Return JSON from API method

Question

I am using ASP.net Core web api (c#) here

I have a JSON string as:

{
   "userId":321,   
   "account":"new  
   "fname":"Adam",
   "lname":"Silver" 
   "features":[
      {
         "available":true,
         "status":open,
         "admin":false        
      }
   ]
}

I want to test this data in my angular code so wanted to hardcode this into my API; then I want my API to return this back. What I am finding it hard is how to return this. Shall I return this as a string or need to parse it?

I have this method in my API:

[HttpGet]        
public ActionResult<IEnumerable<string>> Get()
{
     return new string[] { "value1", "value2" };
}

Do I need to represent this into string or parse it someway?

Answer 1

Hi Please find correct JSON format for above one:

{
    "userId": 321,
    "account": "new",
    "fname": "Adam",
    "lname": "Silver",
    "features": [{
        "available": true,
        "status": "open",
        "admin": false
    }]
}

you can use below class in your web API to pass respective data

public class Feature
{
    public bool available { get; set; }
    public string status { get; set; }
    public bool admin { get; set; }
}

public class RootObject
{
    public int userId { get; set; }
    public string account { get; set; }
    public string fname { get; set; }
    public string lname { get; set; }
    public List<Feature> features { get; set; }
}

then at the end, while returning data, convert the respective class object into JSON by serializing that into JSON format.

Hope it will fulfill your requirement.

Answer 2

Your JSON is invalid. We need to correct it. JSONLint can be helpful for that. I took your JSON and corrected the syntax errors until I got this:

{
   "userId": 321,   
   "account": "new",
   "fname": "Adam",
   "lname": "Silver",
   "features":[
      {
         "available": true,
         "status": "open",
         "admin": false        
      }
   ]
}

Then I need to generate a C# class structure to represent this JSON. I could manually create it, but the excellent json2csharp.com can generate it for me quickly. I fed this JSON into and received the following classes back:

public class Feature
{
    public bool available { get; set; }
    public string status { get; set; }
    public bool admin { get; set; }
}

public class RootObject
{
    public int userId { get; set; }
    public string account { get; set; }
    public string fname { get; set; }
    public string lname { get; set; }
    public List<Feature> features { get; set; }
}

I put these class definitions into my application. Then I need to modify my action method to create an instance of this RootObject class (you should change the name to actually match what it's intended for).

[HttpGet]        
public ActionResult<RootObject> Get()
{
    // Create an instance of our RootObject and set the properties
    var myRootObject = new RootObject();
    myRootObject.userId = 321;
    myRootObject.account = "new";
    myRootObject.fname = "Adam";
    myRootObject.lname = "Silver";
    myRootObject.features = new List<Feature>();

    // Create an instance of a feature and set its properties
    var feature = new Feature();
    feature.available = true;
    feature.status = "open";
    feature.admin = false;

    // Add the new feature to the features collection of our RootObject    
    myRootObject.features.Add(feature);

    // Return the instance of our RootObject
    // The framework will handle serializing it to JSON for us
    return myRootObject;
}

Note that I changed the signature of your method. I made it no longer accept an IEnumerable because it wasn't clear why you had that. And I changed it to return an ActionResult after checking Microsoft's documentation .

Answer 3

Putting the comments into an answer: If you are using ActionResult, I'll assume you are using asp.net mvc. What you want is JsonResult.

    [HttpGet]
    public JsonResult Get()
    {
        return new JsonResult
        {
            Data = new
            {
                userId = 321,
                account = new
                {
                    fname = "Adam",
                    lname = "Silver",
                    features = new object[]{
                    new
                {
                    available = true,
                    status = "open",
                    admin = false
                }
                }
                }
            },
            JsonRequestBehavior = JsonRequestBehavior.AllowGet
        };
    }