/**
* Build the grouping table forming groups of items with equal keys. This form of grouping allows
* a member of the population to be present in zero or more groups, one for each value of the
* grouping key.
*/
private void buildIndexedGroups() throws XPathException {
HashMap index = new HashMap(40);
XPathContext c2 = keyContext.newMinorContext();
c2.setCurrentIterator(population);
while (true) {
Item item = population.next();
if (item == null) {
break;
}
processItem(index, item, c2);
}
}
private void runAdjacent() throws SaxonApiException {
TreeWriter treeWriter = null;
String last = null;
boolean open = false;
int count = 0;
while (source.moreDocuments()) {
count++;
source.read();
}
source.resetReader();
DocumentSequenceIterator xsi = new DocumentSequenceIterator(); // See below
xsi.setLast(count);
int pos = 0;
while (source.moreDocuments()) {
XdmNode node = source.read();
pos++;
Item item = null;
try {
XPathCompiler xcomp = runtime.getProcessor().newXPathCompiler();
xcomp.setBaseURI(step.getNode().getBaseURI());
for (String prefix : groupAdjacent.getNamespaceBindings().keySet()) {
xcomp.declareNamespace(prefix, groupAdjacent.getNamespaceBindings().get(prefix));
}
XPathExecutable xexec = xcomp.compile(groupAdjacent.getString());
// From Michael Kay: http://markmail.org/message/vkb2vaq2miylgndu
//
// Underneath the s9api XPathExecutable is a net.sf.saxon.sxpath.XPathExpression.
XPathExpression xexpr = xexec.getUnderlyingExpression();
// Call createDynamicContext() on this to get an XPathDynamicContext object;
XPathDynamicContext xdc = xexpr.createDynamicContext(node.getUnderlyingNode());
// call getXPathContextObject() on that to get the underlying XPathContext.
XPathContext xc = xdc.getXPathContextObject();
// Then call XPathContext.setCurrentIterator()
// to supply a SequenceIterator whose current() and position() methods return
// the context item and position respectively. If there's any risk that the
// expression will call the last() method, then it's simplest to make your
// iterator's getProperties() return LAST_POSITION_FINDER, and implement the
// LastPositionFinder interface, in which case last() will be implemented by
// calling the iterator's getLastPosition() method. (Otherwise last() is
// implemented by calling getAnother() to clone the iterator and calling next()
// on the clone until the end of the sequence is reached).
xsi.setPosition(pos);
xsi.setItem(node.getUnderlyingNode());
xc.setCurrentIterator(xsi);
// Then evaluate the expression by calling iterate() on the
// net.sf.saxon.sxpath.XPathExpression object.
SequenceIterator results = xexpr.iterate(xdc);
item = results.next();
if (item == null) {
throw new XProcException(
step.getNode(), "The group-adjacent expression returned nothing.");
}
if (results.next() != null) {
throw new XProcException(
step.getNode(), "Didn't expect group-adjacent to return a sequence!");
}
} catch (XPathException xe) {
throw new XProcException(xe);
}
//
// Good luck!
//
// FIXME: Compute effective boolean value in a more robust way
String cur = item.getStringValue();
if (last != null) {
if (last.equals(cur)) {
treeWriter.addSubtree(node);
} else {
if (open) {
open = false;
treeWriter.addEndElement();
treeWriter.endDocument();
result.write(treeWriter.getResult());
}
}
}
if (last == null || !last.equals(cur)) {
last = cur;
open = true;
treeWriter = new TreeWriter(runtime);
treeWriter.startDocument(step.getNode().getBaseURI());
treeWriter.addStartElement(wrapper);
treeWriter.startContent();
treeWriter.addSubtree(node);
}
}
if (open) {
open = false;
treeWriter.addEndElement();
treeWriter.endDocument();
result.write(treeWriter.getResult());
}
}
