Reputation: 1203
I need convert data from excel table with about twenty columns and a lot of rows into json. I don't found a short example of code for this purpose in vba. I found this one https://github.com/VBA-tools/VBA-JSON/blob/master/JsonConverter.bas , but it is very large. May be it is a shorter example?
Upvotes: 4
Views: 26522
Reputation: 8260
So I would pass in the range to a JavaScript function and let it iterate over the Excel object model and build the array in JavaScript. Then call a JavaScript library to convert array into a string (hat tip Douglas Crockford) and simply return the string to VBA. So no string operations in VBA.
The JavaScript function is given below but depends upon Douglas Crockford's library at https://raw.githubusercontent.com/douglascrockford/JSON-js/master/json2.js. Save this in a file and then amend VBA code with the correct file path so the JavaScript is loaded into the Microsoft Script Control.
function ExcelTableToJSON(rngTable) {
try {
if (rngTable && rngTable['Rows'] && rngTable['Columns']) {
var rowCount = rngTable.Rows.Count;
var columnCount = rngTable.Columns.Count;
var arr = new Array();
for (rowLoop = 1; rowLoop <= rowCount; rowLoop++) {
arr[rowLoop - 1] = new Array();
for (columnLoop = 1; columnLoop <= columnCount; columnLoop++) {
var rngCell = rngTable.Cells(rowLoop, columnLoop);
var cellValue = rngCell.Value2;
arr[rowLoop - 1][columnLoop - 1] = cellValue;
}
}
return JSON.stringify(arr);
}
else {
return { error: '#Either rngTable is null or does not support Rows or Columns property!' };
}
}
catch(err) {
return {error: err.message};
}
}
The Excel VBA code is thus
Option Explicit
'In response to
'http://stackoverflow.com/questions/38100193/is-it-possible-in-vba-convert-excel-table-to-json?rq=1
'Is it possible in VBA convert Excel table to json
'Tools->References->
'Microsoft Script Control 1.0; {0E59F1D2-1FBE-11D0-8FF2-00A0D10038BC}; C:\Windows\SysWOW64\msscript.ocx
Private Sub Test()
Dim oScriptEngine As ScriptControl
Set oScriptEngine = New ScriptControl
oScriptEngine.Language = "JScript"
oScriptEngine.AddCode GetJavaScriptLibraryFromWeb("https://raw.githubusercontent.com/douglascrockford/JSON-js/master/json2.js")
Dim sJavascriptCode As String
sJavascriptCode = CreateObject("Scripting.FileSystemObject").GetFile("<<<Your file path to javascript file>>>\ExcelTableToJSON.js").OpenAsTextStream.ReadAll
oScriptEngine.AddCode sJavascriptCode
Dim rngTable As Excel.Range
Set rngTable = ThisWorkbook.Worksheets.Item("Sheet2").Range("A1:B2")
rngTable.Cells(1, 1) = 1.2
rngTable.Cells(1, 2) = "red"
rngTable.Cells(2, 1) = True
rngTable.Cells(2, 2) = "=2+2"
Dim sStringified As String
sStringified = oScriptEngine.Run("ExcelTableToJSON", rngTable)
Debug.Assert sStringified = "[[1.2,""red""],[true,4]]"
Stop
End Sub
Public Function GetJavaScriptLibraryFromWeb(ByVal sURL As String) As String
Dim xHTTPRequest As Object 'MSXML2.XMLHTTP60
Set xHTTPRequest = VBA.CreateObject("MSXML2.XMLHTTP.6.0")
xHTTPRequest.Open "GET", sURL, False
xHTTPRequest.send
GetJavaScriptLibraryFromWeb = xHTTPRequest.responseText
End Function
Upvotes: 7
Reputation: 393
I'd go with modified version of this one: http://www.excelvbamacros.in/2015/01/export-range-in-jason-format.html
if you want to write it to file there's a code:
Dim fso As Object
Set fso = CreateObject("Scripting.FileSystemObject")
Dim Fileout As Object
Set Fileout = fso.CreateTextFile("C:\some_dir\mydata.json", True, True)
Fileout.Write jsonStringFromConvertFunction
Fileout.Close
Upvotes: 7