How to read JSON object to WebAPI

Question

I\'ve checked a few similar questions, but none of the answers seem to fit (or dumb it down enough for me). So, I have a really simple WebAPI to check if user with an email

Answer 1

Either change it to a POST to send the object you are trying to send through the request body or change you method signature to accept the email address.

var param = { "email": "ex.ample@email.com" };
$.ajax({
    url: "/api/users/" + param.email,
    type: "GET",
    contentType: "application/json; charset=utf-8",
    dataType: "json",
    success: function (data) {
        if (data == true) {
            // notify user that email exists
        }
        else {
            // not taken
        }             
    }                      
});

[HttpGet, Route("api/users/{emailaddress}")]
public bool Get(string emailaddress)
{
    string email = emailaddress;
    UserStore<ApplicationUser> userStore = new UserStore<ApplicationUser>();
    ApplicationUserManager<ApplicationUser> manager = new ApplicationUserManager<ApplicationUser>(userStore);
    ApplicationUser user = manager.FindByEmail(email);

    if (user != null)
    {
        return true;
    }

    else
    {
        return false;
    }
}

//helper class:
public class UserResponse
{
    public string email { get; set; }
}

Answer 2

You can create an object in your JavaScript:

var myData= {
     Email: "me@email.com"
};

This creates an object, matching the object expected by the controller.

You then set the Ajax call to pass this as the data property:

$.ajax({
    url: "/api/User/",
    type: "GET",
    data: myData,
    contentType: "application/json; charset=utf-8",
    dataType: "json",
    success: function (data) {
        if (data == true) {
            // notify user that email exists
        }
        else {
            // not taken
        }             
    }                      
});

I like this approach, as you can then add more properties as required. However, if you are only passing the email address, you might want to just pass a string.

Answer 3

var dto = {        
    Email: "ex.ample@email.com"
};

$.ajax({
    url: "/api/User/",
    type: "GET",
    data: dto,
    contentType: "application/json; charset=utf-8",
    dataType: "json",
    success: function (data) {
        if (data == true) {
            // notify user that email exists
        }
        else {
            // not taken
        }             
    }                      
});

Answer 4

Problem: Your current implementation are sending the email as an entity on a GET request. This is a problem because GET requests does not carry an entity HTTP/1.1 Methods Solution: Change the request to a POST

Now because you are POST'ing the email from your client to your api, you have to change the API implementation to POST:

public bool Post(UserResponse id)

---

To make sure your posted entity is bound correctly, you can use [FromBody] like:

public bool Post([FromBody] UserResponse id)

If you do this (and you have not yet overridden the default model binder), you have to annotate your model like:

[DataContract]
public class UserResponse
{
    [DataMember]
    public string email { get; set; }
}

I think that is all - hope it works :)