/// <summary>
/// Returns a selector which matches a type or a derived type.
/// </summary>
/// <typeparam name="T">The type.</typeparam>
/// <param name="previous">The previous selector.</param>
/// <returns>The selector.</returns>
public static Selector Is <T>(this Selector previous) where T : IStyleable
{
return(previous.Is(typeof(T)));
}
/// <summary>
/// Parses a <see cref="Selector"/> from a string.
/// </summary>
/// <param name="s">The string.</param>
/// <returns>The parsed selector.</returns>
public Selector Parse(string s)
{
var syntax = SelectorGrammar.Selector.Parse(s);
var result = new Selector();
foreach (var i in syntax)
{
var ofType = i as SelectorGrammar.OfTypeSyntax;
var @is = i as SelectorGrammar.IsSyntax;
var @class = i as SelectorGrammar.ClassSyntax;
var name = i as SelectorGrammar.NameSyntax;
var property = i as SelectorGrammar.PropertySyntax;
var child = i as SelectorGrammar.ChildSyntax;
var descendent = i as SelectorGrammar.DescendentSyntax;
var template = i as SelectorGrammar.TemplateSyntax;
if (ofType != null)
{
result = result.OfType(_typeResolver(ofType.TypeName, ofType.Xmlns));
}
if (@is != null)
{
result = result.Is(_typeResolver(@is.TypeName, @is.Xmlns));
}
else if (@class != null)
{
result = result.Class(@class.Class);
}
else if (name != null)
{
result = result.Name(name.Name);
}
else if (property != null)
{
var type = result.TargetType;
if (type == null)
{
throw new InvalidOperationException("Property selectors must be applied to a type.");
}
var targetProperty = PerspexPropertyRegistry.Instance.FindRegistered(type, property.Property);
if (targetProperty == null)
{
throw new InvalidOperationException($"Cannot find '{property.Property}' on '{type}");
}
object typedValue;
if (TypeUtilities.TryConvert(
targetProperty.PropertyType,
property.Value,
CultureInfo.InvariantCulture,
out typedValue))
{
result = result.PropertyEquals(targetProperty, typedValue);
}
else
{
throw new InvalidOperationException(
$"Could not convert '{property.Value}' to '{targetProperty.PropertyType}");
}
}
else if (child != null)
{
result = result.Child();
}
else if (descendent != null)
{
result = result.Descendent();
}
else if (template != null)
{
result = result.Template();
}
}
return result;
}