Is this still the way to handle JSON serializer circular reference exception in asp.net MVC

Question

I'm using MVC5 and Visual Studio 2013 with entity framework. Basic problem is when we have a many-to-many relationships like this:

public class Person
{
    public int ID { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public ICollection<Group> Groups { get; set; }

    public Patient()
    {
        Groups = new HashSet<Group>();
    }
}
public class Group
{
    public Guid ID { get; set; }
    public string Name { get; set; }

    public ICollection<Person> People{ get; set; }

    public Group()
    {
        People = new HashSet<Person>();
    }
}

and we want to get the JSON representation for a record like this

 Person person = db.People.Include(x => x.Groups).Where(i => i.ID == id).Single();
string json=JsonConvert.SerializeObject(person);

the JsonConvert throws a circular reference exception.

This SO question has an easy solution by configuring it to ignore circular reference exceptions:

var serializerSettings = new JsonSerializerSettings { PreserveReferencesHandling = PreserveReferencesHandling.Objects };
string json=JsonConvert.SerializeObject(person,serializerSettings);

My question is this: is this still the best way to deal with this situation? Those SO answers are now very old, and this seems like a very common situation. I've updated everything I can think of to update in my solution, but I still get the exception unless I do the extra configuration step.

Also, are there side effects to setting PreserveReferencesHandling = PreserveReferencesHandling.Objects? Is there any reason ever not do this?

score 0 · Answer 1 · answered Jan 15 '16 at 16:52

using datamembers is a better solution I think. Here you can chose what to serialize and what not.

Not adding attributes to the unwanted/circular references solves the problem of the circular serialization.

http://www.newtonsoft.com/json/help/html/DataContractAndDataMember.htm

score 0 · Answer 2 · answered Jan 15 '16 at 17:24

0

Another way is to avoid eager loading, by removing include extension method from your statement. Or create another custom class for your dependent object and use projection using select(x => new CustomClass {PropertyOne = p.PropertyOne})

answered Jan 15 '16 at 17:24

Kopadze

31
4

score 0 · Answer 3 · answered Jan 15 '16 at 20:43

You just need to add [ScriptIgnore(ApplyToOverrides = true)] into your text template (.tt) file (part of the EF data model).

Here a portion of my text template before

#>
<#=codeStringGenerator.NavigationProperty(navigationProperty)#>
<#

Once I inserted the code the line above the codeStringGenerator my classes auto generated and looked like this:

[ScriptIgnore(ApplyToOverrides = true)]
public virtual ICollection<Currency> Currencies { get; set; }

I also needed to modify the UsingDirectives function to insert "using System.Web.Script.Serialization;"

Is this still the way to handle JSON serializer circular reference exception in asp.net MVC

3 Answers3