT_SUPPORTED_XRTREEFRAGSELECTWRAPPER, null)); //"rtf() not supported by XRTreeFragSelectWrapper!"); |
| } |
| |
| /** |
| * Cast result object to a DTMIterator. |
| * |
| * @return The document fragment as a DTMIterator |
| */ |
| public DTMIterator asNodeIterator() |
| { |
| throw new RuntimeException(XSLMessages.createXPATHMessage(XPATHErrorResources.ER_RTF_NOT_SUPPORTED_XRTREEFRAGSELECTWRAPPER, null)); //"asNodeIterator() not supported by XRTreeFragSelectWrapper!"); |
| } |
| |
| public Object object() |
| { |
| /* Would this be preferable? |
| if(m_selected!=null) |
| return m_selected.object(); |
| else |
| */ |
| return m_expr; |
| } |
| |
| |
| //------------------------------------------------------------- |
| // Code swiped from XRTreeFrag since we no longer inherit therefrom |
| |
| /** |
| * Tell if two objects are functionally equal. |
| * Use logic from XRTreeFrag, not standard XObject.equals() |
| * |
| * @param obj2 Object to compare this to |
| * |
| * @return True if the two objects are equal |
| * |
| * @throws javax.xml.transform.TransformerException |
| */ |
| public boolean equals(XObject obj2) |
| { |
| |
| try |
| { |
| if (XObject.CLASS_NODESET == obj2.getType()) |
| { |
| |
| // In order to handle the 'all' semantics of |
| // nodeset comparisons, we always call the |
| // nodeset function. |
| return ((XNodeSet)obj2).equalsExistential(this); |
| } |
| else if (XObject.CLASS_BOOLEAN == obj2.getType()) |
| { |
| return bool() == obj2.bool(); |
| } |
| else if (XObject.CLASS_NUMBER == obj2.getType()) |
| { |
| return num() == obj2.num(); |
| } |
| else if (XObject.CLASS_NODESET == obj2.getType()) |
| { |
| return xstr().equals(obj2.xstr()); |
| } |
| else if (XObject.CLASS_STRING == obj2.getType()) |
| { |
| return xstr().equals(obj2.xstr()); |
| } |
| else if (XObject.CLASS_RTREEFRAG == obj2.getType()) |
| { |
| |
| // Probably not so good. Think about this. |
| return xstr().equals(obj2.xstr()); |
| } |
| else |
| { |
| return super.equals(obj2); |
| } |
| } |
| catch(javax.xml.transform.TransformerException te) |
| { |
| throw new org.apache.xml.utils.WrappedRuntimeException(te); |
| } |
| } |
| |
| /** |
| * Cast result object to a number. |
| * Note that this is different from XNodeSet's definition; we convert |
| * the entire string content, not just item(0). |
| * |
| * @return The result tree fragment as a number or NaN |
| */ |
| public double num() |
| { |
| XMLString s = xstr(); |
| |
| return s.toDouble(); |
| } |
| |
| /** |
| * Cast result object to a boolean. This always returns true for an |
| * XRTreeFragSelectWrapper. (I'm not entirely sure why it should, but some |
| * of the regression tests fail if it doesn't.) |
| * |
| * @return true |
| */ |
| public boolean bool() |
| { |
| return true; |
| } |
| |
| |
| } |