How i get list from get in javascript - asp.net-mvc

Question

$(document).ready(function () {
$(".discussion").on("click", function () {
var id = $(this).attr('id');
var url = "/Chat/GetMessages/" + id;
$.get(url, null, function (data) {
var htm = "";
for (var i = 0; i < data.length; i++) {
htm += data[i].Content;
}
$("#messages").html(htm);
});
});
});
public ICollection<Message> GetMessages(int id)
{
var messages = this.disService.GetById(id).Messages;
return messages.ToList();
}
I want to show the collection from the function in controller in html. I do get request but the data from the request doesm't contain the data.
Now I have a
A circular reference was detected while serializing an object of type 'System.Collections.Generic.HashSet`1[[Forum.Model.Message, Forum.Model, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]'.

Answer 1

You have to return json as :
public JsonResult GetMessages(int id)
{
var messages = this.disService.GetById(id).Messages;
return Json(messages,JsonRequestBehavior.AllowGet)
}

Answer 2

Change your method to return JSON
public JsonResult GetMessages(int id)
{
...
return Json(messages, JsonRequestBehavior.AllowGet);
}
Edit
With the respect to the error message you indicated in your edit, you likely have circular references in your object hierarchy which is not supported by the JSON serializer. If you don't need all properties, you could only return what you want (it looks like you are using only the Content property of Messages), for example
return Json(new
{
Content = messages.Content,
AnotherProperty = messages.AnotherProperty // if you need any other properties of Message class
}, JsonRequestBehavior.AllowGet);
which has the added benefit of reducing the data being returned