public LocationStep(string exp)
{
if (exp.IndexOf("::") > 0)
{
int start = exp.IndexOf("::");
string axisSpec = exp.Substring(0, start);
exp = exp.Substring(start + 2);
this._axis = AxisSpecifier.Find(axisSpec);
}
else
{
if (exp[0] == '@')
{
this._axis = AxisSpecifier.Attribute;
exp = exp.Substring(1);
}
else if (exp.Length >= 2 && exp.Substring(0, 2).Equals(".."))
{
this._axis = AxisSpecifier.Parent;
}
else if (exp[0] == '.')
{
this._axis = AxisSpecifier.Self;
}
else
{
this._axis = AxisSpecifier.Child;
}
}
this._predicates = new List <Predicate>();
MatchCollection matches = predicateMatcher.Matches(exp);
if (matches.Count > 0)
{
foreach (Match match in matches)
{
this._predicates.Add(new Predicate(match.Value));
}
exp = exp.Substring(0, matches[0].Index);
}
if (this._axis == AxisSpecifier.Parent)
{
this._nodeTest = NodeTest.Create("*");
}
else
{
this._nodeTest = NodeTest.Create(exp);
}
}
/// <summary>
/// Creates the standard AxisSpecifiers. This is all done privately and statically because the AxisSpecifiers
/// are standardized to only certain values (see documentation at top of file).
/// </summary>
static AxisSpecifier()
{
AllSpecifiers = new List <AxisSpecifier>();
Child = new AxisSpecifier(PrincipalNodeTypes.Element, "child", "");
Attribute = new AxisSpecifier(PrincipalNodeTypes.Attribute, "attribute", "@");
Descendant = new AxisSpecifier(PrincipalNodeTypes.Element, "descendant", "/");
DescendantOrSelf = new AxisSpecifier(PrincipalNodeTypes.Element, "descendant-or-self", null);
Parent = new AxisSpecifier(PrincipalNodeTypes.Element, "parent", "..");
Ancestor = new AxisSpecifier(PrincipalNodeTypes.Element, "ancestor", null);
AncestorOrSelf = new AxisSpecifier(PrincipalNodeTypes.Element, "ancestor-or-self", null);
Following = new AxisSpecifier(PrincipalNodeTypes.Element, "following", null);
Preceding = new AxisSpecifier(PrincipalNodeTypes.Element, "preceding", null);
FollowingSibling = new AxisSpecifier(PrincipalNodeTypes.Element, "following-sibling", null);
PrecedingSibling = new AxisSpecifier(PrincipalNodeTypes.Element, "preceding-sibling", null);
Self = new AxisSpecifier(PrincipalNodeTypes.Element, "self", ".");
Namespace = new AxisSpecifier(PrincipalNodeTypes.Namespace, "namespace", null);
}
/// <summary>
/// Creates a new Location Step for a provided axis type and node test
/// </summary>
/// <param name="axis"></param>
/// <param name="nodeTest"></param>
public LocationStep(AxisSpecifier axis, NodeTest nodeTest)
{
this._axis = axis;
this._nodeTest = nodeTest;
this._predicates = new List <Predicate>();
}