Transforming JSON before binding to an object in a .net core controller-CodePudding

I'm trying to bind the JSON, that's coming from a source I cannot control, to a custom class in a controller. The problem that I ran to is the fact that the array of values are sent in format [{'value': 'value1'}, [{'value':'value2'}]. I know that I can create an object that would have one field 'value' and the binding would work, but I want to avoid that and get all the values from the request bound to a string list.

I have this controller method

  public async Task<IActionResult> UploadData(List<DataModel> values)

And here's how I'd like the DataModel to look like.

public class DataModel
{
        public string? a{ get; set; }
        public List<string>? b{ get; set; }
}

And here's how the example of data

[{
    "a": "name",
    "b": [
        {
        "value": "one"
        }, 
        {
        "value": "two"
        }
    ]
}]

Is there a way to achieve this, preferably using an attriubte?

CodePudding user response：

Leave the binding object exactly as it should be to map from the source you can't control and just make a custom getter for the object that transforms it in a list like you want. Using automapper or other suggested third party libs will add an unnecessary layer of complexity.

public class DataModel
{
    public string? a { get; set; }
    public List<ObjectFromSource> b{  get; set; }
    [NonSerialized]
    public string getb()
    {
        //returns a string list
        return string.Join(",", b.Select(x => x.value));
    }
}
public class ObjectFromSource
{
    public string? value { get; set; }
}

then when you need the value around you just call

DataModel x = new DataModel();
x.getb();

CodePudding user response：

the simpliest way is to change the action input parameter type

public async Task<IActionResult> UploadData(JArray jArr) 
{
  List<DataModel> values = jArr.Select(ja => new DataModel { a = (string)ja["a"], 
                  b = ja["b"].Select(b => (string)b["value"]).ToList() }).ToList();

//your code

}

another way is to use a JsonConstructor

public class DataModel
{
    public string? a { get; set; }
    public List<string>? b { get; set; }

    [Newtonsoft.Json.JsonConstructor]
    public DataModel (JArray b)
    {
        this.b= b.Select(b => (string)b["value"]).ToList();
    }
    public DataModel() {}
}