/**
* Get a DTM to be used as a container for a dynamic Result Tree Fragment. This will always be an
* instance of (derived from? equivalent to?) SAX2DTM, since each RTF is constructed by
* temporarily redirecting our SAX output to it. It may be a single DTM containing for multiple
* fragments, if the implementation supports that.
*
* @return a non-null DTM reference.
*/
public DTM getRTFDTM() {
SAX2RTFDTM rtfdtm;
// We probably should _NOT_ be applying whitespace filtering at this stage!
//
// Some magic has been applied in DTMManagerDefault to recognize this set of options
// and generate an instance of DTM which can contain multiple documents
// (SAX2RTFDTM). Perhaps not the optimal way of achieving that result, but
// I didn't want to change the manager API at this time, or expose
// too many dependencies on its internals. (Ideally, I'd like to move
// isTreeIncomplete all the way up to DTM, so we wouldn't need to explicitly
// specify the subclass here.)
if (m_rtfdtm_stack == null) {
m_rtfdtm_stack = new Vector();
rtfdtm = (SAX2RTFDTM) m_dtmManager.getDTM(null, true, null, false, false);
m_rtfdtm_stack.addElement(rtfdtm);
++m_which_rtfdtm;
} else if (m_which_rtfdtm < 0) {
rtfdtm = (SAX2RTFDTM) m_rtfdtm_stack.elementAt(++m_which_rtfdtm);
} else {
rtfdtm = (SAX2RTFDTM) m_rtfdtm_stack.elementAt(m_which_rtfdtm);
// It might already be under construction -- the classic example would be
// an xsl:variable which uses xsl:call-template as part of its value. To
// handle this recursion, we have to start a new RTF DTM, pushing the old
// one onto a stack so we can return to it. This is not as uncommon a case
// as we might wish, unfortunately, as some folks insist on coding XSLT
// as if it were a procedural language...
if (rtfdtm.isTreeIncomplete()) {
if (++m_which_rtfdtm < m_rtfdtm_stack.size())
rtfdtm = (SAX2RTFDTM) m_rtfdtm_stack.elementAt(m_which_rtfdtm);
else {
rtfdtm = (SAX2RTFDTM) m_dtmManager.getDTM(null, true, null, false, false);
m_rtfdtm_stack.addElement(rtfdtm);
}
}
}
return rtfdtm;
}
/**
* Get a DTM to be used as a container for a global Result Tree Fragment. This will always be an
* instance of (derived from? equivalent to?) SAX2DTM, since each RTF is constructed by
* temporarily redirecting our SAX output to it. It may be a single DTM containing for multiple
* fragments, if the implementation supports that.
*
* <p>Note: The distinction between this method and getRTFDTM() is that the latter allocates space
* from the dynamic variable stack (m_rtfdtm_stack), which may be pruned away again as the
* templates which defined those variables are exited. Global variables may be bound late (see
* XUnresolvedVariable), and never want to be discarded, hence we need to allocate them separately
* and don't actually need a stack to track them.
*
* @return a non-null DTM reference.
*/
public DTM getGlobalRTFDTM() {
// We probably should _NOT_ be applying whitespace filtering at this stage!
//
// Some magic has been applied in DTMManagerDefault to recognize this set of options
// and generate an instance of DTM which can contain multiple documents
// (SAX2RTFDTM). Perhaps not the optimal way of achieving that result, but
// I didn't want to change the manager API at this time, or expose
// too many dependencies on its internals. (Ideally, I'd like to move
// isTreeIncomplete all the way up to DTM, so we wouldn't need to explicitly
// specify the subclass here.)
// If it doesn't exist, or if the one already existing is in the middle of
// being constructed, we need to obtain a new DTM to write into. I'm not sure
// the latter will ever arise, but I'd rather be just a bit paranoid..
if (m_global_rtfdtm == null || m_global_rtfdtm.isTreeIncomplete()) {
m_global_rtfdtm = (SAX2RTFDTM) m_dtmManager.getDTM(null, true, null, false, false);
}
return m_global_rtfdtm;
}
