C#•14mo ago

❔ Does System.Text.Json.JsonSerializer allow members to be serialized or do I need properties?

The problem is that my properties commonly have set accessors that do things like mark the item dirty. You can't have a property with both set and init, or am I misunderstanding something?

20 Replies

Will PittengerOP•14mo ago

For me, set is also firing off events. So what should I do?

Thinker•14mo ago

Your serialization DTO really shouldn't be firing events

Will PittengerOP•14mo ago

init would just set the field. Nothing else. Which is why I was trying to put the [JsonInclude] attribute on the field. But I'm getting an exception.

Thinker•14mo ago

no I mean you should ideally be deserializing your json to a separate dto type which you then create your actual entity/model/whatever from anyway what's the exception?

Will PittengerOP•14mo ago

The non-public property 'strName' on type 'BestChat.IRC.Data.Defs.Network' is annotated with 'JsonIncludeAttribute' which is invalid.'

Well, I'm looking into initializing from a JsonElement, but I don't see a good way to simply test if a property exists. I was hoping to do something like x = element.HasProperty(nameof(x)) ? element.GetProperty(nameof(x)) : default;. I can't use an enumerator as some fields might be missing from the file and need to be explicitly defaulted before the constructor exits.

MODiX•14mo ago

Thinker

REPL Result: Success

record PersonDto(string Name, int Age);

class Person
{
    private string _name;
    private int _age;

    public string Name
    {
        get => _name;
        set
        {
            Console.WriteLine("set name");
            _name = value;
        }
    }

    public int Age
    {
        get => _age;
        set
        {
            Console.WriteLine("set age");
            _age = value;
        }
    }

    public Person(PersonDto dto) => (_name, _age) = (dto.Name, dto.Age);
}

var json = """{"Name":"John Doe","Age":41}""";

var dto = System.Text.Json.JsonSerializer.Deserialize<PersonDto>(json);
var person = new Person(dto);

person.Age = 42;

Console.WriteLine($"Name: {person.Name}, Age: {person.Age}");

record PersonDto(string Name, int Age);

class Person
{
    private string _name;
    private int _age;

    public string Name
    {
        get => _name;
        set
        {
            Console.WriteLine("set name");
            _name = value;
        }
    }

    public int Age
    {
        get => _age;
        set
        {
            Console.WriteLine("set age");
            _age = value;
        }
    }

    public Person(PersonDto dto) => (_name, _age) = (dto.Name, dto.Age);
}

var json = """{"Name":"John Doe","Age":41}""";

var dto = System.Text.Json.JsonSerializer.Deserialize<PersonDto>(json);
var person = new Person(dto);

person.Age = 42;

Console.WriteLine($"Name: {person.Name}, Age: {person.Age}");

Console Output

set age
Name: John Doe, Age: 42

set age
Name: John Doe, Age: 42

Compile: 812.406ms | Execution: 176.700ms | React with ❌ to remove this embed.

Thinker•14mo ago

is there a reason you can't do something akin to this?

Will PittengerOP•14mo ago

Don't know. Looks like I have no place with that simple syntax to use [JsonRequired].

Thinker•14mo ago

record Person([property: JsonRequired] string Name, int Age);

record Person([property: JsonRequired] string Name, int Age);

Will PittengerOP•14mo ago

Does putting a default on that have an effect?

record Person(string Name, int Age =3);

record Person(string Name, int Age =3);

Thinker•14mo ago

yeah, if you don't provide a value then it'll use that value by default

MODiX•14mo ago

Thinker

REPL Result: Success

record Person(string Name, int Age = 3);

var json = """{"Name":"John Doe"}""";

System.Text.Json.JsonSerializer.Deserialize<Person>(json)

record Person(string Name, int Age = 3);

var json = """{"Name":"John Doe"}""";

System.Text.Json.JsonSerializer.Deserialize<Person>(json)

Result: Person

{
  "name": "John Doe",
  "age": 3
}

{
  "name": "John Doe",
  "age": 3
}

Compile: 647.087ms | Execution: 86.095ms | React with ❌ to remove this embed.

Will PittengerOP•14mo ago

Is the serializer supposed to convert enums for you? The value matches a value from the enum type for a field, but it's throwing an exception. Though it's reporting the line before the enum value.

Thinker•14mo ago

Is the enum value in the json a string or number?

Will PittengerOP•14mo ago

string.

Thinker•14mo ago

In that case you'll have to add a JsonStringEnumConverter to the converter in the json settings Or if you're using .NET 8 then you can use the generic version JsonStringEnumConverter<YourEnum>

Will PittengerOP•14mo ago

I don't see a JsonStringEnumConverter. Is .NET 8 out?

Thinker•14mo ago

System.Text.Json.Serialization.JsonStringEnumConverter Comes out in November but release candidate 1 is out

Will PittengerOP•14mo ago

OK. Well, now it thinks some required properties are missing. I don't think they are missing. I took out the [JsonRequired] for the moment so I could get it up. Seems to work that way. I don't understand why it thought it the required fields were missing. It filled them just fine.

Accord•14mo ago

Was this issue resolved? If so, run /close - otherwise I will mark this as stale and this post will be archived until there is new activity.

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❔ Does System.Text.Json.JsonSerializer allow members to be serialized or do I need properties?