JoinNode.cs

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// 
//  Copyright 2010-2015 Deveel
// 
//    Licensed under the Apache License, Version 2.0 (the "License");
//    you may not use this file except in compliance with the License.
//    You may obtain a copy of the License at
// 
//        http://www.apache.org/licenses/LICENSE-2.0
// 
//    Unless required by applicable law or agreed to in writing, software
//    distributed under the License is distributed on an "AS IS" BASIS,
//    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//    See the License for the specific language governing permissions and
//    limitations under the License.
//

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using Deveel.Data.Sql.Expressions;

namespace Deveel.Data.Sql.Parser {
    class JoinNode : SqlNode {
        internal JoinNode() {   
        }

        public IFromSourceNode Source { get; private set; }

        public IExpressionNode OnExpression { get; private set; }

        public string JoinType { get; private set; }

        public JoinNode NextJoin { get; private set; }

        protected override ISqlNode OnChildNode(ISqlNode node) {
            if (node.NodeName == "join_type") {
                GetJoinType(node);
            } else if (node is IFromSourceNode) {
                Source = (IFromSourceNode) node;
            } else if (node.NodeName == "from_source") {
                Source = (IFromSourceNode) node.ChildNodes.FirstOrDefault();
            } else if (node.NodeName == "on_opt") {
                OnExpression = node.FindNode<IExpressionNode>();
            } else if (node.NodeName == "join_opt") {
                var join = node.ChildNodes.FirstOrDefault();
                if (join != null)
                    NextJoin = (JoinNode) join;
            }

            return base.OnChildNode(node);
        }

        private void GetJoinType(ISqlNode node) {
            var sb = new StringBuilder();
            bool first = true;
            foreach (var childNode in node.ChildNodes) {
                if (!first)
                    sb.Append(" ");

                sb.Append(childNode.NodeName);
                first = false;
            }

            JoinType = sb.ToString();
        }
    }
}