CODEWITHSUNDEEP
c#json.net
dudeinco
dudeinco

Reputation: 197

JSON.NET Deserialization is not triggering setter

I have a class that derives from a list, and no matter what I do, I cannot find where JSON.NET is setting the value. It appears to me that even properties marked are not firing.

I have set breakpoints at all the following areas:

public CartItem Add(int id, int numItems, CARTITEMTYPE type = CARTITEMTYPE.GENERIC)
    {
        var item = NewByType(type);
        item.ID = id;
        item.NumItems = numItems;
        return this.Add(item);
    }

    public new CartItem Add(CartItem item)
    {
        item.Parent = this;
        base.Add(item);
        return item;
    }

    public new void AddRange(IEnumerable<CartItem> items)
    {
        items.Any(f => { f.Parent = this; return true; });
        base.AddRange(items);
    }

    public new void InsertRange(int index, IEnumerable<CartItem> items)
    {
        items.Any(f => { f.Parent = this; return true; });
        base.InsertRange(index, items);
    }

    public new CartItem Insert(int index, CartItem item)
    {
        item.Parent = this;
        base.Insert(index,item);
        return item;
    }

But none of these have triggered a break when running deserialization.

The deserialization process is relatively straightforward, using this:

    public T GetJObject<T>(string cookieName, JsonSerializerSettings jset = null)
    {
        string cookieContent = Get(cookieName);
        return JsonConvert.DeserializeObject<T>(cookieContent, jset);
    }

And the converter class is also straightforward:

public class JsonCartConverter : JsonConverter
{
    public override bool CanConvert(Type objectType)
    {
        return typeof(CartItem).IsAssignableFrom(objectType);
    }

    public override bool CanWrite
    {
        get
        {
            return false;
        }
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        JObject obj = JObject.Load(reader);

        var type = obj["t"] != null ? (CARTITEMTYPE)obj["t"].Value<int>() : CARTITEMTYPE.GENERIC;
        var item = CartItems.NewByType(type);
        serializer.Populate(obj.CreateReader(), item);
        return item;
    }


    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {

    }
}

Even areas marked with JsonProperty in other classes are not being hit on deserialization.

[JsonProperty("c")]
    public CartItems Children
    {
        get
        {
            if (_Children == null) _Children = new CartItems();
            if (_Children.Parent == null) _Children.Parent = this;
            _Children.SiteID = SiteID;
            _Children.UserID = UserID;
            return _Children;
        }
        set
        {
            Children.Parent = this;
            Console.WriteLine("we set the parent");
            _Children = value;
        }
    }

So how does JSON.NET treat setters and lists? Obviously, neither are being hit? Can I force it to hit the setter logic?

EDIT: JSON

[{"t":1,"i":1,"n":4,"r":false,"c":[{"t":5,"i":2,"n":4,"r":false,"c":[]}]},{"t":1,"i":3,"n":4,"r":false,"c":[{"t":5,"i":4,"n":4,"r":false,"c":[{"t":4,"i":6,"n":14,"r":false,"c":[]}]},{"t":1,"i":5,"n":15,"r":false,"c":[]}]}]

Upvotes: 4

Views: 2638

Answers (1)

dudeinco
dudeinco

Reputation: 197

I have the answer for the way that it attaches the children in the CartItem class (last example in OP). It never calls the setter, because it is grabbing the class using the getter, then populating it from there. ...and of course, the parent of the child class must have the attribute [JsonIgnore] attached.

I'm still not sure how to intercept the populating of the class to set the parent of its children:

Public CartItems : List<CartItem>

on the deserialization to set the Parent property of the children, but this is one out of two answers.

Edit: The second issue was answered by dbc here:

Intercept list population to assign values in deserialization

Upvotes: 2

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