/// <summary>Tries to create a key segment for the given filter if it is non empty.</summary>
/// <param name="previous">Segment on which to compose.</param>
/// <param name="filter">Filter portion of segment, possibly null.</param>
/// <param name="keySegment">The key segment that was created if the key was non-empty.</param>
/// <returns>Whether the key was non-empty.</returns>
internal static bool TryCreateKeySegmentFromParentheses(IPathSegment previous, string filter, out IPathSegment keySegment)
{
DebugUtils.CheckNoExternalCallers();
Debug.Assert(filter != null, "filter != null");
Debug.Assert(previous != null, "segment!= null");
WebUtil.CheckSyntaxValid(!previous.SingleResult);
KeyInstance key;
WebUtil.CheckSyntaxValid(KeyInstance.TryParseKeysFromUri(filter, out key));
if (key.IsEmpty)
{
keySegment = null;
return(false);
}
keySegment = CreateKeySegment(previous, key);
return(true);
}
