AlwaysUpdate attribute for Entity Framework Code First POCO

Question

The entity framework will only save properties it detects has changed via its proxy classes. I have a situation where I want a property to always be saved no matter if it changed or not.

I wrote a blank attribute called AlwaysUpdate which I apply to the property. I then overrode SaveChanges to scan for these attributes and mark the field as Modified. Is this code all right?

public override int SaveChanges()
{
 var changeSet = ChangeTracker.Entries();
 if (changeSet != null)
 {
 foreach (var entry in changeSet.Where( c=> c.State == System.Data.EntityState.Modified ))
 {
 foreach (var prop in entry.Entity.GetType().GetProperties().Where(p => p.GetCustomAttributes(typeof(AlwaysUpdateAttribute), true).Count() > 0).Select( p => p.Name ))
 {
 if (entry.State == System.Data.EntityState.Added || entry.State == System.Data.EntityState.Unchanged) continue;
 // Try catch removes the errors for detached and unchanged items
 try
 {
 entry.Property(prop).IsModified = true;
 }
 catch { }
 }
 }
 }
 return base.SaveChanges();
}

Answer 1

• Instead of checking .Count() > 0 which needs to iterate over the IEnumerable you can just use .Any() which only checks if at least one item is contained in the IEnumerable

• you should extract the result of typeof(AlwaysUpdateAttribute) to a variable.

  Type desiredType = typeof(AlwaysUpdateAttribute);
  

• you can restrict the outer loop by adding the "continue condition" to the Where() method. For readability we will do this outside of the loop

  changeSet = changeSet.Where( c=> 
   c.State == System.Data.EntityState.Modified 
   && !(entry.State == System.Data.EntityState.Added 
   || entry.State == System.Data.EntityState.Unchanged) 
   ); 
  

• you shouldn't shorten any variable names -> prop should be propertyName

Refactoring

Implementing all above will lead to

public override int SaveChanges()
{
 var changeSet = ChangeTracker.Entries();
 if (changeSet != null)
 {
 changeSet = changeSet.Where( c=> 
 c.State == System.Data.EntityState.Modified 
 && !(entry.State == System.Data.EntityState.Added 
 || entry.State == System.Data.EntityState.Unchanged) 
 ); 
 Type desiredType = typeof(AlwaysUpdateAttribute);
 foreach (var entry in changeSet)
 {
 foreach (var propertyName in entry.Entity.GetType().GetProperties().Where(p => p.GetCustomAttributes(desiredType , true).Any()).Select( p => p.Name ))
 {
 // Try catch removes the errors for detached and unchanged items
 try
 {
 entry.Property(propertyName).IsModified = true;
 }
 catch { }
 }
 }
 }
 return base.SaveChanges();
}
 foreach (var entry in changeSet) 
 {
 foreach (var prop in entry.Entity.GetType().GetProperties().Where(p => p.GetCustomAttributes(desiredType , true).Any()).Select( p => p.Name ))
 {
 // Try catch removes the errors for detached and unchanged items
 try
 {
 entry.Property(prop).IsModified = true;
 }
 catch { }
 }