get data from a JSON string with VBA Excel

Question

I would like to get data from a JSON-String, which is in a JSON-Array, with VBA to display the data into an Excel-Worksheet. I'm using the library (VBA-JSON v2.3.1 JsonConverter)

I have the following JSON-Object

{

"deviceMessages":[
    {
        "messageSource":"cc",
        "externalSourceId":123,
        "messageId":"blabla",
        "internalDeviceId":66,
        "externalDeviceId":"123456789",
        "messageType":"UPLINK",
        "rawMessage":"{\"hello\":\"58\",\"hello\":\"hello\",\"name\":\"Peter\",\"ID\":\"12346789\",\"rxInfo\":[{\"GT_ID\":\"123456\",\"name2\":\"20202022022020\",\"time\":\"2021-02-12T03:51:43.050959Z\",\"rss\":12,\"SN\":8,\"location\":{\"latitude\":\"XX.XX\",\"longitude\":\"X.XXXXX\",\"altitude\":\"XXX\"}}],\"Info\":{\"frequency\":XXXXXXX,\"dr\":X},\"adr\":XXX,\"nt\":XXXX,\"port\":X,\"data\":\"XXXXXXXXXXXXXX\"}",
        "frame":"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX",
        "createdAt":"2021-02-12T03:51:43.050Z",
        "Json":"{\"temperature\":22.6,\"humidity\":37,\"light\":1,\"motion\":1,\"co2\":640,\"vdd\":3.647}",
        "rs":12,
        "framePort":16,
        "nr":8.0,
        "dataRate":5,
        "counter":123456,
        "GT":[
            {
                "id":1324,
                "externalId":"123456789",
                "SourceId":1234,
                "companyId":66,
                "sn":"xxxxxx",
                "name":"hello",
                "latitude":"xxxxxxxx",
                "longitude":"xxxxxxx",
                "range":null,
                "status":"OK",
                "Note":null,
                "lastSeen":"2021-02-12T04:04:39Z"
            }
        ]
    }
]

 }

I got the data with a VBA-code. That is working.

My code looks like this:

            Dim response2 As String
            Dim json1 As Object
            Dim ws2 As Worksheet
            strUrl = "https://xxxxxxxxxxxx/devices/11/"
            Set hReq = CreateObject("MSXML2.XMLHTTP")

        With hReq
                Set ws2 = Worksheets(3)
                .Open "GET", strUrl, False
                .SetRequestHeader "Authorization", "Bearer " & apitoken
                .Send
                response2 = hReq.responseText
                Set json1 = JsonConverter.ParseJson(response2)
                k = 2
                    For Each item In json1("deviceMessages")
                    ws2.Cells(k, 1) = item("createdAt")
                    ws2.Cells(k, 2) = item("dataFrame")
                    ws2.Cells(k, 3) = item("externalDeviceId")
                    ws2.Cells(k, 4) = item("externalSourceId")
                    ws2.Cells(k, 5) = item("internalDeviceId")
                    ws2.Cells(k, 6) = item("messageId")
                    ws2.Cells(k, 7) = item("messageType")
                    ws2.Cells(k, 8) = item("rawJson")
                    ws2.Cells(k, 9) = item("rawMessage")
                    k = k + 1
                    Next item
         End With

How can I get the data from "Json":"

{\"temperature\":22.6,\"humidity\":37,\"light\":1,\"motion\":1,\"co2\":640,\"vdd\":3.647} ?

For now, I get the information in a cell with the following format.

{"temperature":22.6,"humidity":37,"light":1,"motion":1,"co2":640,"vdd":3.647}

I would like to split the data into rows and columns like this:

I just don't know how to split the information from this JSON-String. I was searching for a solution, but I didn't find anything, that could work with my code.

Thanks for helping me!

Answer 1

The item you are returning is, itself, a json string. So to parse it out, in VBA, you need to create another json object.

eg:

For Each Item In JSON("deviceMessages")
    Set JSON2 = parsejson(Item("Json"))
        Debug.Print "Temperature", JSON2("temperature")
        Debug.Print "Humidity", JSON2("humidity")
        'etc
Next Item

And just to show the output:

Set JSON = parsejson(response2)

For Each Item In JSON("deviceMessages")
    Set JSON2 = parsejson(Item("Json"))
    For Each key In JSON2
        Debug.Print key, JSON2(key)
    Next key
Next Item

=>

temperature    22.6 
humidity       37 
light          1 
motion         1 
co2            640 
vdd            3.647 

Of course, you could also just use Power Query (available in Excel 2010+)

Here is M-code that outputs that data. All can be executed from the User Interface.

The original file is opened and parsed as a json.

Then filter on the result for the internal JSON; split that and output as a table.

Examine the Applied Steps window to see what happens at each stage of the code.

let
    Source = Json.Document(File.Contents("C:\Users\ron\Desktop\text3.json")),
    deviceMessages = Source[deviceMessages],
    deviceMessages1 = deviceMessages{0},
    #"Converted to Table" = Record.ToTable(deviceMessages1),
    #"Filtered Rows" = Table.SelectRows(#"Converted to Table", each ([Name] = "Json")),
    #"Added Custom" = Table.AddColumn(#"Filtered Rows", "Custom", each Json.Document([Value])),
    Custom = #"Added Custom"{0}[Custom],
    #"Converted to Table1" = Record.ToTable(Custom),
    #"Transposed Table" = Table.Transpose(#"Converted to Table1"),
    #"Promoted Headers" = Table.PromoteHeaders(#"Transposed Table", [PromoteAllScalars=true]),
    #"Changed Type" = Table.TransformColumnTypes(#"Promoted Headers",{{"temperature", type number}, {"humidity", Int64.Type}, {"light", Int64.Type}, {"motion", Int64.Type}, {"co2", Int64.Type}, {"vdd", type number}})
in
    #"Changed Type"