Question

I have a model which contains a JSON string, and would like to keep the parsed JSON.NET object along for the ride to prevent unnecessary re-parsings.

For example

public class JsonData {
  public Guid Id { get; set; }
  public string Json { get; set; }
}

I’d like to keep a JObject in there, and if possible on Json string’s set re-parse it. I wouldn’t want to store it in the database. As I write this, though, it just feels wrong…

What’s a good way to carry an object which is the same ‘data’ (view?), just serialized on top of a model?

Answer 1

I’m not sure this is what you mean, but you can add the [NotMapped] annotation to properties on your POCO that you want to use only in code and not store in the database;

public class MyPoco {

    public Guid Id { get; set; }
    public string MyName { get; set; }

    [NotMapped]
    public string ThisObjectCachedAsJson { get; set; }

}

A more complete example for your Json cache needs, deviating from POCO land though;

public class MyPoco {

    private Guid _id;
    private string _myName;
    private string _jsonCache;

    public Guid Id { 
        get { return _id; } 
        set { _jsonCache = null; _id = value; }
    }

    public string MyName { 
        get { return _myName; } 
        set { _jsonCache = null; _myName = value; }
    }

    [NotMapped]
    public string ThisObjectCachedAsJson { 
        get { 
            if(_jsonCache == null) 
                _jsonCache = <generate json>; 
            return _jsonCache; 
        }
    }
}

You should be able to create a base class with the getter and just call a method there to set _jsonCache to null. That’ll keep your classes a bit cleaner.