/// <summary>
/// Determine whether an ElementCtor, AttributeCtor, or NamespaceDecl's namespace is already declared. If it is,
/// set the IsNamespaceInScope property to True. Otherwise, add the namespace to the set of in-scope namespaces if
/// addInScopeNmsp is True. Return false if the name is computed or is invalid.
/// </summary>
private bool CheckNamespaceInScope(QilBinary nd)
{
QilName ndName;
string prefix, ns, prefixExisting, nsExisting;
XPathNodeType nodeType;
switch (nd.NodeType)
{
case QilNodeType.ElementCtor:
case QilNodeType.AttributeCtor:
ndName = nd.Left as QilName;
if (ndName != null)
{
prefix = ndName.Prefix;
ns = ndName.NamespaceUri;
nodeType = (nd.NodeType == QilNodeType.ElementCtor) ? XPathNodeType.Element : XPathNodeType.Attribute;
break;
}
// Not a literal name, so return false
return(false);
default:
Debug.Assert(nd.NodeType == QilNodeType.NamespaceDecl);
prefix = (string)(QilLiteral)nd.Left;
ns = (string)(QilLiteral)nd.Right;
nodeType = XPathNodeType.Namespace;
break;
}
// Attribute with null namespace and xmlns:xml are always in-scope
if (nd.NodeType == QilNodeType.AttributeCtor && ns.Length == 0 ||
prefix == "xml" && ns == XmlReservedNs.NsXml)
{
XmlILConstructInfo.Write(nd).IsNamespaceInScope = true;
return(true);
}
// Don't process names that are invalid
if (!ValidateNames.ValidateName(prefix, string.Empty, ns, nodeType, ValidateNames.Flags.CheckPrefixMapping))
{
return(false);
}
// Atomize names
prefix = _nsmgr.NameTable.Add(prefix);
ns = _nsmgr.NameTable.Add(ns);
// Determine whether namespace is already in-scope
for (int iNmsp = 0; iNmsp < _cntNmsp; iNmsp++)
{
_nsmgr.GetNamespaceDeclaration(iNmsp, out prefixExisting, out nsExisting);
// If prefix is already declared,
if ((object)prefix == (object)prefixExisting)
{
// Then if the namespace is the same, this namespace is redundant
if ((object)ns == (object)nsExisting)
{
XmlILConstructInfo.Write(nd).IsNamespaceInScope = true;
}
// Else quit searching, because any further matching prefixes will be hidden (not in-scope)
Debug.Assert(nd.NodeType != QilNodeType.NamespaceDecl || !_nsmgr.HasNamespace(prefix) || _nsmgr.LookupNamespace(prefix) == ns,
"Compilers must ensure that namespace declarations do not conflict with the namespace used by the element constructor.");
break;
}
}
// If not in-scope, then add if it's allowed
if (_addInScopeNmsp)
{
_nsmgr.AddNamespace(prefix, ns);
_cntNmsp++;
}
return(true);
}