RuleBasedTransactionAttribute.cs :  » Inversion-of-Control-Dependency-Injection » Spring.net » Spring » Transaction » Interceptor » C# / CSharp Open Source

#region License

/*
 * Copyright 2002-2004 the original author or authors.
 *
 * 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.
 */

#endregion

using System;
using System.Collections;
using System.Text;

using Spring.Collections;

namespace Spring.Transaction.Interceptor{
  /// <summary>
  /// <see cref="Spring.Transaction.Interceptor.ITransactionAttribute"/> implementation
  /// that works out whether a given exception should cause transaction rollback by applying
  /// a number of rollback rules, both positive and negative.
  /// </summary>
  /// <remarks>
  /// If no rules are relevant to the exception, it behaves like the 
  /// <see cref="Spring.Transaction.Interceptor.DefaultTransactionAttribute"/> class
  /// (rolling back on runtime exceptions)..
  /// <p>
  /// The <see cref="Spring.Transaction.Interceptor.TransactionAttributeEditor"/> 
  /// creates objects of this class.
  /// </p>
  /// </remarks>
  /// <author>Rod Johnson</author>
  /// <author>Griffin Caprio (.NET)</author>
  public class RuleBasedTransactionAttribute : DefaultTransactionAttribute
  {
    private IList _rollbackRules;

    /// <summary>
    /// Creates a new instance of the
    /// <see cref="Spring.Transaction.Interceptor.RuleBasedTransactionAttribute"/>
    /// class.
    /// </summary>
    /// <param name="transactionPropagation">
    /// The desired transaction propagation behaviour.
    /// </param>
    /// <param name="ruleList">
    /// The rollback rules list for this transaction attribute.
    /// </param>
    public RuleBasedTransactionAttribute(
      TransactionPropagation transactionPropagation, IList ruleList )
      : base(transactionPropagation)
    {
      _rollbackRules = ruleList;
    }

    /// <summary>
    /// Creates a new instance of the
    /// <see cref="Spring.Transaction.Interceptor.RuleBasedTransactionAttribute"/>
    /// class.
    /// </summary>
    public RuleBasedTransactionAttribute( )
    {
      _rollbackRules = new ArrayList();
    }

    /// <summary>
    /// Sets the rollback rules list for this transaction attribute.
    /// </summary>
    public IList RollbackRules
    {
      set { _rollbackRules = value; }
    }

    /// <summary>
    /// Will a transaction be rolled back if the supplied <parameref name="exception"/>
    /// is thrown during the lifecycle of a transaction to which this attribute is applied?
    /// </summary>
    /// <param name="exception">The offending <see cref="System.Exception"/>.</param>
    /// <returns>True if the exception should cause a rollback, false otherwise.</returns>
    public override bool RollbackOn(Exception exception)
    {
      RollbackRuleAttribute finalAttribute = null;
      int deepest = Int32.MaxValue;

      if ( _rollbackRules != null )
      {
        foreach ( RollbackRuleAttribute rule in _rollbackRules )
        {
          int depth = rule.GetDepth( exception );
          if ( ( depth >= 0 ) && ( depth < deepest ) )
          {
            deepest = depth;
            finalAttribute = rule;
          }
        }
      }
      if ( null == finalAttribute )
      {
        return base.RollbackOn( exception );
      }
      return !( finalAttribute is NoRollbackRuleAttribute );
    }

    /// <summary>
    /// Returns a <see cref="System.String"/> representation of this instance.
    /// </summary>
    /// <returns>
    /// A <see cref="System.String"/> representation of this instance.
    /// </returns>
    public override string ToString()
    {
      StringBuilder result = new StringBuilder();
      result.Append(DefinitionDescription);
      SortedSet rules = new SortedSet();
      foreach ( RollbackRuleAttribute rule in _rollbackRules )
      {
        string sign = ( rule is NoRollbackRuleAttribute ) ? COMMIT_RULE_PREFIX : ROLLBACK_RULE_PREFIX;
        rules.Add( sign + rule.ExceptionName );
      }
      foreach ( string rule in rules )
      {
        result.Append(',');
        result.Append(rule);
      }
      return result.ToString( );
    }
    /// <summary>
    /// Adds a <see cref="Spring.Transaction.Interceptor.RollbackRuleAttribute"/> to this
    /// attributes list of rollback rules.
    /// </summary>
    /// <param name="rule">
    /// The <see cref="Spring.Transaction.Interceptor.RollbackRuleAttribute"/> to add.
    /// </param>
    public void AddRollbackRule( RollbackRuleAttribute rule )
    {
      _rollbackRules.Add( rule );
    }

    /// <summary>
    /// Clears the rollback rules for this attribute.
    /// </summary>
    public void ClearRollbackRules()
    {
      _rollbackRules.Clear();
    }
  }
}