/// <summary> translate an xpath path reference into a TreeReference
/// TreeReferences only support a subset of true xpath paths; restrictions are:
/// simple child name tests 'child::name', '.', and '..' allowed only
/// no predicates
/// all '..' steps must come before anything else
/// </summary>
public virtual TreeReference getReference(bool allowPredicates)
{
TreeReference ref_Renamed = new TreeReference();
bool parentsAllowed;
switch (init_context)
{
case XPathPathExpr.INIT_CONTEXT_ROOT:
ref_Renamed.RefLevel = TreeReference.REF_ABSOLUTE;
parentsAllowed = false;
break;
case XPathPathExpr.INIT_CONTEXT_RELATIVE:
ref_Renamed.RefLevel = 0;
parentsAllowed = true;
break;
case XPathPathExpr.INIT_CONTEXT_EXPR:
if (this.filtExpr.x != null && this.filtExpr.x is XPathFuncExpr)
{
XPathFuncExpr func = (XPathFuncExpr)(this.filtExpr.x);
if (func.id.ToString().Equals("instance"))
{
ref_Renamed.RefLevel = TreeReference.REF_ABSOLUTE; //i assume when refering the non main instance you have to be absolute
parentsAllowed = false;
if (func.args.Length != 1)
{
throw new XPathUnsupportedException("instance() function used with " + func.args.Length + " arguements. Expecting 1 arguement");
}
if (!(func.args[0] is XPathStringLiteral))
{
throw new XPathUnsupportedException("instance() function expecting 1 string literal arguement arguement");
}
XPathStringLiteral strLit = (XPathStringLiteral)(func.args[0]);
//we've got a non-standard instance in play, watch out
if (strLit.s == null)
{
// absolute reference to the main instance
ref_Renamed.Context = TreeReference.CONTEXT_ABSOLUTE;
ref_Renamed.InstanceName = null;
}
else
{
ref_Renamed.Context = TreeReference.CONTEXT_INSTANCE;
ref_Renamed.InstanceName = strLit.s;
}
}
else
{
if (func.id.ToString().Equals("current"))
{
parentsAllowed = true;
ref_Renamed.Context = TreeReference.CONTEXT_ORIGINAL;
}
else
{
//We only support expression root contexts for instance refs, everything else is an illegal filter
throw new XPathUnsupportedException("filter expression");
}
}
}
else
{
//We only support expression root contexts for instance refs, everything else is an illegal filter
throw new XPathUnsupportedException("filter expression");
}
break;
default: throw new XPathUnsupportedException("filter expression");
}
for (int i = 0; i < steps.Length; i++)
{
XPathStep step = steps[i];
if (step.axis == XPathStep.AXIS_SELF)
{
if (step.test != XPathStep.TEST_TYPE_NODE)
{
throw new XPathUnsupportedException("step other than 'child::name', '.', '..'");
}
}
else if (step.axis == XPathStep.AXIS_PARENT)
{
if (!parentsAllowed || step.test != XPathStep.TEST_TYPE_NODE)
{
throw new XPathUnsupportedException("step other than 'child::name', '.', '..'");
}
else
{
ref_Renamed.incrementRefLevel();
}
}
else if (step.axis == XPathStep.AXIS_ATTRIBUTE)
{
if (step.test == XPathStep.TEST_NAME)
{
ref_Renamed.add(step.name.ToString(), TreeReference.INDEX_ATTRIBUTE);
parentsAllowed = false;
//TODO: Can you step back from an attribute, or should this always be
//the last step?
}
else
{
throw new XPathUnsupportedException("attribute step other than 'attribute::name");
}
}
else if (step.axis == XPathStep.AXIS_CHILD)
{
if (step.test == XPathStep.TEST_NAME)
{
ref_Renamed.add(step.name.ToString(), TreeReference.INDEX_UNBOUND);
parentsAllowed = true;
}
else if (step.test == XPathStep.TEST_NAME_WILDCARD)
{
ref_Renamed.add(TreeReference.NAME_WILDCARD, TreeReference.INDEX_UNBOUND);
parentsAllowed = true;
}
else
{
throw new XPathUnsupportedException("step other than 'child::name', '.', '..'");
}
}
else
{
throw new XPathUnsupportedException("step other than 'child::name', '.', '..'");
}
if (step.predicates.Length > 0)
{
int refLevel = ref_Renamed.RefLevel;
List <XPathExpression> v = new List <XPathExpression>();
for (int j = 0; j < step.predicates.Length; j++)
{
v.addElement(step.predicates[j]);
}
ref_Renamed.addPredicate(i, v);
}
}
return(ref_Renamed);
}