MVC serialize object, list of objects, collections in Json - asp.net-mvc

Question

Parsing json returned from the controller. For some reason when returning a dictionary I need to do "ToString()" on the key element, otherwise I get an error. Why?. Are the samples below the correct way/best way to serialize json? thanks
Controller:
// JSON
public ActionResult GizmosJsonObject()
{
var gizmo = new Gizmo
{
Id = 2343,
Name = "Some awesome name",
Quantity = 32,
IntroducedDate = DateTime.Now
};
return this.Json(gizmo);
}
public ActionResult GizmosJsonObjectCollection()
{
var gizmos = new List<Gizmo>();
gizmos.Add(new Gizmo
{
Id = 102,
Name = "some name1",
Quantity = 535,
IntroducedDate = DateTime.Now
});
gizmos.Add(new Gizmo
{
Id = 122,
Name = "some name1",
Quantity = 135,
IntroducedDate = DateTime.Now
});
gizmos.Add(new Gizmo
{
Id = 562,
Name = "some name1",
Quantity = 2,
IntroducedDate = DateTime.Now
});
return this.Json(gizmos);
}
public ActionResult GizmosJsonListInts()
{
var gizmos = new List<int>();
gizmos.Add(2);
gizmos.Add(56);
gizmos.Add(32);
return this.Json(gizmos);
}
public ActionResult GizmosJsonDictionaryInts()
{
var gizmos = new Dictionary<int, int>();
gizmos.Add(23, 123);
gizmos.Add(26, 227);
gizmos.Add(54, 94323);
return this.Json(gizmos.ToDictionary(x => x.Key.ToString(), y => y.Value));
}
public ActionResult GizmosJsonDictionaryStrings()
{
var gizmos = new Dictionary<string, string>();
gizmos.Add("key1", "value1");
gizmos.Add("Key2", "value2");
gizmos.Add("key3", "value3");
return this.Json(gizmos);
}
View:
<script type="text/javascript">
/*<![CDATA[*/
$(function () {
// json object
$("a.Object").click(function (e) {
e.preventDefault();
$.ajax({
url: '#Url.Action("GizmosJsonObject", "Home")',
contentType: 'application/json',
type: 'POST',
success: function (json) {
console.log(json.Id);
console.log(json.Name);
console.log(json.IntroducedDate);
// format date
var date = new Date(parseInt(json.IntroducedDate.substr(6)));
console.log(date);
}
});
});
// json object collection
$("a.ObjectCollection").click(function (e) {
e.preventDefault();
$.ajax({
url: '#Url.Action("GizmosJsonObjectCollection", "Home")',
contentType: 'application/json',
type: 'POST',
success: function (json) {
$(json).each(function () {
console.log(this.Id);
console.log(this.Name);
console.log(this.IntroducedDate);
// format date
var date = new Date(parseInt(this.IntroducedDate.substr(6)));
console.log(date);
});
}
});
});
// json list of ints
$("a.ListInts").click(function (e) {
e.preventDefault();
$.ajax({
url: '#Url.Action("GizmosJsonListInts", "Home")',
contentType: 'application/json',
type: 'POST',
success: function (json) {
$(json).each(function (i, e) {
console.log(json[i]);
});
}
});
});
// json dictionary of ints
$("a.DictionaryInts").click(function (e) {
e.preventDefault();
$.ajax({
url: '#Url.Action("GizmosJsonDictionaryInts", "Home")',
contentType: 'application/json',
type: 'POST',
success: function (json) {
for (var key in json) {
if (json.hasOwnProperty(key)) {
var value = json[key];
console.log(key);
console.log(value);
}
}
}
});
});
// json dictionary of strings
$("a.DictionaryStrings").click(function (e) {
e.preventDefault();
$.ajax({
url: '#Url.Action("GizmosJsonDictionaryStrings", "Home")',
contentType: 'application/json',
type: 'POST',
success: function (json) {
for (var key in json) {
if (json.hasOwnProperty(key)) {
var value = json[key];
console.log(key);
console.log(value);
}
}
}
});
});
});
/*]]>*/
</script>

Answer 1

A JSON key must be of the type string. See the right sidebar here http://www.json.org/ where it states that a pair must take the form of string: value.
Just for corroboration, this document here http://www.ietf.org/rfc/rfc4627.txt states the following:
2.2. Objects
An object structure is represented as a pair of curly brackets
surrounding zero or more name/value pairs (or members). A name is a
string. A single colon comes after each name, separating the name
from the value. A single comma separates a value from a following
name. The names within an object SHOULD be unique.