@Override
public NodeIter iter(final QueryContext ctx) throws QueryException {
final Value v = checkCtx(ctx);
if (!v.type.isNode()) NODESPATH.thrw(input, AxisStep.this, v.type);
final AxisIter ai = axis.iter((ANode) v);
final NodeCache nc = new NodeCache();
for (ANode n; (n = ai.next()) != null; ) if (test.eval(n)) nc.add(n.finish());
// evaluate predicates
for (final Expr p : preds) {
ctx.size = nc.size();
ctx.pos = 1;
int c = 0;
for (int n = 0; n < nc.size(); ++n) {
ctx.value = nc.get(n);
final Item i = p.test(ctx, input);
if (i != null) {
// assign score value
nc.get(n).score(i.score());
nc.item[c++] = nc.get(n);
}
ctx.pos++;
}
nc.size(c);
}
return nc;
}
/**
* Extracts connection options.
*
* @param arg argument with options
* @param root expected root element
* @param ctx query context
* @return options
* @throws QueryException query exception
*/
private TokenObjMap<Object> options(final int arg, final QNm root, final QueryContext ctx)
throws QueryException {
// initialize token map
final TokenObjMap<Object> tm = new TokenObjMap<Object>();
// argument does not exist...
if (arg >= expr.length) return tm;
// empty sequence...
final Item it = expr[arg].item(ctx, input);
if (it == null) return tm;
// XQuery map: convert to internal map
if (it instanceof Map) return ((Map) it).tokenJavaMap(input);
// no element: convert XQuery map to internal map
if (!it.type().eq(SeqType.ELM)) throw NODFUNTYPE.thrw(input, this, it.type);
// parse nodes
ANode node = (ANode) it;
if (!node.qname().eq(root)) PARWHICH.thrw(input, node.qname());
// interpret query parameters
final AxisIter ai = node.children();
while ((node = ai.next()) != null) {
final QNm qn = node.qname();
if (!qn.uri().eq(Uri.uri(SQLURI))) PARWHICH.thrw(input, qn);
tm.add(qn.ln(), node.children().next());
}
return tm;
}
/**
* Returns the value of the specified attribute, or {@code null}.
*
* @param name attribute to be found
* @return attribute value
*/
public byte[] attribute(final QNm name) {
final AxisIter ai = attributes();
while (true) {
final ANode node = ai.next();
if (node == null) return null;
if (node.qname().eq(name)) return node.atom();
}
}
/**
* Removes unused namespaces.
*
* @param node to be modified
*/
private static void noPreserve(final ANode node) {
final Atts ns = node.namespaces();
final byte[] pref = node.qname().prefix();
for (int i = ns.size() - 1; i >= 0; i--) {
boolean f = eq(ns.name(i), pref);
final AxisIter atts = node.attributes();
for (ANode it; f && (it = atts.next()) != null; ) {
f |= eq(it.qname().prefix(), pref);
}
if (!f) ns.delete(i);
}
}
/**
* Sets the parameters of a prepared statement.
*
* @param params parameters
* @param stmt prepared statement
* @throws QueryException query exception
*/
private void setParameters(final AxisMoreIter params, final PreparedStatement stmt)
throws QueryException {
int i = 0;
for (ANode next; (next = params.next()) != null; ) {
// Check name
if (!next.qname().eq(E_PARAM)) PARWHICH.thrw(input, next.qname());
final AxisIter attrs = next.attributes();
byte[] paramType = null;
boolean isNull = false;
for (ANode attr; (attr = attrs.next()) != null; ) {
// Attribute "type"
if (eq(attr.nname(), TYPE)) paramType = attr.atom();
// Attribute "null"
else if (eq(attr.nname(), NULL))
isNull = attr.atom() != null && Bln.parse(attr.atom(), input);
// Not expected attribute
else throw NOTEXPATTR.thrw(input, string(attr.nname()));
}
if (paramType == null) NOPARAMTYPE.thrw(input);
final byte[] v = next.atom();
isNull |= v.length == 0;
setParam(++i, stmt, paramType, isNull ? null : string(v), isNull);
}
}
/**
* Counts the numbers of <sql:parameter/> elements.
*
* @param params element <sql:parameter/>
* @return number of parameters
*/
private long countParams(final ANode params) {
final AxisIter ch = params.children();
long c = ch.size();
if (c == -1) do ++c; while (ch.next() != null);
return c;
}
