using System.Collections.Generic;

using System.Web.Hosting;

using SmartStore.Core.Data;

using SmartStore.Core.Infrastructure;

namespace SmartStore.Core

{

public interface IMergedData

{

bool MergedDataIgnore { get; set; }

Dictionary<string, object> MergedDataValues { get; }

}

public static class IMergedDataExtensions

{

public static T GetMergedDataValue<T>(this IMergedData mergedData, string key, T defaultValue)

{

if (mergedData.MergedDataValues == null)

return defaultValue;

if (mergedData.MergedDataIgnore)

return defaultValue;

if (mergedData is BaseEntity && HostingEnvironment.IsHosted)

{

// This is absolutely bad coding! But I don't see any alternatives.

// When the passed object is a (EF)-trackable entity,

// we cannot return the merged value while EF performs

// change detection, because entity properties could be set to modified,

// where in fact nothing has changed.

var dbContext = EngineContext.Current.Resolve<IDbContext>();

if (dbContext.IsDetectingChanges())

{

return defaultValue;

}

}

object value;

if (mergedData.MergedDataValues.TryGetValue(key, out value))

{

return (T)value;

}

return defaultValue;

}

}

}