/// <summary>
/// Retrieves keys of changed entities (added or modified) since moment.
/// <param name="source">The DbSet of requested entities</param>
/// <param name="context">The <see cref="DbContext"/> Instance of you DBContext to be configured.</param>
/// <param name="sinceMoment">Time period after which you need to get added or changed data</param>
/// <returns>Filtered DbSet</returns>
/// </summary>
public static IQueryable <TSource> AddedOrChanged <TSource>(this IQueryable <TSource> source, DbContext context, DateTime sinceMoment) where TSource : class
{
var trackableEntities = DbContextExtention.GetTrackInfoRuntime(context.GetType());
if (trackableEntities != null && trackableEntities.ContainsKey(typeof(TSource)))
{
var trackData = trackableEntities[typeof(TSource)];
var propTrackDbSet = context.GetType().GetProperties().Where(v => v.Name == trackData.NameOfTrackDbSet).First();
var trackSet = propTrackDbSet.GetValue(context);
var entityKeys = context.Model.GetEntityTypes(typeof(TSource)).First().GetKeys();
Type trackType = trackData.TrackType;
var trackKeys = context.Model.GetEntityTypes(trackType).First().GetKeys();
Func <object, bool> findPredicate = (a) => {
var res = StateOfEntity.Modified.Equals(a.GetType().GetProperty("StateOwner").GetValue(a)) ||
StateOfEntity.Added.Equals(a.GetType().GetProperty("StateOwner").GetValue(a));
return(res && (DateTime)a.GetType().GetProperty("Date").GetValue(a) > sinceMoment);
};
Func <TSource, Dictionary <string, object> > innerKeySelector = (a) => {
Dictionary <string, object> keyVals = new Dictionary <string, object>();
foreach (var k in entityKeys)
{
foreach (var p in k.Properties)
{
keyVals.Add(p.Name, p.PropertyInfo.GetValue(a));
}
}
return(keyVals);
};
Func <object, Dictionary <string, object> > outerKeySelector = (a) => {
Dictionary <string, object> keyVals = new Dictionary <string, object>();
foreach (var k in trackKeys)
{
foreach (var p in k.Properties)
{
keyVals.Add(p.Name, p.PropertyInfo.GetValue(a));
}
}
return(keyVals);
};
Func <object, TSource, TSource> resultSelector = (a, b) => {
return(b);
};
var foundedData = (trackSet as IQueryable <object>).Where <object>(findPredicate);
return(foundedData
.Join <object, TSource, Dictionary <string, object>, TSource>(source, outerKeySelector, innerKeySelector, resultSelector, new KeyComparer()).AsQueryable <TSource>());
}
return(source);
}
/// <summary>
/// Retrieves keys of entities deleted since moment.
/// <param name="source">The DbSet of requested entities</param>
/// <param name="context">The <see cref="DbContext"/> Instance of you DBContext to be configured.</param>
/// <param name="sinceMoment">Time period after which you need to get deleted data</param>
/// <returns>Filtered DbSet</returns>
/// </summary>
public static IQueryable <TSource> Deleted <TSource>(this IQueryable <TSource> source, DbContext context, DateTime sinceMoment) where TSource : class
{
var trackableEntities = DbContextExtention.GetTrackInfoRuntime(context.GetType());
if (trackableEntities != null && trackableEntities.ContainsKey(typeof(TSource)))
{
var trackData = trackableEntities[typeof(TSource)];
var propTrackDbSet = context.GetType().GetProperties().Where(v => v.Name == trackData.NameOfTrackDbSet).First();
var trackSet = propTrackDbSet.GetValue(context);
Type trackType = trackData.TrackType;
Func <object, bool> findPredicate = (a) => {
var res = StateOfEntity.Deleted.Equals(a.GetType().GetProperty("StateOwner").GetValue(a));
return(res && (DateTime)a.GetType().GetProperty("Date").GetValue(a) > sinceMoment);
};
return((trackSet as IQueryable <object>).Where <object>(findPredicate).AsQueryable <object>().FromTrack <object, TSource>());
}
return(source);
}
/// <summary>
/// Create extention for track entity change.
/// </summary>
/// <param name="modelBuilder">The <see cref="ModelBuilder"/> to enable track and save entity change.</param>
/// <param name="contextType">The type of DbContext.</param>
/// <returns>The <see cref="ModelBuilder"/> had enabled track and save entity change feature.</returns>
public static ModelBuilder CreateDataChangeTracking(this ModelBuilder modelBuilder, Type contextType)
{
FieldInfo trackField = contextType.GetField("_isRuntimeConstructedForTrack", BindingFlags.Static | BindingFlags.NonPublic);
if (trackField != null)
{
var trackableEntities = DbContextExtention.GetTrackInfo(contextType);
if (trackableEntities != null)
{
foreach (var entityType in (Dictionary <Type, EntityPropsForTransfer>)trackableEntities)
{
modelBuilder.Entity(entityType.Value.TrackType).HasNoDiscriminator();
modelBuilder.Entity(entityType.Value.TrackType).HasKey(entityType.Value.Props.Keys.ToArray());
modelBuilder.Entity(entityType.Value.TrackType).Property("Date").HasValueGenerator <ValueGeneratorDataNow>();
modelBuilder.Entity(entityType.Value.TrackType).HasIndex("Date").IsUnique(false);
modelBuilder.Entity(entityType.Value.TrackType).HasIndex("StateOwner").IsUnique(false);
}
}
}
return(modelBuilder);
}
