Handle JSON Object in XMLHttp response in Excel VBA Code - json

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"}

Answer 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

Answer 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

Answer 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