Newtonsoft deserialize object that extends from Collection<Item> - c#

I'm trying to use NewtonSoft.Json deserializer, but I don't know if what I'm trying to do is doable, cuase every example of collections that I've seen are like this:
public class ItemRecords
{
public List<ItemRecords> Items { get; set; }
...
}
And what I want is something that looks like as it's explained below...
I have this two classes:
public class ItemRecords : Collection<ItemRecord>
{
[JsonProperty("property1")]
public int Property1 { get; set; }
[JsonProperty("property2")]
public int Property2 { get; set; }
}
public class ItemRecord
{
[JsonProperty("id")]
public int Id { get; set; }
[JsonProperty("item_prop1")]
public string ItemProp1 { get; set; }
...
}
I get this json back from my api:
{
property1: 25,
property2: 27,
item_record: [
{
id: 241,
item_prop1: "0.132",
item_prop2: "78787",
...
},
{
id: 242
item_prop1: "1212",
item_prop2: "3333",
...
}
...
]
}
ItemRecords is a collection of ItemRecord.
I tried by adding the JsonArray attribute to the ItemRecords class as follows:
[JsonArray(ItemConverterType = typeof(ItemRecord))]
public class ItemRecords : Collection<ItemRecord> { ... }
Here is the method that executes the request:
private static async Task<T> MakeRequest<T>(string urlRequest)
{
try
{
HttpWebRequest request = WebRequest.Create(urlRequest) as HttpWebRequest;
using (WebResponse response = await request.GetResponseAsync())
{
using (Stream stream = response.GetResponseStream())
{
StreamReader reader = new StreamReader(stream);
string line = string.Empty;
StringBuilder sb = new StringBuilder();
while ((line = reader.ReadLine()) != null)
{
sb.Append(line);
}
T objectDeserialized = JsonConvert.DeserializeObject<T>(sb.ToString());
return objectDeserialized;
}
}
}
catch (Exception ex)
{
return default(T);
}
}
And call to this method looks like this:
...
return await MakeRequest<ItemRecords>(request);
I don't really know what else to do..
Any help would be appreciated.

Your basic difficulty is that the JSON standard has two types of container:
The object which is an unordered set of name/value pairs. An object begins with { (left brace) and ends with } (right brace). Json.NET maps dictionaries and non-enumerable POCOS to objects by default, using reflection to map c# properties to JSON properties.
In the JSON you are getting back from your API, the outermost container is an object.
The array which is an ordered collection of values. An array begins with [ (left bracket) and ends with ] (right bracket). Values are separated by , (comma). Json.NET maps non-dictionary enumerables to arrays by default, serializing each collection item as an array entry.
In the JSON you are getting back from your API, the value of the item_record property is an array.
As a collection with properties, your ItemRecords cannot be mapped to either of these constructs automatically without losing data. Since Json.NET serializes collections as arrays by default, you will need to manually inform it that your type is to be serialized as an object by applying the [JsonObject] attribute. Then, introduce a synthetic item_record property to serialize and deserialize the collection items. Since you are inheriting from Collection<T>, you can use Collection<T>.Items for this purpose:
[JsonObject(MemberSerialization.OptIn)]
public class ItemRecords : Collection<ItemRecord>
{
[JsonProperty("property1")]
public int Property1 { get; set; }
[JsonProperty("property2")]
public int Property2 { get; set; }
[JsonProperty("item_record")]
IList<ItemRecord> ItemRecordList
{
get
{
return Items;
}
}
}
Using MemberSerialization.OptIn prevents base class properties such as Count from being serialized.
Sample fiddle.
As an aside, I don't particularly recommend this design, as it can cause problems with other serializers. For instance, XmlSerializer will never serialize collection properties; see here or here. See also Why not inherit from List?.

Simply add a List<ItemRecord> Records property to class ItemRecords:
public class ItemRecords
{
[JsonProperty("property1")]
public int Property1 { get; set; }
[JsonProperty("property2")]
public int Property2 { get; set; }
[JsonProperty("item_record")]
public List<ItemRecord> Records { get; set; }
}

This looks like you can have a dynamic number of results of properties and item properties like:
{
property1: 25,
property2: 27,
property3: 30,
item_record: [
{
id: 241,
item_prop1: "0.132",
item_prop2: "78787"
},
{
id: 242
item_prop1: "1212",
item_prop2: "3333",
item_prop3: "3333",
item_prop4: "3333",
}
] }
If this is the case, the best option in my opinion will be to change the structure to something like:
{
properties:[
25,
27,
30
],
itemRecords:[
{
id: 27,
itemProperties:[
"321",
"654",
"564"
]
},
{
id: 25,
itemProperties:[
"321",
"654"
]
},
]
}

Related

Derserialize JSON.NET With Unknown RootObject Key

{
"578080": {
"success": true,
"data": {
"type": "game",
"name": "PLAYERUNKNOWN'S BATTLEGROUNDS",
"steam_appid": 578080,
"required_age": 0,
"is_free": false,
}
}
}
This is from the Steam API. As you can see the root key the ID itself, so I don't know how to deserialize this to an object. I've seen other questions regarding unknown property names, but can't seem to apply those solutions for when the root name is unknown.
One way to do this is to Deserialize to Dictionary
Classes
public class Data
{
public string type { get; set; }
public string name { get; set; }
public int steam_appid { get; set; }
public int required_age { get; set; }
public bool is_free { get; set; }
}
public class SomeClass
{
public bool success { get; set; }
public Data data { get; set; }
}
Usage
var result = JsonConvert.DeserializeObject<Dictionary<string, SomeClass>>(json);
If you don't care about making POCO models for your deserialized data and just want to grab some of the properties using a dynamic, you can use JsonExtensionData to get a JToken of the relevant subobject:
public class Foo
{
[JsonExtensionData]
public Dictionary<string, JToken> ExtensionData {get; set;}
}
dynamic obj = JsonConvert.DeserializeObject<Foo>(json).ExtensionData.Single().Value;
Console.WriteLine(obj.success);
Console.WriteLine(obj.data.name);
This approach would be particularly useful if you could reuse Foo across several different types of responses since it doesn't care at all about the object schema.
You can use an anonymous type deserialization to parse JSON data like this, without creating classes. I assumed there is only one Id("578080") present in your data.If more Id's present, you can create an array for those Id's. Hope It Works.
var finalResult=JsonConvert.DeserializeAnonymousType(
yourdata, // input
new
{
Id=
{
new
{
success="", data=""
}
}
}
);
console.write(finalResult.Id);// getting Id 578080
console.write(finalResult.Id.success);
console.write(finalResult.Id.data.type);

GetSet nested property

Having trouble accessing a response back from a rest API service that has nested property.
For example here's the raw REST response:
"count": 5,
"results": [
{
"suggestion": "1 Wonston Road, Southampton, SO16 ...",
"matched": [[ 29, 37 ]],
{
"suggestion": "3 Wonston Road, Southampton, SO16 ...",
"matched": [[ 29, 37 ]],
Suggestion and Match are nested property within results.
The function that gets the response in my code is
IRestResponse<SearchResponse> response = client.Execute<SearchResponse>(request); I've used rest sharp here and the call is actually accurate as I get all the data back in form of a raw response.
I've defined the SearchResponse class as
//same for result, match, suggestion.
private string _count;
public string Count
{
get
{
return _count;
}
set
{
_count = value;
}
}
How can I define nested variables to pass them into SearchResponse.suggestion? Currently the nested properties are stored in results.
public class Result {
public string suggestion { get; set; }
public List<List<int>> matched { get; set; }
public string format { get; set; } }
public class RootObject {
public int count { get; set; }
public List<Result> results { get; set; } }
http://json2csharp.com Did the trick, Thank you

How to parse json with different key names and similar objects in each key?

I have this JSON :
{
"response": {
"PEOPLE": {
"PERSON1": {
"name": "jon",
"last": "jony"
},
"PERSON2": {
"name": "mike",
"last": "mikey"
}
}
}
}
How can I parse it to a dictionary which the key will be the PERSONX string?
I'm new to c#, and know that in Java I need to have one class, where internal key will be : "person_name"...
I suggest create a class because it's easier to work and you have full control of it.
public class Response
{
public Dictionary<string,Person> People{ get; set; }
}
public class Person
{
public string Name { get; set; }
public string Last { get; set; }
}
When properties have different names I use Dictionary and then you can use LINQ to access them.
Get value of a dictionary:
var valueOfFirstPeopleElement = People.FirstOrDefault().Value;
This way you have the person class.
In order to parse the json to this class you must deserialize using a json converter.
Response response = JsonConvert.DeserializeObject<Response>(jsonData);
To do the reverse you Serialize instead.
string jsonData = JsonConvert.SerializeObject(response);

Accessing subfields in json file

Assuming I have a JSON file with the following structure. How I can access the names of the properties in the metadata field.
{
"mappings": {
"basedoc_12kja": {
"properties": {
"created": {
"type": "date",
"format": "dateOptionalTime"
},
"customerID": {
"type": "string"
},
"deleted": {
"type": "boolean"
},
"documentID": {
"type": "string"
},
"id": {
"type": "string"
},
"metadata": {
"properties": {
"Cert": {
"type": "string"
},
"Exp_date": {
"format": "dateOptionalTime"
},
}
}
}
}
}
}
Mappings is an array of documents, each subfield of mappings has a different code. I want to obtain the metadata fields of each document to find out which metadata fields are common between them.
I haven't been able to instantiate this documents.
var response = esReader.GetIndicesMapping();
foreach (var mapping in response.Response.Values)
{
// Parse JSON into dynamic object, convenient!
dynamic results = JObject.Parse(mapping);
List<DocumentType> deserializedObject = JsonConvert.DeserializeObject<List<DocumentType>>(mapping);
}
Exception
{"Cannot deserialize the current JSON object (e.g. {\"name\":\"value\"}) into type 'System.Collections.Generic.List`1[DocumentType]' because the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly.\r\nTo fix this error either change the JSON to a JSON array (e.g. [1,2,3]) or change the deserialized type so that it is a normal .NET type (e.g. not a primitive type like integer, not a collection type like an array or List) that can be deserialized from a JSON object. JsonObjectAttribute can also be added to the type to force it to deserialize from a JSON object.\r\nPath 'mappings', line 2, position 14."}
The desire result is to obtain the name of Cert and Exp_date fields
EDIT
public class DocumentType
{
public string Id { set { DocumentID = value; } get { return DocumentID; } }
public string DocumentID { set; get; }
public DateTime Created { set; get; }
.
.
.
public Dictionary<string, object> Metadata { set; get; }
}
The problem here is that your data structure does not match the JSON:
There are no arrays in the JSON. So there is no way you will be able to deserialize that into a C# List.
The "DocumentType" class doesn't match the JSON at all. The class has properties Created, CustomerID, and Deleted which are things like DateTime and string. But the JSON doesn't have those as DateTime or string. They are objects with subproperties named "type" and "format." The property "Metadata" isn't a dictionary: it is an object with a single property named "properties" which should probably be a dictionary.
The case doesn't match.
Don't do that weird thing with Id and DocumentId. The class should match the JSON exactly and literally. No business logic hidden in properties.
The root object has a property called "mappings" so you will need to drill-down before you get to the documents.
Once you successfully get the document, you will need to drill down to the property named "properties" to get to the fields you are interested in.
I suspect there could be multiple documents, and that the "mappings" property contains a list of those documents, where the property names are dynamic and correspond to the name of the document. It is entirely plausible to handle that but not using a deserialization + List approach.
I see 3 approaches here:
Fix the JSON. Not sure if this is possible in your case. If so, start by making mappings hold an array instead of having each document be a property named by the document name.
Fix the deserialization code to match the JSON document. json2csharp did an excellent job so start with that. It just doesn't know that "mappings" is really a Dictionary, not just a thing with a property named "basedoc12_kja."
Don't deserialize it at all. Just query for the metadata. take a look at http://www.newtonsoft.com/json/help/html/QueryingLINQtoJSON.htm which shows several ways to query JSON using JObject properties and LINQ.
Option 1
Example of a slightly cleaned-up JSON if you go that route:
{
"mappings": [
{
"name"" : "basedoc_12kja",
"properties": {
""created": "20150522",
etc.
},
Notice "mappings" is an array and the name became a property of the document. Now you can make a List<> or use JArray. Even better is to get rid of the unused stuff at the top, like this:
[
{
"name" : "basedoc_12kja",
"properties": {
"created"": "20150522",
etc.
},
]
Now it is just an array with no "mappings" at all.
** Option 2 **
Here is code that will do this via deserialization. There are two parts. Step one is to use what json2charp produced. I'll include that here for reference:
public class Created
{
public string type { get; set; }
public string format { get; set; }
}
public class CustomerID
{
public string type { get; set; }
}
public class Deleted
{
public string type { get; set; }
}
public class DocumentID
{
public string type { get; set; }
}
public class Id
{
public string type { get; set; }
}
public class Cert
{
public string type { get; set; }
}
public class ExpDate
{
public string format { get; set; }
}
public class Properties2
{
public Cert Cert { get; set; }
public ExpDate Exp_date { get; set; }
}
public class Metadata
{
public Properties2 properties { get; set; }
}
public class Properties
{
public Created created { get; set; }
public CustomerID customerID { get; set; }
public Deleted deleted { get; set; }
public DocumentID documentID { get; set; }
public Id id { get; set; }
public Metadata metadata { get; set; }
}
public class Basedoc12kja
{
public Properties properties { get; set; }
}
public class Mappings
{
public Basedoc12kja basedoc_12kja { get; set; }
}
public class RootObject
{
public Mappings mappings { get; set; }
}
Then, rename Basedoc12kja to DocumentType, and change RootObject to hold a dictionary. You get this:
public class DocumentType
{
public Properties properties { get; set; }
}
public class RootObject
{
public Dictionary<string, DocumentType> mappings { get; set; }
}
And if you want to get to properties other than just Cert and Exp_date then change Metadata to this:
public class Metadata
{
public Dictionary<string,object> properties { get; set; }
}
Now that can deserialize your document:
JObject results = JObject.Parse(mapping);
RootObject ro = results.ToObject<RootObject>()
You can enumerate through the mappings and get to the properties. They are still messy because of the JSON structure, but you can at least get there.
I hope this helps!
What you have here is a hierarchical dictionary of named properties, where each property can have a type, a format, and possibly a nested dictionary of named child properties -- metadata in your case. You can represent this with the following data model:
[DataContract]
public class PropertyData
{
[DataMember(Name="type", EmitDefaultValue=false)]
public string Type { get; set; }
[DataMember(Name = "format", EmitDefaultValue = false)]
public string Format { get; set; }
[DataMember(Name = "properties", EmitDefaultValue = false)]
public Dictionary<string, PropertyData> Properties { get; set; }
}
[DataContract]
public class Mappings
{
[DataMember(Name = "mappings", EmitDefaultValue = false)]
public Dictionary<string, PropertyData> DocumentMappings { get; set; }
}
(This data model doesn't capture the fact that a given property (probably) can only be a simple type or a complex type with nested properties - but not both. It would seem to suffice for your needs however.)
Then, given the JSON above, you would read it in and convert it to a dictionary of document name to metadata property name as follows:
var mappings = JsonConvert.DeserializeObject<Mappings>(json);
Debug.WriteLine(JsonConvert.SerializeObject(mappings, Formatting.Indented)); // Verify that all was read in.
var metadataNames = mappings.DocumentMappings.ToDictionary(doc => doc.Key, doc => doc.Value.Properties["metadata"].Properties.Select(p => p.Key).ToList());
Debug.WriteLine(JsonConvert.SerializeObject(metadataNames, Formatting.Indented)); // Inspect the resulting mapping table.
And the result is the dictionary of metadata names you want:
{
"basedoc_12kja": [
"Cert",
"Exp_date"
]
}
If you are concerned that the nested metadata might be missing sometimes and so generate NullReferenceExceptions in the query above, you can add null checks as follows:
// Extension methods to query or walk through nested properties, avoiding null reference exceptions when properties are missing
public static class PropertyDataExtensions
{
public static IEnumerable<KeyValuePair<string, PropertyData>> GetProperties(this PropertyData data)
{
if (data == null || data.Properties == null)
return Enumerable.Empty<KeyValuePair<string, PropertyData>>();
return data.Properties;
}
public static PropertyData GetProperty(this PropertyData data, string name)
{
if (data == null || data.Properties == null)
return null;
PropertyData child;
if (!data.Properties.TryGetValue(name, out child))
return null;
return child;
}
}
And then:
var metadataNamesSafe = mappings.DocumentMappings.ToDictionary(doc => doc.Key, doc => doc.Value.GetProperty("metadata").GetProperties().Select(p => p.Key).ToList());

Deserializing nested JSON arrays using RestSharp

I'm trying to deserialize the following JSON response using RestSharp. I have tried various model structures to extract the data to no avail. I keep getting tripped up on the nested arrays.
I do not have control over the service, so I can't change the format.
JSON Format:
[
{
"results": 19,
"statuscode": 200,
},
[
{
"id": 24,
"name": "bob"
},
{
"id": 82,
"name": "alice"
}
]
]
Using this model, I've been able to pull the data from the first object, but that's all. I'm not sure how exactly to read through the array that comes after the object.
public class Info
{
public int results { get; set; }
public int statuscode { get; set; }
}
Example deseralization:
var deserializer = new JsonDeserializer();
var wat = deserializer.Deserialize<List<List<Info>>>(response);
Am I just completely missing something here or are my only options to write a custom deserializer and/or use something like JSON.NET?
The problem is that your JSON array is exceptionally polymorphic: its first element is an object, and its second element is an array of objects. A more natural way to represent this would have been as a JSON object with two named properties -- but that's not what you have been given. Deserializing this directly to a c# POCO with two named properties in a single step with any serializer is going to be tricky since the JSON data model is quite different than your desired data model. Instead, it may be easiest to deserialize to an intermediate representation and convert. Luckily RestSharp has appropriate intermediate classes JsonObject and JsonArray.
Thus, if you want to deserialize to the following classes:
public class Info
{
public int results { get; set; }
public int statuscode { get; set; }
}
public class IdAndName
{
public int id { get; set; }
public string name { get; set; }
}
public class ResponseContent
{
public Info Info { get; set; }
public List<IdAndName> Data { get; set; }
}
You can do:
var array = (JsonArray)SimpleJson.DeserializeObject(response.Content);
var responseContent = (array == null ? (ResponseContent)null : new ResponseContent()
{
Info = array.OfType<JsonObject>().Select(o => SimpleJson.DeserializeObject<Info>(o.ToString())).FirstOrDefault(),
Data = array.OfType<JsonArray>().SelectMany(a => SimpleJson.DeserializeObject<List<IdAndName>>(a.ToString())).ToList()
});

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