How to overwrite the implementation of a property created automatically in a partial class (T4 EF)?

Question

I need to add some logic when setting property DateCreated.

Class is partial and created automatically by a T4 template.

public partial class GaAnalytic
{
    public int AnalyticId { get; set; }
    public System.DateTime DateCreated { get; set; }
}

I would like to know if is possible overwrite DateCreated implementation, or other possible solutions.

possible duplicate of [Override a virtual method in a partial class](http://stackoverflow.com/questions/17241122/override-a-virtual-method-in-a-partial-class) — Tarec, Jun 03 '14 at 09:07
Not sure if DataCreated property is virtual in my specific case — GibboK, Jun 03 '14 at 09:08
@GibboK if it is not virtual, I can't get how we could override it's implementation. — Christos, Jun 03 '14 at 09:09

score 2 · Accepted Answer · answered Jun 03 '14 at 09:27

You simply cannot override in strict sense of the C# keyword a property in the same class. But there are workarounds.

Just until recently EF did not support enumeration properties so I needed to map those as integers and expose to our application as enumeration so basically I did kind of 'override' the property by introducing another that converted from int to enum and back. For that unfortunately you need second name for the same value

//in generated partial
public DateTime DateCreatedDB { get; set; }

//in second file that contains your partial of that class 
public DateTime DateCreated
{
     get { // return converted DateCreatedDB }
     set { // set DateCreatedDB to unconveted value }
}

From database and EF point of view there is a DateCreatedDB column that is mapped and processed. On the other hand you in your application use DateCreated.

If you use interfaces for your data model then it is a little bit simpler as you can provide explicit implementation for your interface property that does the conversion.

The other thing that you can do is to modify T4 template it is a bit of hassle to do it right as tools are not given out of the box, but it is doable and code would be cleaner.

score 1 · Answer 2 · answered Jun 03 '14 at 09:15

1

You can overwrite using new keyword.

public class GaAnalyticEx : GaAnalytic
{
    public new System.DateTime DateCreated { get; set; }
}

answered Jun 03 '14 at 09:15

Anuraj

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No derived classes are mentioned. – Maarten Jun 03 '14 at 09:21
2

It's about **overwriting** a potentially existing property in the same class, not about **overridding** a potentially existing property in a base class. – Maarten Jun 03 '14 at 09:23

How to overwrite the implementation of a property created automatically in a partial class (T4 EF)?

2 Answers2