/// <summary>
/// Combines two <see cref="AlternatesCollection"/>.
/// </summary>
/// <remarks>
/// First and second can be null.
/// </remarks>
/// <param name="first">First collection.</param>
/// <param name="second">Second collection.</param>
/// <returns>Combined <see cref="AlternatesCollection"/>.</returns>
public static AlternatesCollection Combine(this AlternatesCollection first, AlternatesCollection second)
{
if (first == null)
{
return(second);
}
else if (second != null)
{
first.AddRange(second);
}
return(first);
}
private async Task <ShapeBinding> GetShapeBindingAsync(string shapeType, AlternatesCollection shapeAlternates, ShapeTable shapeTable)
{
// shape alternates are optional, fully qualified binding names
// the earliest added alternates have the lowest priority
// the descriptor returned is based on the binding that is matched, so it may be an entirely
// different descriptor if the alternate has a different base name
for (var i = shapeAlternates.Count - 1; i >= 0; i--)
{
var shapeAlternate = shapeAlternates[i];
foreach (var shapeBindingResolver in _shapeBindingResolvers)
{
var binding = await shapeBindingResolver.GetShapeBindingAsync(shapeAlternate);
if (binding != null)
{
return(binding);
}
}
if (shapeTable.Bindings.TryGetValue(shapeAlternate, out var shapeBinding))
{
return(shapeBinding);
}
}
// when no alternates match, the shapeType is used to find the longest matching binding
// the shapetype name can break itself into shorter fallbacks at double-underscore marks
// so the shapetype itself may contain a longer alternate forms that falls back to a shorter one
var shapeTypeScan = shapeType;
do
{
foreach (var shapeBindingResolver in _shapeBindingResolvers)
{
var binding = await shapeBindingResolver.GetShapeBindingAsync(shapeTypeScan);
if (binding != null)
{
return(binding);
}
}
if (shapeTable.Bindings.TryGetValue(shapeTypeScan, out var shapeBinding))
{
return(shapeBinding);
}
}while (TryGetParentShapeTypeName(ref shapeTypeScan));
return(null);
}
