CreateLocalVariableAction.cs

// 
// CreateLocalVariable.cs
//  
// Author:
//       Mike Krüger <mkrueger@novell.com>
// 
// Copyright (c) 2011 Novell, Inc (http://www.novell.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 System.Collections.Generic;

namespace ICSharpCode.NRefactory.CSharp.Refactoring
{
	[ContextAction("Create local variable", Description = "Creates a local variable for a undefined variable.")]
	public class CreateLocalVariableAction : CodeActionProvider
	{
		public override IEnumerable<CodeAction> GetActions(RefactoringContext context)
		{
			var identifier = context.GetNode<IdentifierExpression>();
			if (identifier == null) {
				yield break;
			}
			if (CreateFieldAction.IsInvocationTarget(identifier)) {
				yield break;
			}
			var statement = context.GetNode<Statement>();
			if (statement == null) {
				yield break;
			}

			if (!(context.Resolve(identifier).IsError)) {
				yield break;
			}
			var guessedType = TypeGuessing.GuessAstType(context, identifier);
			if (guessedType == null) {
				yield break;
			}

			yield return new CodeAction(context.TranslateString("Create local variable"), script => {
				var initializer = new VariableInitializer(identifier.Identifier);
				var decl = new VariableDeclarationStatement() {
					Type = guessedType,
					Variables = { initializer }
				};
				if (identifier.Parent is AssignmentExpression && ((AssignmentExpression)identifier.Parent).Left == identifier) {
					initializer.Initializer = ((AssignmentExpression)identifier.Parent).Right.Clone();
					if (!context.UseExplicitTypes)
						decl.Type = new SimpleType("var");
					script.Replace(statement, decl);
				} else {
					script.InsertBefore(statement, decl);
				}
			}, identifier) { Severity = ICSharpCode.NRefactory.Refactoring.Severity.Error };
		}
	}
}