If you are happy to have a dependency upon the System.Web.Helpers
assembly, then you can use the Json
class:
dynamic data = Json.Decode(json);
It is included with the MVC framework as an additional download to the .NET 4 framework. Be sure to give Vlad an upvote if that's helpful! However if you cannot assume the client environment includes this DLL, then read on.
An alternative deserialisation approach is suggested here. I modified the code slightly to fix a bug and suit my coding style. All you need is this code and a reference to System.Web.Extensions
from your project:
using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Dynamic;
using System.Linq;
using System.Text;
using System.Web.Script.Serialization;
public sealed class DynamicJsonConverter : JavaScriptConverter
{
public override object Deserialize(IDictionary<string, object> dictionary, Type type, JavaScriptSerializer serializer)
{
if (dictionary == null)
throw new ArgumentNullException("dictionary");
return type == typeof(object) ? new DynamicJsonObject(dictionary) : null;
}
public override IDictionary<string, object> Serialize(object obj, JavaScriptSerializer serializer)
{
throw new NotImplementedException();
}
public override IEnumerable<Type> SupportedTypes
{
get { return new ReadOnlyCollection<Type>(new List<Type>(new[] { typeof(object) })); }
}
#region Nested type: DynamicJsonObject
private sealed class DynamicJsonObject : DynamicObject
{
private readonly IDictionary<string, object> _dictionary;
public DynamicJsonObject(IDictionary<string, object> dictionary)
{
if (dictionary == null)
throw new ArgumentNullException("dictionary");
_dictionary = dictionary;
}
public override string ToString()
{
var sb = new StringBuilder("{");
ToString(sb);
return sb.ToString();
}
private void ToString(StringBuilder sb)
{
var firstInDictionary = true;
foreach (var pair in _dictionary)
{
if (!firstInDictionary)
sb.Append(",");
firstInDictionary = false;
var value = pair.Value;
var name = pair.Key;
if (value is string)
{
sb.AppendFormat("{0}:\"{1}\"", name, value);
}
else if (value is IDictionary<string, object>)
{
new DynamicJsonObject((IDictionary<string, object>)value).ToString(sb);
}
else if (value is ArrayList)
{
sb.Append(name + ":[");
var firstInArray = true;
foreach (var arrayValue in (ArrayList)value)
{
if (!firstInArray)
sb.Append(",");
firstInArray = false;
if (arrayValue is IDictionary<string, object>)
new DynamicJsonObject((IDictionary<string, object>)arrayValue).ToString(sb);
else if (arrayValue is string)
sb.AppendFormat("\"{0}\"", arrayValue);
else
sb.AppendFormat("{0}", arrayValue);
}
sb.Append("]");
}
else
{
sb.AppendFormat("{0}:{1}", name, value);
}
}
sb.Append("}");
}
public override bool TryGetMember(GetMemberBinder binder, out object result)
{
if (!_dictionary.TryGetValue(binder.Name, out result))
{
// return null to avoid exception. caller can check for null this way...
result = null;
return true;
}
result = WrapResultObject(result);
return true;
}
public override bool TryGetIndex(GetIndexBinder binder, object[] indexes, out object result)
{
if (indexes.Length == 1 && indexes[0] != null)
{
if (!_dictionary.TryGetValue(indexes[0].ToString(), out result))
{
// return null to avoid exception. caller can check for null this way...
result = null;
return true;
}
result = WrapResultObject(result);
return true;
}
return base.TryGetIndex(binder, indexes, out result);
}
private static object WrapResultObject(object result)
{
var dictionary = result as IDictionary<string, object>;
if (dictionary != null)
return new DynamicJsonObject(dictionary);
var arrayList = result as ArrayList;
if (arrayList != null && arrayList.Count > 0)
{
return arrayList[0] is IDictionary<string, object>
? new List<object>(arrayList.Cast<IDictionary<string, object>>().Select(x => new DynamicJsonObject(x)))
: new List<object>(arrayList.Cast<object>());
}
return result;
}
}
#endregion
}
You can use it like this:
string json = ...;
var serializer = new JavaScriptSerializer();
serializer.RegisterConverters(new[] { new DynamicJsonConverter() });
dynamic obj = serializer.Deserialize(json, typeof(object));
So, given a JSON string:
{
"Items":[
{ "Name":"Apple", "Price":12.3 },
{ "Name":"Grape", "Price":3.21 }
],
"Date":"21/11/2010"
}
The following code will work at runtime:
dynamic data = serializer.Deserialize(json, typeof(object));
data.Date; // "21/11/2010"
data.Items.Count; // 2
data.Items[0].Name; // "Apple"
data.Items[0].Price; // 12.3 (as a decimal)
data.Items[1].Name; // "Grape"
data.Items[1].Price; // 3.21 (as a decimal)
From my initial comment:
A typical scenario is one where the key is different from the one used at the other side. This is the most probable cause, but you might also want to check the way you handle streams, because you really lack .close() and possibly .flush() statements. You also assume that you always can read all the data into the buffer, which may not be the case.
The key was indeed calculated incorrectly.
Best Answer
The user id (you provide as the second argument of the
done
function) is saved in the session and is later used to retrieve the whole object via thedeserializeUser
function.serializeUser
determines which data of the user object should be stored in the session. The result of the serializeUser method is attached to the session asreq.session.passport.user = {}
. Here for instance, it would be (as we provide the user id as the key)req.session.passport.user = {id: 'xyz'}
The first argument of
deserializeUser
corresponds to the key of the user object that was given to thedone
function (see 1.). So your whole object is retrieved with help of that key. That key here is the user id (key can be any key of the user object i.e. name,email etc). IndeserializeUser
that key is matched with the in memory array / database or any data resource.The fetched object is attached to the request object as
req.user
Visual Flow