How to use C# example using JsonPath? - c#

I'm trying to use JsonPath for .NET (http://code.google.com/p/jsonpath/downloads/list) and I'm having trouble finding an example of how to parse a Json string and a JsonPath string and get a result.
Has anyone used this?

The problem you are experiencing is that the C# version of JsonPath does not include a Json parser so you have to use it with another Json framework that handles serialization and deserialization.
The way JsonPath works is to use an interface called IJsonPathValueSystem to traverse parsed Json objects. JsonPath comes with a built-in BasicValueSystem that uses the IDictionary interface to represent Json objects and the IList interface to represent Json arrays.
You can create your own BasicValueSystem-compatible Json objects by constructing them using C# collection initializers but this is not of much use when your Json is coming in in the form of strings from a remote server, for example.
So if only you could take a Json string and parse it into a nested structure of IDictionary objects, IList arrays, and primitive values, you could then use JsonPath to filter it! As luck would have it, we can use Json.NET which has good serialization and deserialization capabilities to do that part of the job.
Unfortunately, Json.NET does not deserialize Json strings into a format compatible with the BasicValueSystem. So the first task for using JsonPath with Json.NET is to write a JsonNetValueSystem that implements IJsonPathValueSystem and that understands the JObject objects, JArray arrays, and JValue values that JObject.Parse produces.
So download both JsonPath and Json.NET and put them into a C# project. Then add this class to that project:
public sealed class JsonNetValueSystem : IJsonPathValueSystem
{
public bool HasMember(object value, string member)
{
if (value is JObject)
return (value as JObject).Properties().Any(property => property.Name == member);
if (value is JArray)
{
int index = ParseInt(member, -1);
return index >= 0 && index < (value as JArray).Count;
}
return false;
}
public object GetMemberValue(object value, string member)
{
if (value is JObject)
{
var memberValue = (value as JObject)[member];
return memberValue;
}
if (value is JArray)
{
int index = ParseInt(member, -1);
return (value as JArray)[index];
}
return null;
}
public IEnumerable GetMembers(object value)
{
var jobject = value as JObject;
return jobject.Properties().Select(property => property.Name);
}
public bool IsObject(object value)
{
return value is JObject;
}
public bool IsArray(object value)
{
return value is JArray;
}
public bool IsPrimitive(object value)
{
if (value == null)
throw new ArgumentNullException("value");
return value is JObject || value is JArray ? false : true;
}
private int ParseInt(string s, int defaultValue)
{
int result;
return int.TryParse(s, out result) ? result : defaultValue;
}
}
Now with all three of these pieces we can write a sample JsonPath program:
class Program
{
static void Main(string[] args)
{
var input = #"
{ ""store"": {
""book"": [
{ ""category"": ""reference"",
""author"": ""Nigel Rees"",
""title"": ""Sayings of the Century"",
""price"": 8.95
},
{ ""category"": ""fiction"",
""author"": ""Evelyn Waugh"",
""title"": ""Sword of Honour"",
""price"": 12.99
},
{ ""category"": ""fiction"",
""author"": ""Herman Melville"",
""title"": ""Moby Dick"",
""isbn"": ""0-553-21311-3"",
""price"": 8.99
},
{ ""category"": ""fiction"",
""author"": ""J. R. R. Tolkien"",
""title"": ""The Lord of the Rings"",
""isbn"": ""0-395-19395-8"",
""price"": 22.99
}
],
""bicycle"": {
""color"": ""red"",
""price"": 19.95
}
}
}
";
var json = JObject.Parse(input);
var context = new JsonPathContext { ValueSystem = new JsonNetValueSystem() };
var values = context.SelectNodes(json, "$.store.book[*].author").Select(node => node.Value);
Console.WriteLine(JsonConvert.SerializeObject(values));
Console.ReadKey();
}
}
which produces this output:
["Nigel Rees","Evelyn Waugh","Herman Melville","J. R. R. Tolkien"]
This example is based on the Javascript sample at the JsonPath site:
Javascript Usage and Example

For those that don't like LINQ (.NET 2.0):
namespace JsonPath
{
public sealed class JsonNetValueSystem : IJsonPathValueSystem
{
public bool HasMember(object value, string member)
{
if (value is Newtonsoft.Json.Linq.JObject)
{
// return (value as JObject).Properties().Any(property => property.Name == member);
foreach (Newtonsoft.Json.Linq.JProperty property in (value as Newtonsoft.Json.Linq.JObject).Properties())
{
if (property.Name == member)
return true;
}
return false;
}
if (value is Newtonsoft.Json.Linq.JArray)
{
int index = ParseInt(member, -1);
return index >= 0 && index < (value as Newtonsoft.Json.Linq.JArray).Count;
}
return false;
}
public object GetMemberValue(object value, string member)
{
if (value is Newtonsoft.Json.Linq.JObject)
{
var memberValue = (value as Newtonsoft.Json.Linq.JObject)[member];
return memberValue;
}
if (value is Newtonsoft.Json.Linq.JArray)
{
int index = ParseInt(member, -1);
return (value as Newtonsoft.Json.Linq.JArray)[index];
}
return null;
}
public System.Collections.IEnumerable GetMembers(object value)
{
System.Collections.Generic.List<string> ls = new System.Collections.Generic.List<string>();
var jobject = value as Newtonsoft.Json.Linq.JObject;
/// return jobject.Properties().Select(property => property.Name);
foreach (Newtonsoft.Json.Linq.JProperty property in jobject.Properties())
{
ls.Add(property.Name);
}
return ls;
}
public bool IsObject(object value)
{
return value is Newtonsoft.Json.Linq.JObject;
}
public bool IsArray(object value)
{
return value is Newtonsoft.Json.Linq.JArray;
}
public bool IsPrimitive(object value)
{
if (value == null)
throw new System.ArgumentNullException("value");
return value is Newtonsoft.Json.Linq.JObject || value is Newtonsoft.Json.Linq.JArray ? false : true;
}
private int ParseInt(string s, int defaultValue)
{
int result;
return int.TryParse(s, out result) ? result : defaultValue;
}
}
}
Usage:
object obj = Newtonsoft.Json.JsonConvert.DeserializeObject(input);
JsonPath.JsonPathContext context = new JsonPath.JsonPathContext { ValueSystem = new JsonPath.JsonNetValueSystem() };
foreach (JsonPath.JsonPathNode node in context.SelectNodes(obj, "$.store.book[*].author"))
{
Console.WriteLine(node.Value);
}

using Newtonsoft.Json.Linq yo can use function SelectToken and try out yous JsonPath
Check documentation https://www.newtonsoft.com/json/help/html/T_Newtonsoft_Json_Linq_JObject.htm
Object jsonObj = JObject.Parse(stringResult);
JToken pathResult = jsonObj.SelectToken("results[0].example");
return pathResult.ToString();

I found that the internal JavaScriptSerializer() can work just fine as long as filtering is not required.
Using the dataset and examples from JsonPath Dataset + Examples
My source for the JsonPath implementation was GitHub
public static string SelectFromJson(string inputJsonData, string inputJsonPath)
{
// Use the serializer to deserialize the JSON but also to create the snippets
var serializer = new System.Web.Script.Serialization.JavaScriptSerializer();
serializer.MaxJsonLength = Int32.MaxValue;
dynamic dynJson = serializer.Deserialize<object>(inputJsonData);
var jsonPath = new JsonPath.JsonPathContext();
var jsonResults = jsonPath.Select(dynJson, inputJsonPath);
var valueList = new List<string>();
foreach (var node in jsonResults)
{
if (node is string)
{
valueList.Add(node);
}
else
{
// If the object is too complex then return a list of JSON snippets
valueList.Add(serializer.Serialize(node));
}
}
return String.Join("\n", valueList);
}
The function is used as follows.
var result = SelectFromJson(#"
{ ""store"": {
""book"": [
{ ""category"": ""fiction"",
""author"": ""J. R. R. Tolkien"",
""title"": ""The Lord of the Rings"",
""isbn"": ""0-395-19395-8"",
""price"": 22.99
}
]
}
}", "$.store.book[*].author");

Related

Creating GraphQL Structure from Dot Notation String in c#

The following javascript question is the same problem i'm attempting to solve but in c#
How can I merge 2 dot notation strings to a GraphQL query string
Expected structure is
{
"Case": {
"Owner": {
"Name": null,
"ProfilePic": null
},
"CaseNo": null,
"FieldOfLaw":{
"Name": null
},
"CaseType": {
"Name": null
},
"CaseSubType": {
"Name": null
},
},
"Client":{
"Policy":{
"PolicyNo": null
}
}
}
and my current output is
{
"Case": {
"Owner": {
"Name": null,
"ProfilePic": null
},
"CaseNo": null,
"FieldOfLaw": null,
"CaseType": null,
"CaseSubType": null
}
}
Below is my attempt using ExpandoObjects to try dynamically generate the objects needed. Any advice or pointers in the right direction would be appreciated.
public static void Main(string[] args)
{
var FieldList = new List<string>
{
"Case.Owner.Name",
"Case.Owner.ProfilePic",
"Case.CaseNo",
"Case.FieldOfLaw.Name",
"Case.CaseType.Name",
"Case.CaseSubType.Name",
"Client.Policy.PolicyNo",
};
Parser graphQL = new Parser();
var result = graphQL.Parse(FieldList);
Console.Write(result);
}
Below is the actual parse method, so i'm running an aggregation function over each element to create and return the expando objects into the initial holder. I traverse each split string recursively and exit the recursion once there are no more items left in the split list.
public class Parser
{
public string Parse(List<string> fieldList)
{
// List<ExpandoObject> queryHolder = new List<ExpandoObject>();
ExpandoObject intialSeed = new ExpandoObject();
fieldList.Aggregate(intialSeed, (holder, field) =>
{
holder = ParseToObject(holder, field.Split('.').ToList());
return holder;
});
return JsonConvert.SerializeObject(intialSeed);
}
public ExpandoObject ParseToObject(ExpandoObject holder, List<string> fieldSplit, string previousKey = null)
{
if (fieldSplit.Any())
{
var item = fieldSplit.Shift();
if (item == null)
return holder;
// If the current item doesn't exists in the dictionary
if (!((IDictionary<string, object>)holder).ContainsKey(item))
{
if (((IDictionary<string, object>)holder).Keys.Count() == 0)
holder.TryAdd(item, null);
else
_ = ((IDictionary<string, object>)holder).GetItemByKeyRecursively(previousKey, item);
}
previousKey = item;
ParseToObject(holder, fieldSplit, previousKey);
}
return holder;
}
}
Here are my two extensions methods, i'm having an issue with the GetItemByKeyRecursively when it goes into the 3rd level in it's recursion so example.
I'm adding FieldOfLaw it adds the property to the Case expandoObject but doesn't know how to get back to the leaf containing Owner, CaseNo etc.
public static class CollectionExtensions
{
public static T Shift<T>(this IList<T> list)
{
var shiftedElement = list.FirstOrDefault();
list.RemoveAt(0);
return shiftedElement;
}
public static IDictionary<string, object> GetItemByKeyRecursively(this IDictionary<string, object> dictionary, string parentKey, string keyToCreate)
{
foreach (string key in dictionary.Keys)
{
var leaf = dictionary[key];
if (key == parentKey)
{
var #value = dictionary[key];
if (#value is ExpandoObject)
{
(#value as ExpandoObject).TryAdd(keyToCreate, null);
}
else if (#value == null)
{
var item = new ExpandoObject();
item.TryAdd(keyToCreate, null);
dictionary[key] = item;
}
return dictionary;
}
if (leaf == null)
continue;
return GetItemByKeyRecursively((IDictionary<string, object>)leaf, parentKey, keyToCreate);
}
return null;
}
}
Nothing you can't accomplish mostly declaratively.
public string Parse(List<string> fieldList)
{
var fieldPaths = fieldList.Select(x => x.Split('.').ToList());
var groups = fieldPaths.GroupBy(x => x.First(), x => x.Skip(1));
return ParseGroups(groups, 1);
}
private string ParseGroups(IEnumerable<IGrouping<string, IEnumerable<string>>> groups, int level)
{
string indent = new string('\t', level - 1);
var groupResults = groups.Select(g =>
!g.First().Any() ?
$"\t{indent}{g.Key}: null" :
$"\t{indent}{g.Key}: " + string.Join(", \n",
ParseGroups(g.GroupBy(x => x.First(), x => x.Skip(1)), level + 1))
);
return indent + "{\n" + string.Join(", \n", groupResults) + "\n" + indent + "}";
}
See the complete sample code here: https://dotnetfiddle.net/RLygjt

.Net Core 3.0 JsonSerializer populate existing object

I'm preparing a migration from ASP.NET Core 2.2 to 3.0.
As I don't use more advanced JSON features (but maybe one as described below), and 3.0 now comes with a built-in namespace/classes for JSON, System.Text.Json, I decided to see if I could drop the previous default Newtonsoft.Json.
Do note, I'm aware that System.Text.Json will not completely replace Newtonsoft.Json.
I managed to do that everywhere, e.g.
var obj = JsonSerializer.Parse<T>(jsonstring);
var jsonstring = JsonSerializer.ToString(obj);
but in one place, where I populate an existing object.
With Newtonsoft.Json one can do
JsonConvert.PopulateObject(jsonstring, obj);
The built-in System.Text.Json namespace has some additional classes, like JsonDocumnet, JsonElement and Utf8JsonReader, though I can't find any that take an existing object as a parameter.
Nor am I experienced enough to see how to make use of the existing one's.
There might be a possible upcoming feature in .Net Core (thanks to Mustafa Gursel for the link), but meanwhile (and what if it doesn't),...
...I now wonder, is it possible to achieve something similar as what one can do with PopulateObject?
I mean, is it possible with any of the other System.Text.Json classes to accomplish the same, and update/replace only the properties set?,... or some other clever workaround?
Here is a sample input/output of what I am looking for, and it need to be generic as the object passed into the deserialization method is of type <T>). I have 2 Json string's to be parsed into an object, where the first have some default properties set, and the second some, e.g.
Note, a property value can be of any other type than a string.
Json string 1:
{
"Title": "Startpage",
"Link": "/index",
}
Json string 2:
{
"Head": "Latest news"
"Link": "/news"
}
Using the 2 Json strings above, I want an object resulting in:
{
"Title": "Startpage",
"Head": "Latest news",
"Link": "/news"
}
As seen in above sample, if properties in the 2nd has values/is set, it replace values in the 1st (as with "Head" and "Link"), if not, existing value persist (as with "Title")
So assuming that Core 3 doesn't support this out of the box, let's try to work around this thing. So, what's our problem?
We want a method that overwrites some properties of an existing object with the ones from a json string. So our method will have a signature of:
void PopulateObject<T>(T target, string jsonSource) where T : class
We don't really want any custom parsing as it's cumbersome, so we'll try the obvious approach - deserialize jsonSource and copy the result properties into our object. We cannot, however, just go
T updateObject = JsonSerializer.Parse<T>(jsonSource);
CopyUpdatedProperties(target, updateObject);
That's because for a type
class Example
{
int Id { get; set; }
int Value { get; set; }
}
and a JSON
{
"Id": 42
}
we will get updateObject.Value == 0. Now we don't know if 0 is the new updated value or if it just wasn't updated, so we need to know exactly which properties jsonSource contains.
Fortunately, the System.Text.Json API allows us to examine the structure of the parsed JSON.
using var json = JsonDocument.Parse(jsonSource).RootElement;
We can now enumerate over all properties and copy them.
foreach (var property in json.EnumerateObject())
{
OverwriteProperty(target, property);
}
We will copy the value using reflection:
void OverwriteProperty<T>(T target, JsonProperty updatedProperty) where T : class
{
var propertyInfo = typeof(T).GetProperty(updatedProperty.Name);
if (propertyInfo == null)
{
return;
}
var propertyType = propertyInfo.PropertyType;
v̶a̶r̶ ̶p̶a̶r̶s̶e̶d̶V̶a̶l̶u̶e̶ ̶=̶ ̶J̶s̶o̶n̶S̶e̶r̶i̶a̶l̶i̶z̶e̶r̶.̶P̶a̶r̶s̶e̶(̶u̶p̶d̶a̶t̶e̶d̶P̶r̶o̶p̶e̶r̶t̶y̶.̶V̶a̶l̶u̶e̶,̶ ̶p̶r̶o̶p̶e̶r̶t̶y̶T̶y̶p̶e̶)̶;̶
var parsedValue = JsonSerializer.Deserialize(
updatedProperty.Value.GetRawText(),
propertyType);
propertyInfo.SetValue(target, parsedValue);
}
We can see here that what we're doing is a shallow update. If the object contains another complex object as its property, that one will be copied and overwritten as a whole, not updated. If you require deep updates, this method needs to be changed to extract the current value of the property and then call the PopulateObject recursively if the property's type is a reference type (that will also require accepting Type as a parameter in PopulateObject).
Joining it all together we get:
void PopulateObject<T>(T target, string jsonSource) where T : class
{
using var json = JsonDocument.Parse(jsonSource).RootElement;
foreach (var property in json.EnumerateObject())
{
OverwriteProperty(target, property);
}
}
void OverwriteProperty<T>(T target, JsonProperty updatedProperty) where T : class
{
var propertyInfo = typeof(T).GetProperty(updatedProperty.Name);
if (propertyInfo == null)
{
return;
}
var propertyType = propertyInfo.PropertyType;
v̶a̶r̶ ̶p̶a̶r̶s̶e̶d̶V̶a̶l̶u̶e̶ ̶=̶ ̶J̶s̶o̶n̶S̶e̶r̶i̶a̶l̶i̶z̶e̶r̶.̶P̶a̶r̶s̶e̶(̶u̶p̶d̶a̶t̶e̶d̶P̶r̶o̶p̶e̶r̶t̶y̶.̶V̶a̶l̶u̶e̶,̶ ̶p̶r̶o̶p̶e̶r̶t̶y̶T̶y̶p̶e̶)̶;̶
var parsedValue = JsonSerializer.Deserialize(
updatedProperty.Value.GetRawText(),
propertyType);
propertyInfo.SetValue(target, parsedValue);
}
How robust is this? Well, it certainly won't do anything sensible for a JSON array, but I'm not sure how you'd expect a PopulateObject method to work on an array to begin with. I don't know how it compares in performance to the Json.Net version, you'd have to test that by yourself. It also silently ignores properties that are not in the target type, by design. I thought it was the most sensible approach, but you might think otherwise, in that case the property null-check has to be replaced with an exception throw.
EDIT:
I went ahead and implemented a deep copy:
void PopulateObject<T>(T target, string jsonSource) where T : class =>
PopulateObject(target, jsonSource, typeof(T));
void OverwriteProperty<T>(T target, JsonProperty updatedProperty) where T : class =>
OverwriteProperty(target, updatedProperty, typeof(T));
void PopulateObject(object target, string jsonSource, Type type)
{
using var json = JsonDocument.Parse(jsonSource).RootElement;
foreach (var property in json.EnumerateObject())
{
OverwriteProperty(target, property, type);
}
}
void OverwriteProperty(object target, JsonProperty updatedProperty, Type type)
{
var propertyInfo = type.GetProperty(updatedProperty.Name);
if (propertyInfo == null)
{
return;
}
var propertyType = propertyInfo.PropertyType;
object parsedValue;
if (propertyType.IsValueType || propertyType == typeof(string))
{
̶p̶a̶r̶s̶e̶d̶V̶a̶l̶u̶e̶ ̶=̶ ̶J̶s̶o̶n̶S̶e̶r̶i̶a̶l̶i̶z̶e̶r̶.̶P̶a̶r̶s̶e̶(̶u̶p̶d̶a̶t̶e̶d̶P̶r̶o̶p̶e̶r̶t̶y̶.̶V̶a̶l̶u̶e̶,̶ ̶p̶r̶o̶p̶e̶r̶t̶y̶T̶y̶p̶e̶)̶;̶
parsedValue = JsonSerializer.Deserialize(
updatedProperty.Value.GetRawText(),
propertyType);
}
else
{
parsedValue = propertyInfo.GetValue(target);
P̶o̶p̶u̶l̶a̶t̶e̶O̶b̶j̶e̶c̶t̶(̶p̶a̶r̶s̶e̶d̶V̶a̶l̶u̶e̶,̶ ̶u̶p̶d̶a̶t̶e̶d̶P̶r̶o̶p̶e̶r̶t̶y̶.̶V̶a̶l̶u̶e̶,̶ ̶p̶r̶o̶p̶e̶r̶t̶y̶T̶y̶p̶e̶)̶;̶
PopulateObject(
parsedValue,
updatedProperty.Value.GetRawText(),
propertyType);
}
propertyInfo.SetValue(target, parsedValue);
}
To make this more robust you'd either have to have a separate PopulateObjectDeep method or pass PopulateObjectOptions or something similar with a deep/shallow flag.
EDIT 2:
The point of deep-copying is so that if we have an object
{
"Id": 42,
"Child":
{
"Id": 43,
"Value": 32
},
"Value": 128
}
and populate it with
{
"Child":
{
"Value": 64
}
}
we'd get
{
"Id": 42,
"Child":
{
"Id": 43,
"Value": 64
},
"Value": 128
}
In case of a shallow copy we'd get Id = 0 in the copied child.
EDIT 3:
As #ldam pointed out, this no longer works in stable .NET Core 3.0, because the API was changed. The Parse method is now Deserialize and you have to dig deeper to get to a JsonElement's value. There is an active issue in the corefx repo to allow direct deserialization of a JsonElement. Right now the closest solution is to use GetRawText(). I went ahead and edited the code above to work, leaving the old version struck-through.
Here is some sample code that does it. It's using the new Utf8JsonReader struct so it populates the object at the same time it parses it. It supports JSON/CLR types equivalence, nested objects (creates if they don't exist), lists and arrays.
var populator = new JsonPopulator();
var obj = new MyClass();
populator.PopulateObject(obj, "{\"Title\":\"Startpage\",\"Link\":\"/index\"}");
populator.PopulateObject(obj, "{\"Head\":\"Latest news\",\"Link\":\"/news\"}");
public class MyClass
{
public string Title { get; set; }
public string Head { get; set; }
public string Link { get; set; }
}
Note it doesn't support all of what you would probably expect, but you can override or customize it. Things that could be added: 1) naming convention. You'd have to override the GetProperty method. 2) dictionaries or expando objects. 3) performance can be improved because it uses Reflection instead of MemberAccessor/delegate techniques
public class JsonPopulator
{
public void PopulateObject(object obj, string jsonString, JsonSerializerOptions options = null) => PopulateObject(obj, jsonString != null ? Encoding.UTF8.GetBytes(jsonString) : null, options);
public virtual void PopulateObject(object obj, ReadOnlySpan<byte> jsonData, JsonSerializerOptions options = null)
{
options ??= new JsonSerializerOptions();
var state = new JsonReaderState(new JsonReaderOptions { AllowTrailingCommas = options.AllowTrailingCommas, CommentHandling = options.ReadCommentHandling, MaxDepth = options.MaxDepth });
var reader = new Utf8JsonReader(jsonData, isFinalBlock: true, state);
new Worker(this, reader, obj, options);
}
protected virtual PropertyInfo GetProperty(ref Utf8JsonReader reader, JsonSerializerOptions options, object obj, string propertyName)
{
if (obj == null)
throw new ArgumentNullException(nameof(obj));
if (propertyName == null)
throw new ArgumentNullException(nameof(propertyName));
var prop = obj.GetType().GetProperty(propertyName);
return prop;
}
protected virtual bool SetPropertyValue(ref Utf8JsonReader reader, JsonSerializerOptions options, object obj, string propertyName)
{
if (obj == null)
throw new ArgumentNullException(nameof(obj));
if (propertyName == null)
throw new ArgumentNullException(nameof(propertyName));
var prop = GetProperty(ref reader, options, obj, propertyName);
if (prop == null)
return false;
if (!TryReadPropertyValue(ref reader, options, prop.PropertyType, out var value))
return false;
prop.SetValue(obj, value);
return true;
}
protected virtual bool TryReadPropertyValue(ref Utf8JsonReader reader, JsonSerializerOptions options, Type propertyType, out object value)
{
if (propertyType == null)
throw new ArgumentNullException(nameof(reader));
if (reader.TokenType == JsonTokenType.Null)
{
value = null;
return !propertyType.IsValueType || Nullable.GetUnderlyingType(propertyType) != null;
}
if (propertyType == typeof(object)) { value = ReadValue(ref reader); return true; }
if (propertyType == typeof(string)) { value = JsonSerializer.Deserialize<JsonElement>(ref reader, options).GetString(); return true; }
if (propertyType == typeof(int) && reader.TryGetInt32(out var i32)) { value = i32; return true; }
if (propertyType == typeof(long) && reader.TryGetInt64(out var i64)) { value = i64; return true; }
if (propertyType == typeof(DateTime) && reader.TryGetDateTime(out var dt)) { value = dt; return true; }
if (propertyType == typeof(DateTimeOffset) && reader.TryGetDateTimeOffset(out var dto)) { value = dto; return true; }
if (propertyType == typeof(Guid) && reader.TryGetGuid(out var guid)) { value = guid; return true; }
if (propertyType == typeof(decimal) && reader.TryGetDecimal(out var dec)) { value = dec; return true; }
if (propertyType == typeof(double) && reader.TryGetDouble(out var dbl)) { value = dbl; return true; }
if (propertyType == typeof(float) && reader.TryGetSingle(out var sgl)) { value = sgl; return true; }
if (propertyType == typeof(uint) && reader.TryGetUInt32(out var ui32)) { value = ui32; return true; }
if (propertyType == typeof(ulong) && reader.TryGetUInt64(out var ui64)) { value = ui64; return true; }
if (propertyType == typeof(byte[]) && reader.TryGetBytesFromBase64(out var bytes)) { value = bytes; return true; }
if (propertyType == typeof(bool))
{
if (reader.TokenType == JsonTokenType.False || reader.TokenType == JsonTokenType.True)
{
value = reader.GetBoolean();
return true;
}
}
// fallback here
return TryConvertValue(ref reader, propertyType, out value);
}
protected virtual object ReadValue(ref Utf8JsonReader reader)
{
switch (reader.TokenType)
{
case JsonTokenType.False: return false;
case JsonTokenType.True: return true;
case JsonTokenType.Null: return null;
case JsonTokenType.String: return reader.GetString();
case JsonTokenType.Number: // is there a better way?
if (reader.TryGetInt32(out var i32))
return i32;
if (reader.TryGetInt64(out var i64))
return i64;
if (reader.TryGetUInt64(out var ui64)) // uint is already handled by i64
return ui64;
if (reader.TryGetSingle(out var sgl))
return sgl;
if (reader.TryGetDouble(out var dbl))
return dbl;
if (reader.TryGetDecimal(out var dec))
return dec;
break;
}
throw new NotSupportedException();
}
// we're here when json types & property types don't match exactly
protected virtual bool TryConvertValue(ref Utf8JsonReader reader, Type propertyType, out object value)
{
if (propertyType == null)
throw new ArgumentNullException(nameof(reader));
if (propertyType == typeof(bool))
{
if (reader.TryGetInt64(out var i64)) // one size fits all
{
value = i64 != 0;
return true;
}
}
// TODO: add other conversions
value = null;
return false;
}
protected virtual object CreateInstance(ref Utf8JsonReader reader, Type propertyType)
{
if (propertyType.GetConstructor(Type.EmptyTypes) == null)
return null;
// TODO: handle custom instance creation
try
{
return Activator.CreateInstance(propertyType);
}
catch
{
// swallow
return null;
}
}
private class Worker
{
private readonly Stack<WorkerProperty> _properties = new Stack<WorkerProperty>();
private readonly Stack<object> _objects = new Stack<object>();
public Worker(JsonPopulator populator, Utf8JsonReader reader, object obj, JsonSerializerOptions options)
{
_objects.Push(obj);
WorkerProperty prop;
WorkerProperty peek;
while (reader.Read())
{
switch (reader.TokenType)
{
case JsonTokenType.PropertyName:
prop = new WorkerProperty();
prop.PropertyName = Encoding.UTF8.GetString(reader.ValueSpan);
_properties.Push(prop);
break;
case JsonTokenType.StartObject:
case JsonTokenType.StartArray:
if (_properties.Count > 0)
{
object child = null;
var parent = _objects.Peek();
PropertyInfo pi = null;
if (parent != null)
{
pi = populator.GetProperty(ref reader, options, parent, _properties.Peek().PropertyName);
if (pi != null)
{
child = pi.GetValue(parent); // mimic ObjectCreationHandling.Auto
if (child == null && pi.CanWrite)
{
if (reader.TokenType == JsonTokenType.StartArray)
{
if (!typeof(IList).IsAssignableFrom(pi.PropertyType))
break; // don't create if we can't handle it
}
if (reader.TokenType == JsonTokenType.StartArray && pi.PropertyType.IsArray)
{
child = Activator.CreateInstance(typeof(List<>).MakeGenericType(pi.PropertyType.GetElementType())); // we can't add to arrays...
}
else
{
child = populator.CreateInstance(ref reader, pi.PropertyType);
if (child != null)
{
pi.SetValue(parent, child);
}
}
}
}
}
if (reader.TokenType == JsonTokenType.StartObject)
{
_objects.Push(child);
}
else if (child != null) // StartArray
{
peek = _properties.Peek();
peek.IsArray = pi.PropertyType.IsArray;
peek.List = (IList)child;
peek.ListPropertyType = GetListElementType(child.GetType());
peek.ArrayPropertyInfo = pi;
}
}
break;
case JsonTokenType.EndObject:
_objects.Pop();
if (_properties.Count > 0)
{
_properties.Pop();
}
break;
case JsonTokenType.EndArray:
if (_properties.Count > 0)
{
prop = _properties.Pop();
if (prop.IsArray)
{
var array = Array.CreateInstance(GetListElementType(prop.ArrayPropertyInfo.PropertyType), prop.List.Count); // array is finished, convert list into a real array
prop.List.CopyTo(array, 0);
prop.ArrayPropertyInfo.SetValue(_objects.Peek(), array);
}
}
break;
case JsonTokenType.False:
case JsonTokenType.Null:
case JsonTokenType.Number:
case JsonTokenType.String:
case JsonTokenType.True:
peek = _properties.Peek();
if (peek.List != null)
{
if (populator.TryReadPropertyValue(ref reader, options, peek.ListPropertyType, out var item))
{
peek.List.Add(item);
}
break;
}
prop = _properties.Pop();
var current = _objects.Peek();
if (current != null)
{
populator.SetPropertyValue(ref reader, options, current, prop.PropertyName);
}
break;
}
}
}
private static Type GetListElementType(Type type)
{
if (type.IsArray)
return type.GetElementType();
foreach (Type iface in type.GetInterfaces())
{
if (!iface.IsGenericType) continue;
if (iface.GetGenericTypeDefinition() == typeof(IDictionary<,>)) return iface.GetGenericArguments()[1];
if (iface.GetGenericTypeDefinition() == typeof(IList<>)) return iface.GetGenericArguments()[0];
if (iface.GetGenericTypeDefinition() == typeof(ICollection<>)) return iface.GetGenericArguments()[0];
if (iface.GetGenericTypeDefinition() == typeof(IEnumerable<>)) return iface.GetGenericArguments()[0];
}
return typeof(object);
}
}
private class WorkerProperty
{
public string PropertyName;
public IList List;
public Type ListPropertyType;
public bool IsArray;
public PropertyInfo ArrayPropertyInfo;
public override string ToString() => PropertyName;
}
}
The workaround can also be as simple as this (supports multi-level JSON as well):
using System;
using System.Linq;
using System.Reflection;
using System.Text.Json.Serialization;
namespace ConsoleApp
{
public class Model
{
public Model()
{
SubModel = new SubModel();
}
public string Title { get; set; }
public string Head { get; set; }
public string Link { get; set; }
public SubModel SubModel { get; set; }
}
public class SubModel
{
public string Name { get; set; }
public string Description { get; set; }
}
class Program
{
static void Main(string[] args)
{
var model = new Model();
Console.WriteLine(JsonSerializer.ToString(model));
var json1 = "{ \"Title\": \"Startpage\", \"Link\": \"/index\" }";
model = Map<Model>(model, json1);
Console.WriteLine(JsonSerializer.ToString(model));
var json2 = "{ \"Head\": \"Latest news\", \"Link\": \"/news\", \"SubModel\": { \"Name\": \"Reyan Chougle\" } }";
model = Map<Model>(model, json2);
Console.WriteLine(JsonSerializer.ToString(model));
var json3 = "{ \"Head\": \"Latest news\", \"Link\": \"/news\", \"SubModel\": { \"Description\": \"I am a Software Engineer\" } }";
model = Map<Model>(model, json3);
Console.WriteLine(JsonSerializer.ToString(model));
var json4 = "{ \"Head\": \"Latest news\", \"Link\": \"/news\", \"SubModel\": { \"Description\": \"I am a Software Programmer\" } }";
model = Map<Model>(model, json4);
Console.WriteLine(JsonSerializer.ToString(model));
Console.ReadKey();
}
public static T Map<T>(T obj, string jsonString) where T : class
{
var newObj = JsonSerializer.Parse<T>(jsonString);
foreach (var property in newObj.GetType().GetProperties())
{
if (obj.GetType().GetProperties().Any(x => x.Name == property.Name && property.GetValue(newObj) != null))
{
if (property.GetType().IsClass && property.PropertyType.Assembly.FullName == typeof(T).Assembly.FullName)
{
MethodInfo mapMethod = typeof(Program).GetMethod("Map");
MethodInfo genericMethod = mapMethod.MakeGenericMethod(property.GetValue(newObj).GetType());
var obj2 = genericMethod.Invoke(null, new object[] { property.GetValue(newObj), JsonSerializer.ToString(property.GetValue(newObj)) });
foreach (var property2 in obj2.GetType().GetProperties())
{
if (property2.GetValue(obj2) != null)
{
property.GetValue(obj).GetType().GetProperty(property2.Name).SetValue(property.GetValue(obj), property2.GetValue(obj2));
}
}
}
else
{
property.SetValue(obj, property.GetValue(newObj));
}
}
}
return obj;
}
}
}
Output:
I do not know much about this new version of the plug-in, however I found a tutorial that can be followed tutorial with some examples
Based on him I thought of this method and I imagine that he is able to solve his problem
//To populate an existing variable we will do so, we will create a variable with the pre existing data
object PrevData = YourVariableData;
//After this we will map the json received
var NewObj = JsonSerializer.Parse<T>(jsonstring);
CopyValues(NewObj, PrevData)
//I found a function that does what you need, you can use it
//source: https://stackoverflow.com/questions/8702603/merging-two-objects-in-c-sharp
public void CopyValues<T>(T target, T source)
{
if (target == null) throw new ArgumentNullException(nameof(target));
if (source== null) throw new ArgumentNullException(nameof(source));
Type t = typeof(T);
var properties = t.GetProperties(
BindingFlags.Instance | BindingFlags.Public).Where(prop =>
prop.CanRead
&& prop.CanWrite
&& prop.GetIndexParameters().Length == 0);
foreach (var prop in properties)
{
var value = prop.GetValue(source, null);
prop.SetValue(target, value, null);
}
}
This code is based on the answer given by V0ldek.
It adds the use of custom converters if they are defined on properties.
Only properties with public Setter are updated.
/// <summary>
/// Utility class for System.Text.Json
/// </summary>
public static class JsonUtility
{
/// <summary>
/// Update an objet from JSON data
/// </summary>
/// <param name="type">Type of the object to update</param>
/// <param name="target">Object to update</param>
/// <param name="jsonSource">JSON Data</param>
/// <remarks>This code is based on the answer given by V0ldek on StackOverflow</remarks>
/// <see cref="https://stackoverflow.com/a/56906228/3216022"/>
public static void PopulateObject(Type type, object target, string jsonSource, JsonSerializerOptions options)
{
var json = JsonDocument.Parse(jsonSource).RootElement;
foreach (var property in json.EnumerateObject())
OverwriteProperty(property);
void OverwriteProperty(JsonProperty updatedProperty)
{
var propertyInfo = type.GetProperty(updatedProperty.Name, BindingFlags.IgnoreCase | BindingFlags.Public | BindingFlags.Instance);
if (!(propertyInfo?.SetMethod?.IsPublic).GetValueOrDefault())
return;
if (propertyInfo.GetCustomAttribute<JsonIgnoreAttribute>() != null)
return;
// If the property has a Converter attribute, we use it
var converter = GetJsonConverter(propertyInfo);
if (converter != null)
{
var serializerOptions = new JsonSerializerOptions(options);
serializerOptions.Converters.Add(converter);
var parsedValue = JsonSerializer.Deserialize(updatedProperty.Value.GetRawText(), propertyInfo.PropertyType, serializerOptions);
propertyInfo.SetValue(target, parsedValue);
}
else
{
var parsedValue = JsonSerializer.Deserialize(updatedProperty.Value.GetRawText(), propertyInfo.PropertyType, options);
propertyInfo.SetValue(target, parsedValue);
}
}
}
/// <summary>
/// Return the JSON Converter of a property (null if not exists)
/// </summary>
/// <param name="propertyInfo">Property</param>
/// <see cref="https://github.com/dotnet/runtime/blob/v6.0.3/src/libraries/System.Text.Json/src/System/Text/Json/Serialization/JsonSerializerOptions.Converters.cs"/>
public static JsonConverter GetJsonConverter(PropertyInfo propertyInfo)
{
var attribute = propertyInfo.GetCustomAttribute<JsonConverterAttribute>();
if (attribute != null)
{
if (attribute.ConverterType == null)
return attribute.CreateConverter(propertyInfo.PropertyType);
else
{
var ctor = attribute.ConverterType.GetConstructor(Type.EmptyTypes);
if (typeof(JsonConverter).IsAssignableFrom(attribute.ConverterType) && (ctor?.IsPublic).GetValueOrDefault())
return (JsonConverter)Activator.CreateInstance(attribute.ConverterType)!;
}
}
return null;
}
}
If you already use AutoMapper in your project or don't mind having dependency on it, you can merge objects in a following way:
var configuration = new MapperConfiguration(cfg => cfg
.CreateMap<Model, Model>()
.ForAllMembers(opts => opts.Condition((src, dest, srcMember) => srcMember != default)));
var mapper = configuration.CreateMapper();
var destination = new Model {Title = "Startpage", Link = "/index"};
var source = new Model {Head = "Latest news", Link = "/news"};
mapper.Map(source, destination);
class Model
{
public string Head { get; set; }
public string Title { get; set; }
public string Link { get; set; }
}
I am not sure if this will fix your problem, but it should work as a temporary workaround. All I did was write a simple class with a populateobject method in it.
public class MyDeserializer
{
public static string PopulateObject(string[] jsonStrings)
{
Dictionary<string, object> fullEntity = new Dictionary<string, object>();
if (jsonStrings != null && jsonStrings.Length > 0)
{
for (int i = 0; i < jsonStrings.Length; i++)
{
var myEntity = JsonSerializer.Parse<Dictionary<string, object>>(jsonStrings[i]);
foreach (var key in myEntity.Keys)
{
if (!fullEntity.ContainsKey(key))
{
fullEntity.Add(key, myEntity[key]);
}
else
{
fullEntity[key] = myEntity[key];
}
}
}
}
return JsonSerializer.ToString(fullEntity);
}
}
I put it into a console app for testing purposes. Below is the entire app if you would like to test it yourself.
using System;
using System.Text.Json;
using System.IO;
using System.Text.Json.Serialization;
namespace JsonQuestion1
{
class Program
{
static void Main(string[] args)
{
// Only used for testing
string path = #"C:\Users\Path\To\JsonFiles";
string st1 = File.ReadAllText(path + #"\st1.json");
string st2 = File.ReadAllText(path + #"\st2.json");
// Only used for testing ^^^
string myObject = MyDeserializer.PopulateObject(new[] { st1, st2 } );
Console.WriteLine(myObject);
Console.ReadLine();
}
}
public class MyDeserializer
{
public static string PopulateObject(string[] jsonStrings)
{
Dictionary<string, object> fullEntity = new Dictionary<string, object>();
if (jsonStrings != null && jsonStrings.Length > 0)
{
for (int i = 0; i < jsonStrings.Length; i++)
{
var myEntity = JsonSerializer.Parse<Dictionary<string, object>>(jsonStrings[i]);
foreach (var key in myEntity.Keys)
{
if (!fullEntity.ContainsKey(key))
{
fullEntity.Add(key, myEntity[key]);
}
else
{
fullEntity[key] = myEntity[key];
}
}
}
}
return JsonSerializer.ToString(fullEntity);
}
}
}
Json File Contents:
st1.json
{
"Title": "Startpage",
"Link": "/index"
}
st2.json
{
"Title": "Startpage",
"Head": "Latest news",
"Link": "/news"
}
If its just one usage and you don't want to add extra dependencies / lots of code, you don't mind a bit of inefficiency and I've not missed something obvious, you can just use:
private static T ParseWithTemplate<T>(T template, string input)
{
var ignoreNulls = new JsonSerializerOptions() { IgnoreNullValues = true };
var templateJson = JsonSerializer.ToString(template, ignoreNulls);
var combinedData = templateJson.TrimEnd('}') + "," + input.TrimStart().TrimStart('{');
return JsonSerializer.Parse<T>(combinedData);
}

JSON string to C# class object [duplicate]

Is there a way to deserialize JSON content into a C# dynamic type? It would be nice to skip creating a bunch of classes in order to use the DataContractJsonSerializer.
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)
It's pretty simple using Json.NET:
dynamic stuff = JsonConvert.DeserializeObject("{ 'Name': 'Jon Smith', 'Address': { 'City': 'New York', 'State': 'NY' }, 'Age': 42 }");
string name = stuff.Name;
string address = stuff.Address.City;
Also using Newtonsoft.Json.Linq:
dynamic stuff = JObject.Parse("{ 'Name': 'Jon Smith', 'Address': { 'City': 'New York', 'State': 'NY' }, 'Age': 42 }");
string name = stuff.Name;
string address = stuff.Address.City;
Documentation: Querying JSON with dynamic
You can do this using System.Web.Helpers.Json - its Decode method returns a dynamic object which you can traverse as you like.
It's included in the System.Web.Helpers assembly (.NET 4.0).
var dynamicObject = Json.Decode(jsonString);
.NET 4.0 has a built-in library to do this:
using System.Web.Script.Serialization;
JavaScriptSerializer jss = new JavaScriptSerializer();
var d = jss.Deserialize<dynamic>(str);
This is the simplest way.
Simple "string JSON data" to object without any third-party DLL file:
WebClient client = new WebClient();
string getString = client.DownloadString("https://graph.facebook.com/zuck");
JavaScriptSerializer serializer = new JavaScriptSerializer();
dynamic item = serializer.Deserialize<object>(getString);
string name = item["name"];
//note: JavaScriptSerializer in this namespaces
//System.Web.Script.Serialization.JavaScriptSerializer
Note: You can also using your custom object.
Personel item = serializer.Deserialize<Personel>(getString);
You can achieve that with the help of Newtonsoft.Json. Install it from NuGet and then:
using Newtonsoft.Json;
dynamic results = JsonConvert.DeserializeObject<dynamic>(YOUR_JSON);
JsonFx can deserialize JSON content into dynamic objects.
Serialize to/from dynamic types (default for .NET 4.0):
var reader = new JsonReader(); var writer = new JsonWriter();
string input = #"{ ""foo"": true, ""array"": [ 42, false, ""Hello!"", null ] }";
dynamic output = reader.Read(input);
Console.WriteLine(output.array[0]); // 42
string json = writer.Write(output);
Console.WriteLine(json); // {"foo":true,"array":[42,false,"Hello!",null]}
Another way using Newtonsoft.Json:
dynamic stuff = Newtonsoft.Json.JsonConvert.DeserializeObject("{ color: 'red', value: 5 }");
string color = stuff.color;
int value = stuff.value;
I came here to find an answer for .NET Core, without any third-party or additional references. It works fine if you use ExpandoObject with the standard JsonSerializer class. Here is the example that worked for me:
using System.Text.Json;
using System.Dynamic;
dynamic json = JsonSerializer.Deserialize<ExpandoObject>(jsonText);
Console.WriteLine(json.name);
This code prints out the string value of a name property that exists within the JSON text passed into the Deserialize method. Voila - no additional libraries, no nothing. Just .NET core.
Edit: May have a problem for several levels of json with nested elements. Worked for a single-level flat object.
I made a new version of the DynamicJsonConverter that uses Expando Objects. I used expando objects, because I wanted to Serialize the dynamic back into JSON using Json.NET.
using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Dynamic;
using System.Web.Script.Serialization;
public static class DynamicJson
{
public static dynamic Parse(string json)
{
JavaScriptSerializer jss = new JavaScriptSerializer();
jss.RegisterConverters(new JavaScriptConverter[] { new DynamicJsonConverter() });
dynamic glossaryEntry = jss.Deserialize(json, typeof(object)) as dynamic;
return glossaryEntry;
}
class DynamicJsonConverter : JavaScriptConverter
{
public override object Deserialize(IDictionary<string, object> dictionary, Type type, JavaScriptSerializer serializer)
{
if (dictionary == null)
throw new ArgumentNullException("dictionary");
var result = ToExpando(dictionary);
return type == typeof(object) ? result : null;
}
private static ExpandoObject ToExpando(IDictionary<string, object> dictionary)
{
var result = new ExpandoObject();
var dic = result as IDictionary<String, object>;
foreach (var item in dictionary)
{
var valueAsDic = item.Value as IDictionary<string, object>;
if (valueAsDic != null)
{
dic.Add(item.Key, ToExpando(valueAsDic));
continue;
}
var arrayList = item.Value as ArrayList;
if (arrayList != null && arrayList.Count > 0)
{
dic.Add(item.Key, ToExpando(arrayList));
continue;
}
dic.Add(item.Key, item.Value);
}
return result;
}
private static ArrayList ToExpando(ArrayList obj)
{
ArrayList result = new ArrayList();
foreach (var item in obj)
{
var valueAsDic = item as IDictionary<string, object>;
if (valueAsDic != null)
{
result.Add(ToExpando(valueAsDic));
continue;
}
var arrayList = item as ArrayList;
if (arrayList != null && arrayList.Count > 0)
{
result.Add(ToExpando(arrayList));
continue;
}
result.Add(item);
}
return result;
}
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) })); }
}
}
}
Creating dynamic objects with Newtonsoft.Json works really great.
//json is your string containing the JSON value
dynamic data = JsonConvert.DeserializeObject<dynamic>(json);
Now you can access the data object just like if it was a regular object. This is the JSON object we currently have as an example:
{ "ID":123,"Name":"Jack","Numbers":[1, 2, 3] }
This is how you access it after deserialization:
data.ID //Retrieve the int
data.Name //Retrieve the string
data.Numbers[0] //Retrieve the first element in the array
I use http://json2csharp.com/ to get a class representing the JSON object.
Input:
{
"name":"John",
"age":31,
"city":"New York",
"Childs":[
{
"name":"Jim",
"age":11
},
{
"name":"Tim",
"age":9
}
]
}
Output:
public class Child
{
public string name { get; set; }
public int age { get; set; }
}
public class Person
{
public string name { get; set; }
public int age { get; set; }
public string city { get; set; }
public List<Child> Childs { get; set; }
}
After that I use Newtonsoft.Json to fill the class:
using Newtonsoft.Json;
namespace GitRepositoryCreator.Common
{
class JObjects
{
public static string Get(object p_object)
{
return JsonConvert.SerializeObject(p_object);
}
internal static T Get<T>(string p_object)
{
return JsonConvert.DeserializeObject<T>(p_object);
}
}
}
You can call it like this:
Person jsonClass = JObjects.Get<Person>(stringJson);
string stringJson = JObjects.Get(jsonClass);
PS:
If your JSON variable name is not a valid C# name (name starts with $) you can fix that like this:
public class Exception
{
[JsonProperty(PropertyName = "$id")]
public string id { get; set; }
public object innerException { get; set; }
public string message { get; set; }
public string typeName { get; set; }
public string typeKey { get; set; }
public int errorCode { get; set; }
public int eventId { get; set; }
}
The simplest way is:
Just include this DLL file.
Use the code like this:
dynamic json = new JDynamic("{a:'abc'}");
// json.a is a string "abc"
dynamic json = new JDynamic("{a:3.1416}");
// json.a is 3.1416m
dynamic json = new JDynamic("{a:1}");
// json.a is
dynamic json = new JDynamic("[1,2,3]");
/json.Length/json.Count is 3
// And you can use json[0]/ json[2] to get the elements
dynamic json = new JDynamic("{a:[1,2,3]}");
//json.a.Length /json.a.Count is 3.
// And you can use json.a[0]/ json.a[2] to get the elements
dynamic json = new JDynamic("[{b:1},{c:1}]");
// json.Length/json.Count is 2.
// And you can use the json[0].b/json[1].c to get the num.
Another option is to "Paste JSON as classes" so it can be deserialised quick and easy.
Simply copy your entire JSON
In Visual Studio: Click Edit → Paste Special → Paste JSON as classes
Here is a better explanation n piccas... ‘Paste JSON As Classes’ in ASP.NET and Web Tools 2012.2 RC
You can extend the JavaScriptSerializer to recursively copy the dictionary it created to expando object(s) and then use them dynamically:
static class JavaScriptSerializerExtensions
{
public static dynamic DeserializeDynamic(this JavaScriptSerializer serializer, string value)
{
var dictionary = serializer.Deserialize<IDictionary<string, object>>(value);
return GetExpando(dictionary);
}
private static ExpandoObject GetExpando(IDictionary<string, object> dictionary)
{
var expando = (IDictionary<string, object>)new ExpandoObject();
foreach (var item in dictionary)
{
var innerDictionary = item.Value as IDictionary<string, object>;
if (innerDictionary != null)
{
expando.Add(item.Key, GetExpando(innerDictionary));
}
else
{
expando.Add(item.Key, item.Value);
}
}
return (ExpandoObject)expando;
}
}
Then you just need to having a using statement for the namespace you defined the extension in (consider just defining them in System.Web.Script.Serialization... another trick is to not use a namespace, then you don't need the using statement at all) and you can consume them like so:
var serializer = new JavaScriptSerializer();
var value = serializer.DeserializeDynamic("{ 'Name': 'Jon Smith', 'Address': { 'City': 'New York', 'State': 'NY' }, 'Age': 42 }");
var name = (string)value.Name; // Jon Smith
var age = (int)value.Age; // 42
var address = value.Address;
var city = (string)address.City; // New York
var state = (string)address.State; // NY
You can use using Newtonsoft.Json
var jRoot =
JsonConvert.DeserializeObject<dynamic>(Encoding.UTF8.GetString(resolvedEvent.Event.Data));
resolvedEvent.Event.Data is my response getting from calling core Event .
Try this:
var units = new { Name = "Phone", Color= "White" };
var jsonResponse = JsonConvert.DeserializeAnonymousType(json, units);
I am using like this in my code and it's working fine
using System.Web.Script.Serialization;
JavaScriptSerializer oJS = new JavaScriptSerializer();
RootObject oRootObject = new RootObject();
oRootObject = oJS.Deserialize<RootObject>(Your JSon String);
Look at the article I wrote on CodeProject, one that answers the question precisely:
Dynamic types with JSON.NET
There is way too much for re-posting it all here, and even less point since that article has an attachment with the key/required source file.
For that I would use JSON.NET to do the low-level parsing of the JSON stream and then build up the object hierarchy out of instances of the ExpandoObject class.
To get an ExpandoObject:
using Newtonsoft.Json;
using Newtonsoft.Json.Converters;
Container container = JsonConvert.Deserialize<Container>(jsonAsString, new ExpandoObjectConverter());
Deserializing in JSON.NET can be dynamic using the JObject class, which is included in that library. My JSON string represents these classes:
public class Foo {
public int Age {get;set;}
public Bar Bar {get;set;}
}
public class Bar {
public DateTime BDay {get;set;}
}
Now we deserialize the string WITHOUT referencing the above classes:
var dyn = JsonConvert.DeserializeObject<JObject>(jsonAsFooString);
JProperty propAge = dyn.Properties().FirstOrDefault(i=>i.Name == "Age");
if(propAge != null) {
int age = int.Parse(propAge.Value.ToString());
Console.WriteLine("age=" + age);
}
//or as a one-liner:
int myage = int.Parse(dyn.Properties().First(i=>i.Name == "Age").Value.ToString());
Or if you want to go deeper:
var propBar = dyn.Properties().FirstOrDefault(i=>i.Name == "Bar");
if(propBar != null) {
JObject o = (JObject)propBar.First();
var propBDay = o.Properties().FirstOrDefault (i => i.Name=="BDay");
if(propBDay != null) {
DateTime bday = DateTime.Parse(propBDay.Value.ToString());
Console.WriteLine("birthday=" + bday.ToString("MM/dd/yyyy"));
}
}
//or as a one-liner:
DateTime mybday = DateTime.Parse(((JObject)dyn.Properties().First(i=>i.Name == "Bar").First()).Properties().First(i=>i.Name == "BDay").Value.ToString());
See post for a complete example.
The object you want DynamicJSONObject is included in the System.Web.Helpers.dll from the ASP.NET Web Pages package, which is part of WebMatrix.
There is a lightweight JSON library for C# called SimpleJson.
It supports .NET 3.5+, Silverlight and Windows Phone 7.
It supports dynamic for .NET 4.0
It can also be installed as a NuGet package
Install-Package SimpleJson
Use DataSet(C#) with JavaScript. A simple function for creating a JSON stream with DataSet input. Create JSON content like (multi table dataset):
[[{a:1,b:2,c:3},{a:3,b:5,c:6}],[{a:23,b:45,c:35},{a:58,b:59,c:45}]]
Just client side, use eval. For example,
var d = eval('[[{a:1,b:2,c:3},{a:3,b:5,c:6}],[{a:23,b:45,c:35},{a:58,b:59,c:45}]]')
Then use:
d[0][0].a // out 1 from table 0 row 0
d[1][1].b // out 59 from table 1 row 1
// Created by Behnam Mohammadi And Saeed Ahmadian
public string jsonMini(DataSet ds)
{
int t = 0, r = 0, c = 0;
string stream = "[";
for (t = 0; t < ds.Tables.Count; t++)
{
stream += "[";
for (r = 0; r < ds.Tables[t].Rows.Count; r++)
{
stream += "{";
for (c = 0; c < ds.Tables[t].Columns.Count; c++)
{
stream += ds.Tables[t].Columns[c].ToString() + ":'" +
ds.Tables[t].Rows[r][c].ToString() + "',";
}
if (c>0)
stream = stream.Substring(0, stream.Length - 1);
stream += "},";
}
if (r>0)
stream = stream.Substring(0, stream.Length - 1);
stream += "],";
}
if (t>0)
stream = stream.Substring(0, stream.Length - 1);
stream += "];";
return stream;
}
How to parse easy JSON content with dynamic & JavaScriptSerializer
Please add reference of System.Web.Extensions and add this namespace using System.Web.Script.Serialization; at top:
public static void EasyJson()
{
var jsonText = #"{
""some_number"": 108.541,
""date_time"": ""2011-04-13T15:34:09Z"",
""serial_number"": ""SN1234""
}";
var jss = new JavaScriptSerializer();
var dict = jss.Deserialize<dynamic>(jsonText);
Console.WriteLine(dict["some_number"]);
Console.ReadLine();
}
How to parse nested & complex json with dynamic & JavaScriptSerializer
Please add reference of System.Web.Extensions and add this namespace using System.Web.Script.Serialization; at top:
public static void ComplexJson()
{
var jsonText = #"{
""some_number"": 108.541,
""date_time"": ""2011-04-13T15:34:09Z"",
""serial_number"": ""SN1234"",
""more_data"": {
""field1"": 1.0,
""field2"": ""hello""
}
}";
var jss = new JavaScriptSerializer();
var dict = jss.Deserialize<dynamic>(jsonText);
Console.WriteLine(dict["some_number"]);
Console.WriteLine(dict["more_data"]["field2"]);
Console.ReadLine();
}
I want to do this programmatically in unit tests, I do have the luxury of typing it out.
My solution is:
var dict = JsonConvert.DeserializeObject<ExpandoObject>(json) as IDictionary<string, object>;
Now I can assert that
dict.ContainsKey("ExpectedProperty");
With Cinchoo ETL - an open source library available to parse JSON into a dynamic object:
string json = #"{
""key1"": [
{
""action"": ""open"",
""timestamp"": ""2018-09-05 20:46:00"",
""url"": null,
""ip"": ""66.102.6.98""
}
]
}";
using (var p = ChoJSONReader.LoadText(json)
.WithJSONPath("$..key1")
)
{
foreach (var rec in p)
{
Console.WriteLine("Action: " + rec.action);
Console.WriteLine("Timestamp: " + rec.timestamp);
Console.WriteLine("URL: " + rec.url);
Console.WriteLine("IP address: " + rec.ip);
}
}
Output:
Action: open
Timestamp: 2018-09-05 20:46:00
URL: http://www.google.com
IP address: 66.102.6.98
Sample fiddle: https://dotnetfiddle.net/S0ehSV
For more information, please visit codeproject articles
Disclaimer: I'm the author of this library.
try this way!
JSON example:
[{
"id": 140,
"group": 1,
"text": "xxx",
"creation_date": 123456,
"created_by": "xxx#gmail.co",
"tags": ["xxxxx"]
}, {
"id": 141,
"group": 1,
"text": "xxxx",
"creation_date": 123456,
"created_by": "xxx#gmail.com",
"tags": ["xxxxx"]
}]
C# code:
var jsonString = (File.ReadAllText(Path.Combine(Directory.GetCurrentDirectory(),"delete_result.json")));
var objects = JsonConvert.DeserializeObject<dynamic>(jsonString);
foreach(var o in objects)
{
Console.WriteLine($"{o.id.ToString()}");
}
I really like System.Web.Helpers,
dynamic data = Json.Decode(json);
as it supports usage like
var val = data.Members.NumberTen;
or
var val data.Members["10"];
The reference to System.Web.Helpers.DLL is really crazy, it is not even console and desktop app friendly. Here is my attempt to extract the same functionalities as a standalone file directly from https://github.com/mono/aspnetwebstack/tree/master/src/System.Web.Helpers
(Share this as for education purpose only)
// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information.
using System.Collections.Generic;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.Dynamic;
using System.Linq.Expressions;
using System.Runtime.CompilerServices;
using Microsoft.CSharp.RuntimeBinder;
using System.Web.Script.Serialization;
using System.IO;
using System.Collections;
using System.Linq;
using System.Globalization;
namespace System.Web.Helpers
{
public static class Json
{
private static readonly JavaScriptSerializer _serializer = CreateSerializer();
public static string Encode(object value)
{
// Serialize our dynamic array type as an array
DynamicJsonArray jsonArray = value as DynamicJsonArray;
if (jsonArray != null)
{
return _serializer.Serialize((object[])jsonArray);
}
return _serializer.Serialize(value);
}
public static void Write(object value, TextWriter writer)
{
writer.Write(_serializer.Serialize(value));
}
public static dynamic Decode(string value)
{
return WrapObject(_serializer.DeserializeObject(value));
}
public static dynamic Decode(string value, Type targetType)
{
return WrapObject(_serializer.Deserialize(value, targetType));
}
public static T Decode<T>(string value)
{
return _serializer.Deserialize<T>(value);
}
private static JavaScriptSerializer CreateSerializer()
{
JavaScriptSerializer serializer = new JavaScriptSerializer();
serializer.RegisterConverters(new[] { new DynamicJavaScriptConverter() });
return serializer;
}
internal class DynamicJavaScriptConverter : JavaScriptConverter
{
public override IEnumerable<Type> SupportedTypes
{
get
{
yield return typeof(IDynamicMetaObjectProvider);
yield return typeof(DynamicObject);
}
}
public override object Deserialize(IDictionary<string, object> dictionary, Type type, JavaScriptSerializer serializer)
{
throw new NotSupportedException();
}
public override IDictionary<string, object> Serialize(object obj, JavaScriptSerializer serializer)
{
Dictionary<string, object> dictionary = new Dictionary<string, object>(StringComparer.OrdinalIgnoreCase);
IEnumerable<string> memberNames = DynamicHelper.GetMemberNames(obj);
foreach (string item in memberNames)
{
dictionary[item] = DynamicHelper.GetMemberValue(obj, item);
}
return dictionary;
}
}
internal static dynamic WrapObject(object value)
{
// The JavaScriptSerializer returns IDictionary<string, object> for objects
// and object[] for arrays, so we wrap those in different dynamic objects
// so we can access the object graph using dynamic
var dictionaryValues = value as IDictionary<string, object>;
if (dictionaryValues != null)
{
return new DynamicJsonObject(dictionaryValues);
}
var arrayValues = value as object[];
if (arrayValues != null)
{
return new DynamicJsonArray(arrayValues);
}
return value;
}
}
// REVIEW: Consider implementing ICustomTypeDescriptor and IDictionary<string, object>
public class DynamicJsonObject : DynamicObject
{
private readonly IDictionary<string, object> _values;
public DynamicJsonObject(IDictionary<string, object> values)
{
Debug.Assert(values != null);
_values = values.ToDictionary(p => p.Key, p => Json.WrapObject(p.Value),
StringComparer.OrdinalIgnoreCase);
}
public override bool TryConvert(ConvertBinder binder, out object result)
{
result = null;
if (binder.Type.IsAssignableFrom(_values.GetType()))
{
result = _values;
}
else
{
throw new InvalidOperationException(String.Format(CultureInfo.CurrentCulture, "HelpersResources.Json_UnableToConvertType", binder.Type));
}
return true;
}
public override bool TryGetMember(GetMemberBinder binder, out object result)
{
result = GetValue(binder.Name);
return true;
}
public override bool TrySetMember(SetMemberBinder binder, object value)
{
_values[binder.Name] = Json.WrapObject(value);
return true;
}
public override bool TrySetIndex(SetIndexBinder binder, object[] indexes, object value)
{
string key = GetKey(indexes);
if (!String.IsNullOrEmpty(key))
{
_values[key] = Json.WrapObject(value);
}
return true;
}
public override bool TryGetIndex(GetIndexBinder binder, object[] indexes, out object result)
{
string key = GetKey(indexes);
result = null;
if (!String.IsNullOrEmpty(key))
{
result = GetValue(key);
}
return true;
}
private static string GetKey(object[] indexes)
{
if (indexes.Length == 1)
{
return (string)indexes[0];
}
// REVIEW: Should this throw?
return null;
}
public override IEnumerable<string> GetDynamicMemberNames()
{
return _values.Keys;
}
private object GetValue(string name)
{
object result;
if (_values.TryGetValue(name, out result))
{
return result;
}
return null;
}
}
[SuppressMessage("Microsoft.Naming", "CA1710:IdentifiersShouldHaveCorrectSuffix", Justification = "This class isn't meant to be used directly")]
public class DynamicJsonArray : DynamicObject, IEnumerable<object>
{
private readonly object[] _arrayValues;
public DynamicJsonArray(object[] arrayValues)
{
Debug.Assert(arrayValues != null);
_arrayValues = arrayValues.Select(Json.WrapObject).ToArray();
}
public int Length
{
get { return _arrayValues.Length; }
}
public dynamic this[int index]
{
get { return _arrayValues[index]; }
set { _arrayValues[index] = Json.WrapObject(value); }
}
public override bool TryConvert(ConvertBinder binder, out object result)
{
if (_arrayValues.GetType().IsAssignableFrom(binder.Type))
{
result = _arrayValues;
return true;
}
return base.TryConvert(binder, out result);
}
public override bool TryGetMember(GetMemberBinder binder, out object result)
{
// Testing for members should never throw. This is important when dealing with
// services that return different json results. Testing for a member shouldn't throw,
// it should just return null (or undefined)
result = null;
return true;
}
public IEnumerator GetEnumerator()
{
return _arrayValues.GetEnumerator();
}
private IEnumerable<object> GetEnumerable()
{
return _arrayValues.AsEnumerable();
}
IEnumerator<object> IEnumerable<object>.GetEnumerator()
{
return GetEnumerable().GetEnumerator();
}
[SuppressMessage("Microsoft.Usage", "CA2225:OperatorOverloadsHaveNamedAlternates", Justification = "This class isn't meant to be used directly")]
public static implicit operator object[](DynamicJsonArray obj)
{
return obj._arrayValues;
}
[SuppressMessage("Microsoft.Usage", "CA2225:OperatorOverloadsHaveNamedAlternates", Justification = "This class isn't meant to be used directly")]
public static implicit operator Array(DynamicJsonArray obj)
{
return obj._arrayValues;
}
}
/// <summary>
/// Helper to evaluate different method on dynamic objects
/// </summary>
public static class DynamicHelper
{
// We must pass in "object" instead of "dynamic" for the target dynamic object because if we use dynamic, the compiler will
// convert the call to this helper into a dynamic expression, even though we don't need it to be. Since this class is internal,
// it cannot be accessed from a dynamic expression and thus we get errors.
// Dev10 Bug 914027 - Changed the first parameter from dynamic to object, see comment at top for details
public static bool TryGetMemberValue(object obj, string memberName, out object result)
{
try
{
result = GetMemberValue(obj, memberName);
return true;
}
catch (RuntimeBinderException)
{
}
catch (RuntimeBinderInternalCompilerException)
{
}
// We catch the C# specific runtime binder exceptions since we're using the C# binder in this case
result = null;
return false;
}
// Dev10 Bug 914027 - Changed the first parameter from dynamic to object, see comment at top for details
[SuppressMessage("Microsoft.Design", "CA1031:DoNotCatchGeneralExceptionTypes", Justification = "We want to swallow exceptions that happen during runtime binding")]
public static bool TryGetMemberValue(object obj, GetMemberBinder binder, out object result)
{
try
{
// VB us an instance of GetBinderAdapter that does not implement FallbackGetMemeber. This causes lookup of property expressions on dynamic objects to fail.
// Since all types are private to the assembly, we assume that as long as they belong to CSharp runtime, it is the right one.
if (typeof(Binder).Assembly.Equals(binder.GetType().Assembly))
{
// Only use the binder if its a C# binder.
result = GetMemberValue(obj, binder);
}
else
{
result = GetMemberValue(obj, binder.Name);
}
return true;
}
catch
{
result = null;
return false;
}
}
// Dev10 Bug 914027 - Changed the first parameter from dynamic to object, see comment at top for details
public static object GetMemberValue(object obj, string memberName)
{
var callSite = GetMemberAccessCallSite(memberName);
return callSite.Target(callSite, obj);
}
// Dev10 Bug 914027 - Changed the first parameter from dynamic to object, see comment at top for details
public static object GetMemberValue(object obj, GetMemberBinder binder)
{
var callSite = GetMemberAccessCallSite(binder);
return callSite.Target(callSite, obj);
}
// dynamic d = new object();
// object s = d.Name;
// The following code gets generated for this expression:
// callSite = CallSite<Func<CallSite, object, object>>.Create(Binder.GetMember(CSharpBinderFlags.None, "Name", typeof(Program), new CSharpArgumentInfo[] { CSharpArgumentInfo.Create(CSharpArgumentInfoFlags.None, null) }));
// callSite.Target(callSite, d);
// typeof(Program) is the containing type of the dynamic operation.
// Dev10 Bug 914027 - Changed the callsite's target parameter from dynamic to object, see comment at top for details
public static CallSite<Func<CallSite, object, object>> GetMemberAccessCallSite(string memberName)
{
var binder = Binder.GetMember(CSharpBinderFlags.None, memberName, typeof(DynamicHelper), new[] { CSharpArgumentInfo.Create(CSharpArgumentInfoFlags.None, null) });
return GetMemberAccessCallSite(binder);
}
// Dev10 Bug 914027 - Changed the callsite's target parameter from dynamic to object, see comment at top for details
public static CallSite<Func<CallSite, object, object>> GetMemberAccessCallSite(CallSiteBinder binder)
{
return CallSite<Func<CallSite, object, object>>.Create(binder);
}
// Dev10 Bug 914027 - Changed the first parameter from dynamic to object, see comment at top for details
public static IEnumerable<string> GetMemberNames(object obj)
{
var provider = obj as IDynamicMetaObjectProvider;
Debug.Assert(provider != null, "obj doesn't implement IDynamicMetaObjectProvider");
Expression parameter = Expression.Parameter(typeof(object));
return provider.GetMetaObject(parameter).GetDynamicMemberNames();
}
}
}

How to ignore empty object literals in the produced JSON?

I'm using Json.NET to convert a complex C# object graph to JSON. Due to ignoring properties which have default values in the object, I usually get empty object literals in the output, which I'd like to omit.
For example:
public class Sample {
public int Value { get; set; }
public string Name { get; set; }
}
public class ParentSample {
// this property should never be null, hence the initializer
public Sample Sample { get; } = new Sample();
}
..
var obj = new ParentSample();
// settings for indentation and excluding default values omitted for clarity
var output = JsonConvert.SerializeObject(obj, ... );
// output will be
// {
// Sample: {}
// }
//
// I'd like it to be
// {}
I'm aware of some type specific solutions like adding a ShouldSerializeSample boolean method to the ParentSample type and check if all properties are default there. However I'd like a general solution in the form of a custom contract resolver for example.
In the comments it looks like you have decided to resort to using Regex to get rid of the empty objects. One problem with that idea is it probably will not handle the situation where you have what I will call "recursive empty objects". In other words something like this:
{
"foo":
{
"bar": {},
"baz": {}
}
}
If you manage to remove the deepest level empty objects bar and baz with Regex (while also realizing that you need to remove the comma between them to keep the JSON valid), you will still have an empty object left: foo.
{
"foo":
{
}
}
I think a better solution is to load your data into a JToken hierarchy and then use a recursive method to remove all the empty children before writing it out to JSON. Something like this should work for your needs:
using System;
using Newtonsoft.Json.Linq;
public static class JsonHelper
{
public static string SerializeToMinimalJson(object obj)
{
return JToken.FromObject(obj).RemoveEmptyChildren().ToString();
}
public static JToken RemoveEmptyChildren(this JToken token)
{
if (token.Type == JTokenType.Object)
{
JObject copy = new JObject();
foreach (JProperty prop in token.Children<JProperty>())
{
JToken child = prop.Value;
if (child.HasValues)
{
child = child.RemoveEmptyChildren();
}
if (!child.IsEmptyOrDefault())
{
copy.Add(prop.Name, child);
}
}
return copy;
}
else if (token.Type == JTokenType.Array)
{
JArray copy = new JArray();
foreach (JToken item in token.Children())
{
JToken child = item;
if (child.HasValues)
{
child = child.RemoveEmptyChildren();
}
if (!child.IsEmptyOrDefault())
{
copy.Add(child);
}
}
return copy;
}
return token;
}
public static bool IsEmptyOrDefault(this JToken token)
{
return (token.Type == JTokenType.Array && !token.HasValues) ||
(token.Type == JTokenType.Object && !token.HasValues) ||
(token.Type == JTokenType.String && token.ToString() == String.Empty) ||
(token.Type == JTokenType.Boolean && token.Value<bool>() == false) ||
(token.Type == JTokenType.Integer && token.Value<int>() == 0) ||
(token.Type == JTokenType.Float && token.Value<double>() == 0.0) ||
(token.Type == JTokenType.Null);
}
}
You can then serialize your object(s) like this:
var json = JsonHelper.SerializeToMinimalJson(obj);
Fiddle: https://dotnetfiddle.net/awRPMR
EDIT
If you want to honor the [DefaultValue] attribute with this method, you can do so by modifying the SerializeToMinimalJson() method to create an instance of the JsonSerializer, setting the DefaultValueHandling property on it, and then passing it to JToken.FromObject() as shown below. (It has to be done this way because JTokens do not have references back to the original objects from which they were created using FromObject(), so there's no way to get the values of the [DefaultValue] attributes after that.)
public static string SerializeToMinimalJson(object obj)
{
var serializer = new JsonSerializer();
serializer.NullValueHandling = NullValueHandling.Ignore;
serializer.DefaultValueHandling = DefaultValueHandling.Ignore;
return JToken.FromObject(obj, serializer).RemoveEmptyChildren().ToString();
}
If you do that, you may also want to change the IsEmptyOrDefault() method so that it does not remove values that are the "default default". You can reduce it to this:
public static bool IsEmptyOrDefault(this JToken token)
{
return (token.Type == JTokenType.Array && !token.HasValues) ||
(token.Type == JTokenType.Object && !token.HasValues);
}
Fiddle: https://dotnetfiddle.net/0yVRI5
I implemented a slightly different solution which uses a generic method, reflection and some default Newtonsoft.Json ShouldSerialize functionality. Not elegant but conceptually simple for my particular need. Below is the LinqPad code snippet.
void Main()
{
Person person = new Person();
person.MyAddress = new Address();
var ret = person.ShouldSerializeMyAddress();
var json = JsonConvert.SerializeObject(person, Newtonsoft.Json.Formatting.Indented, new JsonSerializerSettings
{
NullValueHandling = NullValueHandling.Ignore
});
json.Dump();
}
public static class JsonExtensions
{
public static bool ShouldSerialize(this object self)
{
if (self == null)
return false;
var methods = self.GetType().GetMethods().Where(p => p.Name.StartsWith("ShouldSerialize"));
return methods.Any(p => p.Invoke(self, null) is bool value && value);
}
}
public class Person
{
public Address MyAddress { get; set; }
public bool ShouldSerializeMyAddress()
{
return MyAddress.ShouldSerialize();
}
}
public class Address
{
public string Street { get; set; }
public bool ShouldSerializeStreet()
{
return false; // or whatever your property serialization criteria should be
}
public string City { get; set; }
public bool ShouldSerializeCity()
{
return false;
}
public string State { get; set; }
public bool ShouldSerializeState()
{
return false;
}
public string Zip { get; set; }
public bool ShouldSerializeZip()
{
return false;
}
}
You can give a JsonSerializerSettings to the method using NullValueHandling.Ignore:
var output = JsonConvert.SerializeObject(obj, new JsonSerializerSettings
{
NullValueHandling = NullValueHandling.Ignore
});
If this settings doesn't give what you need, check: the documentation. There you can find all the properties and a description.
Edit: Using the child (Sample) as struct it works with DefaultValueHandling.Ignore. But #Zoltán Tamási will use a regex due to the class complexity.

How to parse JSON to a dynamic object on Windows Phone 7?

For web applications I can use System.Web and use this trick to convert JSON to a dynamic object.
But for Windows Phone I can't use JavaScriptConverter. What is the workaround to convert JSON in a dynamic object on Windows Phone 7.1?
Json.Net ( http://james.newtonking.com/pages/json-net.aspx )
-----EDIT-----
If WP7 supports DynamicObject:
using System;
using System.Dynamic;
using System.Collections;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
public class JSonTest
{
public static void Main()
{
string jsonStr = #"
{
'glossary': {
'title': 'example glossary',
'GlossDiv': {
'title': 'S',
'GlossList': {
'GlossEntry': {
'ID': 'SGML',
'SortAs': 'SGML',
'GlossTerm': 'Standard Generalized Markup Language',
'Acronym': 'SGML',
'Abbrev': 'ISO 8879:1986',
'GlossDef': {
'para': 'A meta-markup language, used to create markup languages such as DocBook.',
'GlossSeeAlso': ['GML','XML']
},
'GlossSee': 'markup'
}
}
}
}
}
";
JObject o = (JObject)JsonConvert.DeserializeObject(jsonStr);
dynamic json = new JsonObject(o);
Console.WriteLine(json.glossary.GlossDiv.GlossList.GlossEntry.GlossDef.GlossSeeAlso.Length);
Console.WriteLine(json.glossary.GlossDiv.GlossList.GlossEntry.GlossDef.GlossSeeAlso[1]);
foreach (var x in json.glossary.GlossDiv.GlossList.GlossEntry.GlossDef.GlossSeeAlso)
{
Console.WriteLine(x);
}
Console.ReadLine();
}
}
class JsonObject : DynamicObject,IEnumerable,IEnumerator
{
object _object;
public JsonObject(object jObject)
{
this._object = jObject;
}
public object this[int i]
{
get
{
if (!(_object is JArray)) return null;
object obj = (_object as JArray)[i];
if (obj is JValue)
{
return ((JValue)obj).ToString();
}
return new JsonObject(obj);
}
}
public override bool TryGetMember(GetMemberBinder binder, out object result)
{
result = null;
if (_object is JArray && binder.Name == "Length")
{
result = (_object as JArray).Count;
return true;
}
JObject jObject = _object as JObject;
object obj = jObject.SelectToken(binder.Name);
if (obj is JValue)
result = ((JValue)obj).ToString();
else
result = new JsonObject(jObject.SelectToken(binder.Name));
return true;
}
public override string ToString()
{
return _object.ToString();
}
int _index = -1;
public IEnumerator GetEnumerator()
{
_index = -1;
return this;
}
public object Current
{
get
{
if (!(_object is JArray)) return null;
object obj = (_object as JArray)[_index];
if (obj is JValue) return ((JValue)obj).ToString();
return obj;
}
}
public bool MoveNext()
{
if (!(_object is JArray)) return false;
_index++;
return _index <(_object as JArray).Count;
}
public void Reset()
{
throw new NotImplementedException();
}
}

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