MongoDB BsonDocument - Serialize JSON as key-object - c#

I have a doubt if it is possible to serialize a collection of BsonDocument results as a JSON pair of key objects.
For example, I attach a piece of code that creates a collection of BsonDocument with and _id and name as fields,
using MongoDB.Bson;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ExampleBsonDocumentSerializeToJsonAsArray
{
class Program
{
static void Main(string[] args)
{
BsonDocument[] data = new BsonDocument[]{
new BsonDocument {
{ "_id" , "1" },
{ "name" , "name_1" },
{ "description" , "description_1" },
}
,new BsonDocument {
{ "_id" , "2" },
{ "name" , "name_2" },
{ "description" , "description_2" },
}
,new BsonDocument {
{ "_id" , "3" },
{ "name" , "name_3" },
{ "description" , "description_3" },
}
};
Console.WriteLine(data.ToJson());
}
}
}
List 1.1
The piece from the list 1.1 shows it gives output as a JSON array of objects:
[{
"_id": "1",
"name": "name_1",
"description": "description_1"
}, {
"_id": "2",
"name": "name_2",
"description": "description_2"
}, {
"_id": "3",
"name": "name_3",
"description": "description_3"
}]
Having the field '_id' as the key of the collection, I would like to serialize it as a set of key-object JSON instead of an array of objects. The result of serialized JSON should be like this,
{
"1": {
"name": "name_1"
, "description": "description_1"
},
"2": {
"name": "name_2"
, "description": "description_2"
},
"3": {
"name": "name_3"
, "description": "description_3"
}
}
I don't know whether is this possible or not.

You can convert BsonDocument to Dictionary via System.Linq.
using System.Linq;
var kvp = data.AsEnumerable()
.ToDictionary(x => x["_id"], x => new { name = x["name"], description = x["description"] });
Console.WriteLine(kvp.ToJson());
Sample program

Related

How to deserialize a json array with multiple data types?

I now need to deserialize a JSON that looks like this:
{
"arguments": {
"game": [
"--username",
"--version",
"--assetsDir",
{
"rules": [
{
"action": "allow",
"features": {
"is_demo_user": true
}
}
],
"value": "--demo"
},
{
"rules": [
{
"action": "allow",
"features": {
"has_custom_resolution": true
}
}
],
"value": [
"--width",
"--height"
]
}
]
}
}
As you can see, the array named "game" has both "value" and "object" in it. (But the fact is WORSE than this example, the number of elements is NOT certain)
And the data type of arguments.game[*].value is NOT certain, too.
I used to use classes to describe it, but deserialization failed.
Can't seem to describe an array with multiple element types with a class?
I am using Json.NET. Is there any way to deserialize this "game" array.
Thanks.
Is it a requirement to deserialize to an instance of a class? You could use an ExpandoObject:
using System.Dynamic;
using Newtonsoft.Json;
using Newtonsoft.Json.Converters;
Console.WriteLine("Hello, World!");
string json = #"{
""arguments"": {
""game"": [
""--username"",
""--version"",
""--assetsDir"",
{
""rules"": [
{
""action"": ""allow"",
""features"": {
""is_demo_user"": true
}
}
],
""value"": ""--demo""
},
{
""rules"": [
{
""action"": ""allow"",
""features"": {
""has_custom_resolution"": true
}
}
],
""value"": [
""--width"",
""--height""
]
}
]
}
}";
var expConverter = new ExpandoObjectConverter();
dynamic obj = JsonConvert.DeserializeObject<ExpandoObject>(json, expConverter);
The obj variable will contain the result of the JSON conversion, then you can traverse the dynamic object in code.
For example, to get a list of strings under 'game':
IList<object> list = new List<object>(obj.arguments.game);
foreach (object str in list)
{
if (str as string != null)
{
Console.WriteLine(str as string);
}
}

NEST How to find field on subdocument

I've a sample company JSON document structure like this:
[
{
"id": "id1",
"name": "company1",
"employees": [
{
"name": "employee1",
"education": "education1"
},
{
"name": "employee2",
"education": "education2"
}
]
}
]
and I'm doing queries like this:
GET companies/_search
{
"query": {
"bool": {
"must": [
{
"term": {
"employees.education": {
"value": "education1"
}
}
},
{
"term": {
"employees.education": {
"value": "education2"
}
}
}
]
}
}
}
The query is build using NEST:
var filters = new List<Func<QueryContainerDescriptor<Company>, QueryContainer>>();
foreach (var education in educationsToFilter)
{
filters.Add(fq => fq.Term(f => f.Employees.Suffix("education"), education));
}
var searchResponse = _client.Search<Company>(s => s
.Query(q => q
.Bool(bq => bq
.Filter(filters)
)
)
);
Is there a better way of finding the Term Field instead of using the Suffix-method? I would like a more type safe way.
You can resolve nested field name with this lambda expression:
fq.Term(f => f.Employees.FirstOrDefault().Education, education)
Hope that helps.

How to write the value of one json property in one line?

It is necessary to write value of "Coordinates" property in json without hyphenation for the following lines, not using ToString() (without converting the value to a string). The desired result is shown below.
{
"Id": null,
"Style": "1234",
"Geometry": {
"Type": "Polygon",
"Coordinates": [[[47541.470259278358,6846.8710054924586],[47540.359922950891,6845.4552435801925],[47541.470259278358,6846.8710054924586]]],
"Properties": [
{
"PointType": "Straight"
},
{
"PointType": "Straight"
},
{
"PointType": "Straight"
}
]
}
}
but not:
{
"Id": null,
"Style": "1234",
"Geometry": {
"Type": "Polygon",
"Coordinates": "[[[47541.470259278358,6846.8710054924586],[47540.359922950891,6845.4552435801925],[47541.470259278358,6846.8710054924586]]]",
"Properties": [
{
"PointType": "Straight"
},
{
"PointType": "Straight"
},
{
"PointType": "Straight"
}
]
}
}
A function that serializes the corresponding class object in json:
JToken ToJson()
{
using (var writer = new JTokenWriter()) {
JsonSerializer serializer = new JsonSerializer();
serializer.Serialize(writer, this);
return writer.Token;
}
}
it seems your second case contains Coordinates property as serialized string.
why should not use
var string = JsonConvert.SerializeObject(YourObject) ?
But you should install https://www.nuget.org/packages/Newtonsoft.Json/ first
You could use string type for properties where you need double quotes and use array or number if you don't need it

Change specific property

How do I change the CourseName from History to Gym if the ID is equally to 2?
{
"Result": {
"StudentInfo": {
"ID": 20,
"Name": "Bob",
"IgnoreThis": [
{
"ID": 123,
"Something":"abc"
}
]
},
"Courses": [
{
"ID": 1,
"CourseName":"Math"
},
{
"ID": 2,
"CourseName":"History"
}
]
}
}
This code below is just a fantasy code to show what I had in mind:
{ "Result":{ "Course" : [ if id=2 inside "Courses" then "CourseName":"Gym" ] }}
I will be using Postman.
Here is a solution that works (it could possibly be tidied up); it does however use Newtonsoft.Json (a well-known nuget package).
using System.Linq;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
string blah = "{'Result': { 'StudentInfo': { 'ID': 20, 'Name': 'Bob', 'IgnoreThis': [{'ID': 123,'Something':'abc'}]}, 'Courses': [{'ID': 1,'CourseName':'Math'},{'ID': 2,'CourseName':'History'}]}}";
dynamic json = JsonConvert.DeserializeObject(blah);
var dynamicJson = json.Result.Courses; // included to show how dynamic could be accessed instead
JObject arr = json;
foreach (var course in arr["Result"]["Courses"].Where(x => x["ID"].Value<int>() == 2))
{
course["CourseName"] = "Gym";
}
var newResult = json.ToString();
}
}
}

Search for a nested value inside of a JSON.net object in C#

I've got a JSON stream coming back from a server, and I need to search for a specific value of the node "ID" using JSON.net to parse the data.
And I can almost make it work, but not quite because the results coming back are deeply nested in each other -- this is due to the fact that I'm getting a folder structure back. I've boiled the JSON down to a much simpler version. I'm getting this:
{
"data": {
"id": 0,
"name": "",
"childFolders": [{
"id": 19002,
"name": "Locker",
"childFolders": [{
"id": 19003,
"name": "Folder1",
"childFolders": [],
"childComponents": [{
"id": 19005,
"name": "route1",
"state": "STOPPED",
"type": "ROUTE"
}]
}, {
"id": 19004,
"name": "Folder2",
"childFolders": [],
"childComponents": [{
"id": 19008,
"name": "comm1",
"state": "STOPPED",
"type": "COMMUNICATION_POINT"
}, {
"id": 19006,
"name": "route2",
"state": "STOPPED",
"type": "ROUTE"
}, {
"id": 19007,
"name": "route3",
"state": "STOPPED",
"type": "ROUTE"
}]
}],
"childComponents": []
}],
"childComponents": []
},
"error": null
}
I can almost get there by going:
var objects = JObject.Parse(results);
var subobjects = objects["data"]["childFolders"][0]["childFolders"][1];
I can see in the debug view that it'll parse the object, but won't let me search within.
My ultimate goal is to be able to search for "route3" and get back 19007, since that's the ID for that route. I've found some results, but all of them assume you know how far nested the object is. The object I'm searching for could be 2 deep or 20 deep.
My ultimate goal is to be able to search for "route3" and get back 19007
You can use linq and Descendants method of JObject to do it:
var dirs = JObject.Parse(json)
.Descendants()
.Where(x=>x is JObject)
.Where(x=>x["id"]!=null && x["name"]!=null)
.Select(x =>new { ID= (int)x["id"], Name = (string)x["name"] })
.ToList();
var id = dirs.Find(x => x.Name == "route3").ID;
You can use the SelectToken or SelectTokens functions to provide a JPath to search for your desired node. Here is an example that would provide you the route based on name:
JObject.Parse(jsonData)["data"].SelectToken("$..childComponents[?(#.name=='route3')]")
You can find more documentation on JPath here
Simply write a recursive function:
private Thing FindThing(Thing thing, string name)
{
if (thing.name == name)
return thing;
foreach (var subThing in thing.childFolders.Concat(thing.childComponents))
{
var foundSub = FindThing(subThing, name);
if (foundSub != null)
return foundSub;
}
return null;
}
class RootObject
{
public Thing data { get; set; }
}
class Thing
{
public int id { get; set; }
public string name { get; set; }
public List<Thing> childFolders { get; set; } = new List<Thing>();
public List<Thing> childComponents { get; set; } = new List<Thing>();
}
And using it:
var obj = JsonConvert.DeserializeObject<RootObject>(jsonString);
var result = FindThing(obj.data, "route3");

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