AddExceptionDescriptionAction.cs

//
// AddExceptionDescriptionAction.cs
//
// Author:
//       Mike Krüger <mkrueger@xamarin.com>
//
// Copyright (c) 2013 Xamarin Inc. (http://xamarin.com)
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
using ICSharpCode.NRefactory.CSharp;
using System.Collections.Generic;
using ICSharpCode.NRefactory.Semantics;
using ICSharpCode.NRefactory.Xml;
using ICSharpCode.NRefactory.Documentation;

namespace ICSharpCode.NRefactory.CSharp.Refactoring
{
	[ContextAction("Add an exception description to the xml documentation",
	               Description = "Add an exception description to the xml documentation")]
	public class AddExceptionDescriptionAction : SpecializedCodeAction<ThrowStatement>
	{
		static AstNode SearchInsertionNode (AstNode entity)
		{
			AstNode result = entity;
			while (result != null && (result.Role == Roles.Comment || result.Role == Roles.NewLine || result.Role == Roles.Whitespace))
				result = result.NextSibling;
			return result;
		}

		protected override CodeAction GetAction (RefactoringContext context, ThrowStatement node)
		{
			var entity = node.GetParent<EntityDeclaration> ();
			if (entity == null)
				return null;
			var rr = context.Resolve (entity) as MemberResolveResult;
			if (rr == null || rr.IsError)
				return null;
			var expr = context.Resolve (node.Expression);
			if (expr == null || expr.IsError || expr.Type.GetDefinition () == null)
				return null;

			var docElement = XmlDocumentationElement.Get (rr.Member);
			if (docElement == null || docElement.Children.Count == 0)
				return null;
			foreach (var de in docElement.Children) {
				if (de.Name == "exception") {
					if (de.ReferencedEntity == expr.Type)
						return null;
				}
			}

			return new CodeAction (
				context.TranslateString ("Add exception to xml documentation"),
				script => {
					var startText = string.Format (" <exception cref=\"{0}\">", expr.Type.GetDefinition ().GetIdString ());
					var comment = new Comment (startText +"</exception>", CommentType.Documentation);
					script.InsertBefore (
						SearchInsertionNode (entity.FirstChild) ?? entity, 
						comment
					);
					script.Select (script.GetSegment (comment).Offset + ("///" + startText).Length, 0);
				},
				node
			);
		}
	}
}