Our JsonObject derives from Dictionary<string, JsonValue>, where JsonValue is just a boxing class with a few typecasting operators for primitive types and JsonObject itself (so you can nest objects). Say you have a data class like this used for tags:

public class MyTag
{
    public string Name { get; set; }
    public double Value { get; set; }
    public bool Flag { get; set; }
} 

you can serialize by writing to / reading from the dictionary:

static public class MyTagExtensions
{
    static public JsonObject WriteJson(this MyTag tag)
    {
        return new JsonObject
        {
            { "Name", tag.Name },
            { "Value", tag.Value},
            { "Flag", tag.Flag }
        };
    }

    static public void ReadJson(this MyTag tag, JsonObject json)
    {
        tag.Name = json["Name"];
        tag.Value = json["Value"];
        tag.Flag = json["Flag"];
    }
} 

and handle the events:

void OnJsonSerializeTag(object sender, JsonSerializeTagEventArgs e)
{
    if (e.PropertyName == "Tag" && e.Tag is MyTag myTag)
    {
        e.Representation = myTag.WriteJson();
        e.Handled = true;
    }
}

void OnJsonDeserializeTag(object sender, JsonSerializeTagEventArgs e)
{
    if (e.PropertyName == "Tag" && e.Object is DiagramItem item)
    {
        var myTag = new MyTag();
        myTag.ReadJson(e.Representation);
        e.Tag = myTag;
        e.Handled = true;
    }
} 

and now you should see tags in this format in the file:

"tag":{"Name":"test","Value":0.5,"Flag":true} 

I think we implemented our JSON API very shortly before System.Text.Json became available in standard dotnet, we'll be migrating to the latter when time allows.

Regards,
Slavcho
Mindfusion

How do I handle more complex types in my DiagramItem tags. For instance, I have:

string[]
List<int>
Color
DateTime
List<string[]>
Enumerated types.

DavidL

Ok, I will hang on until then and see what the new version will do. Also, I forgot to say that I also have a TimeSpan in my DiagramItem tag.

DavidL

dotnet8+ assemblies from this build now serialize tags using JsonSerializer from System.Text.Json:

https://www.nuget.org/packages/MindFusion.Diagramming/7.1.2-beta1

That's not implemented in old 4.X framework build as System.Text.Json is not available out of the box for it. Let us know if you need it there and we could target it through nuget package (https://www.nuget.org/packages/system.text.json/).

Saving diagram to XML file now uses XmlSerializer for Tag values as well, in case someone wants to try that.

Regards,
Slavcho
Mindfusion

As usual I have been pulled off on to other issues. I hope to get back to this in a few days.
DavidL