[RESOLVED] JSON parse/token issue

[jj103]

I have a basic understanding of JSON, but clearly not enough.

I am able to create a messagebox with "ID" from this JSON

{
    "profileIconId": 0000,
    "name": "name",
    "id": 12345678,
}

with the following vb.net code

            Dim json As JObject = JObject.Parse(returnData)
            MsgBox(json.SelectToken("id"))

That's the easy part.

---

I am unable to display "tier" because there are two tokens by the name "tier". Here's the JSON (stripped down for easier reading)

[
    {
        "queueType": "RANKED_FLEX_SR",
        "rank": "III",
        "tier": "BRONZE",
        "leaguePoints": 5
    },
    {
        "queueType": "RANKED_SOLO_5x5",
        "rank": "III",
        "tier": "SILVER",
        "leaguePoints": 22
    }
]

I've tried the following in multiple different fasions to no avail.

            Dim json As JObject = JObject.Parse(returnData)
            MsgBox(json.SelectToken(1).SelectToken("tier"))

---

I wanted to learn how APIs worked so I went with a game I was familiar with, LoL. I've got the webrequests down (EASY MONEY) now I'm teaching myself what I can do with the information.

[Sitten Spynne]

I'm assuming you're using Newtonsoft JSON? It's nice to name the library you're using.

Most people don't use JObject.Parse() directly, it's a little clunkier than the kind of serialization JSON was designed for. I don't think you're using your query properly, though. For example:

json.SelectToken(1)

SelectToken() is:

Function SelectToken(path As String) As JToken

'path' is a "JPath expression" according to documentation, which I think meant to say "JSONPath". JSONPath is very much like XPath, but uses an object notiation. "1" is not valid JPath, this isn't an array.

I think to get what you want your code would look more like:

json.SelectToken("$[1].tier")

I'm not 100% sure there. It's "bad form" in JSON to return a raw array like that. Most developers would rather:

{ "queues" : [
        {
            ...
        },
        {
            ...
        }
    ]
}

That would let you grab the 2nd tier like:

json.SelectToken("$.queues[1].tier")

But this is not how I would parse this JSON. Instead, I would make an object to represent this JSON. It is "an array of something", where "something" has the four properties in the object. So:

Public Module Example

    Public Sub Main()

        Dim json = (get the string for your JSON)

        Dim items() As ExampleData = JsonConvert.DeserializeObject(Of ExampleData())(json)

        Console.WriteLine(items(1).Tier)

    End Sub

End Module

Public Class ExampleData
    Public Property QueueType As String
    Public Property Rank As String
    Public Property Tier As String
    Public Property LeaguePoints As String
End Class

That will probably do the trick, and messing with objects is much easier than messing with JObject and the other parser infrastructure.

[PlausiblyDamp]

Firstly I couldn't get the code you were using to work with the sample json, I needed to use JArray.Parse rather than JObject.Parse. However once it did that it was a matter of treating the variable json as an array, not as a json object.

So

Dim json = JArray.Parse(returnData)
Dim res = json(1).SelectToken("tier")

did the trick. I am not sure if this is likely to help as it depends on just how much you simplified the example data in question.

Personally I tend to avoid using the low level JObject etc. methods and create a class that defines the data structure I am working with and then have it deserialise straight into the object.

https://www.newtonsoft.com/json/help...lizeObject.htm has a quick example of how it would work, you would just need to define the class structure although something like https://jsonutils.com/ might be able to do that for you.

Edit : Too slow on the typing, beaten to it again!

[jj103]

Worked great! Thank you for the time and effort!

[jj103]

sorry about the library, slipped my mind. thank you for all the good read! learned a lot.

[jj103]

    Private Sub GetRank2()

        Try
            Dim Request As WebRequest = WebRequest.Create("https://na1.api.riotgames.com/lol/league/v3/positions/by-summoner/" & SummonerID & "?api_key=" & APIKey)
            Request.Credentials = CredentialCache.DefaultCredentials
            Request.Proxy = Nothing
            Dim Response As WebResponse = Request.GetResponse()
            Dim ResponseStream As System.IO.Stream = Response.GetResponseStream
            Dim StreamReader As New System.IO.StreamReader(ResponseStream)
            Dim returnData As String = StreamReader.ReadToEnd
            StreamReader.Close()

            Dim json = returnData
            Dim items() As GivePropClass = JsonConvert.DeserializeObject(Of GivePropClass())(json)

        Catch ex As Exception


        End Try

    End Sub

I have the class seperatly as GivePropClass. It's having an issue with "jsonconvert" (as italicized above)

[Sitten Spynne]

Try two things.

• Take a deep breath, facepalm, and put "Imports Newtonsoft.Json" at the top of your file. (A lot of times if you right-click, choose "Quick fixes" or whatever, it will suggest this.)
• Describe "having an issue", because I can't see your computer screen. You'll probably have to post the implementation of "GivePropClass" too.

[jj103]

Holy moly..did you feel the facepalm? I had Newtonsoft.Json.Linq, it never occured to me I'd need to import the rest.

I guess the following isn't correct? (This is my first time using Classes)

Public Class GivePropClass
    Public Property QueueType As String
    Public Property Rank As String
    Public Property Tier As String
    Public Property LeaguePoints As String
End Class

Private Sub GetRank2()

        Try
            Dim Request As WebRequest = WebRequest.Create("https://na1.api.riotgames.com/lol/league/v3/positions/by-summoner/" & SummonerID & "?api_key=" & APIKey)
            Request.Credentials = CredentialCache.DefaultCredentials
            Request.Proxy = Nothing
            Dim Response As WebResponse = Request.GetResponse()
            Dim ResponseStream As System.IO.Stream = Response.GetResponseStream
            Dim StreamReader As New System.IO.StreamReader(ResponseStream)
            Dim returnData As String = StreamReader.ReadToEnd
            StreamReader.Close()

            Dim json = returnData
            Dim items() As GivePropClass = JsonConvert.DeserializeObject(Of GivePropClass())(json)

            MsgBox(PositionData.Tier.ToString)


        Catch ex As Exception

            MsgBox("ERROR")

        End Try

    End Sub

I have Dim PositionData As GivePropClass in my main class.

Thank you for your patience!