A wrapper for IAtomicWriter (see Lokad.CQRS.Sample) that calls a provided action after successful updates/deletes

gistfile1.cs

internal class PublishingAtomicWriter<TKey, TEntity> : IAtomicWriter<TKey, TEntity> where TEntity : class
{
    private readonly IClientNotificationService _clients;
    private readonly IAtomicWriter<TKey, TEntity> _writer;
    private readonly Action<TKey, TEntity> _publishAction;

    public PublishingAtomicWriter(IAtomicWriter<TKey, TEntity> writer, Action<TKey, TEntity> publishAction)
    {
        if (publishAction == null) throw new ArgumentNullException("publishAction");

        _writer = writer;
        _publishAction = publishAction;
    }

    public TEntity AddOrUpdate(TKey key, Func<TEntity> addFactory, Func<TEntity, TEntity> update, AddOrUpdateHint hint = AddOrUpdateHint.ProbablyExists)
    {
        var entity = _writer.AddOrUpdate(key, addFactory, update, hint);
        
        if(entity != null)
            _publishAction(key, entity);
        
        return entity;
    }

    public bool TryDelete(TKey key)
    {
        var success = _writer.TryDelete(key);
        
        if(success)
            _publishAction(key, null);

        return success;
    }
}