Handle JSON Object in XMLHttp response in Excel VBA Code

Question

I need to handle a JSON Object which is the response of XMLHTTPRequest in Excel VBA. I wrote the code below, but it doesn't work:

  Dim sc As Object
  Set sc = CreateObject("ScriptControl")
  sc.Language = "JScript"

  Dim strURL As String: strURL = "blah blah"

  Dim strRequest
  Dim XMLhttp: Set XMLhttp = CreateObject("msxml2.xmlhttp")
  Dim response As String

  XMLhttp.Open "POST", strURL, False
  XMLhttp.setrequestheader "Content-Type", "application/x-www-form-urlencoded"
  XMLhttp.send strRequest
  response = XMLhttp.responseText
  sc.Eval ("JSON.parse('" + response + "')")

I am getting the error Run-time error '429' ActiveX component can't create object in the line Set sc = CreateObject("ScriptControl")

Once we parsed the JSON Object, how do you access the values of the JSON Object?

P.S. My JSON Object sample: {"Success":true,"Message":"Blah blah"}

Solution 1

The code gets the data from nseindia site which comes as a JSON string in responseDiv element.

Required References

3 Class Module i have used

• cJSONScript
• cStringBuilder
• JSON

(I have picked these class modules from here)

You may download the file from this link

Standard Module

Const URl As String = "http://www.nseindia.com/live_market/dynaContent/live_watch/get_quote/GetQuote.jsp?symbol=ICICIBANK"
Sub xmlHttp()

    Dim xmlHttp As Object
    Set xmlHttp = CreateObject("MSXML2.ServerXMLHTTP.6.0")
    xmlHttp.Open "GET", URl & "&rnd=" & WorksheetFunction.RandBetween(1, 99), False
    xmlHttp.setRequestHeader "Content-Type", "text/xml"
    xmlHttp.send

    Dim html As MSHTML.HTMLDocument
    Set html = New MSHTML.HTMLDocument
    html.body.innerHTML = xmlHttp.ResponseText

    Dim divData As Object
    Set divData = html.getElementById("responseDiv")
    '?divData.innerHTML
    ' Here you will get a string which is a JSON data

    Dim strDiv As String, startVal As Long, endVal As Long
    strDiv = divData.innerHTML
    startVal = InStr(1, strDiv, "data", vbTextCompare)
    endVal = InStr(startVal, strDiv, "]", vbTextCompare)
    strDiv = "{" & Mid(strDiv, startVal - 1, (endVal - startVal) + 2) & "}"


    Dim JSON As New JSON

    Dim p As Object
    Set p = JSON.parse(strDiv)

    i = 1
    For Each item In p("data")(1)
       Cells(i, 1) = item
       Cells(i, 2) = p("data")(1)(item)
        i = i + 1
    Next

 End Sub

Solution 2

I've had a lot of success with the following library:

https://github.com/VBA-tools/VBA-JSON

The library uses Scripting.Dictionary for Objects and Collection for Arrays and I haven't had any issues with parsing pretty complex json files.

As for more info on parsing json yourself, check out this question for some background on issues surrounding the JScriptTypeInfo object returned from the sc.Eval call:

Excel VBA: Parsed JSON Object Loop

Finally, for some helpful classes for working with XMLHTTPRequest, a little plug for my project, VBA-Web:

https://github.com/VBA-tools/VBA-Web

Solution 3

I know this is an old question but I've created a simple way to interact with Json from web requests. Where i've wrapped the web request as well.

Available here

You need the following code as a class module called Json

Public Enum ResponseFormat
    Text
    Json
End Enum
Private pResponseText As String
Private pResponseJson
Private pScriptControl As Object
'Request method returns the responsetext and optionally will fill out json or xml objects
Public Function request(url As String, Optional postParameters As String = "", Optional format As ResponseFormat = ResponseFormat.Json) As String
    Dim xml
    Dim requestType As String
    If postParameters <> "" Then
        requestType = "POST"
    Else
        requestType = "GET"
    End If

    Set xml = CreateObject("MSXML2.XMLHTTP")
    xml.Open requestType, url, False
    xml.setRequestHeader "Content-Type", "application/json"
    xml.setRequestHeader "Accept", "application/json"
    If postParameters <> "" Then
        xml.send (postParameters)
    Else
        xml.send
    End If
    pResponseText = xml.ResponseText
    request = pResponseText
    Select Case format
        Case Json
            SetJson
    End Select
End Function
Private Sub SetJson()
    Dim qt As String
    qt = """"
    Set pScriptControl = CreateObject("scriptcontrol")
    pScriptControl.Language = "JScript"
    pScriptControl.eval "var obj=(" & pResponseText & ")"
    'pScriptControl.ExecuteStatement "var rootObj = null"
    pScriptControl.AddCode "function getObject(){return obj;}"
    'pScriptControl.eval "var rootObj=obj[" & qt & "query" & qt & "]"
    pScriptControl.AddCode "function getRootObject(){return rootObj;}"
    pScriptControl.AddCode "function getCount(){ return rootObj.length;}"
    pScriptControl.AddCode "function getBaseValue(){return baseValue;}"
    pScriptControl.AddCode "function getValue(){ return arrayValue;}"
    Set pResponseJson = pScriptControl.Run("getObject")
End Sub
Public Function setJsonRoot(rootPath As String)
    If rootPath = "" Then
        pScriptControl.ExecuteStatement "rootObj = obj"
    Else
        pScriptControl.ExecuteStatement "rootObj = obj." & rootPath
    End If
    Set setJsonRoot = pScriptControl.Run("getRootObject")
End Function
Public Function getJsonObjectCount()
    getJsonObjectCount = pScriptControl.Run("getCount")
End Function
Public Function getJsonObjectValue(path As String)
    pScriptControl.ExecuteStatement "baseValue = obj." & path
    getJsonObjectValue = pScriptControl.Run("getBaseValue")
End Function
Public Function getJsonArrayValue(index, key As String)
    Dim qt As String
    qt = """"
    If InStr(key, ".") > 0 Then
        arr = Split(key, ".")
        key = ""
        For Each cKey In arr
            key = key + "[" & qt & cKey & qt & "]"
        Next
    Else
        key = "[" & qt & key & qt & "]"
    End If
    Dim statement As String
    statement = "arrayValue = rootObj[" & index & "]" & key

    pScriptControl.ExecuteStatement statement
    getJsonArrayValue = pScriptControl.Run("getValue", index, key)
End Function
Public Property Get ResponseText() As String
    ResponseText = pResponseText
End Property
Public Property Get ResponseJson()
    ResponseJson = pResponseJson
End Property
Public Property Get ScriptControl() As Object
    ScriptControl = pScriptControl
End Property

Example Usage (from ThisWorkbook):

Sub Example()
    Dim j
    'clear current range
    Range("A2:A1000").ClearContents
    'create ajax object
    Set j = New Json
    'make yql request for json
    j.request "https://query.yahooapis.com/v1/public/yql?q=show%20tables&format=json&callback=&diagnostics=true"
    'Debug.Print j.ResponseText
    'set root of data
    Set obj = j.setJsonRoot("query.results.table")
    Dim index
    'determine the total number of records returned
    index = j.getJsonObjectCount
    'if you need a field value from the object that is not in the array
    'tempValue = j.getJsonObjectValue("query.created")
    Dim x As Long
    x = 2
    If index > 0 Then
        For i = 0 To index - 1
            'set cell to the value of content field
            Range("A" & x).value = j.getJsonArrayValue(i, "content")
            x = x + 1
        Next
    Else
        MsgBox "No items found."
    End If
End Sub