Generating PDF from Base64 string in VBA - json

Question

I have the following JSON response:
{
"status": "Success",
"label": "pdf_base64_string",
"order": "ABC123456"
}
I'm trying to save a PDF file from the Base64 string per the following code:
FileData = Base64DecodeString(pdf_base64_string)
fileNum = FreeFile
FilePath = "C:\label.pdf"
Open FilePath For Binary Access Write As #fileNum
Put #fileNum, 1, FileData
Close #fileNum
This results in a broken/invalid PDF file (not recognized by the PDF viewer).

Answer 1

Adapted from: Inserting an Image into a sheet using Base64 in VBA?
This works for me - saves the file to the same location as the workbook running the code.
Sub TestDecodeToFile()
Dim strTempPath As String
Dim b64test As String
'little face logo
b64test = "R0lGODlhDwAPAKECAAAAzMzM/////wAAACwAAAAADwAPAAACIISPeQHsrZ5ModrLlN48" & _
"CXF8m2iQ3YmmKqVlRtW4MLwWACH+H09wdGltaXplZCBieSBVbGVhZCBTbWFydFNhdmVyIQAAOw=="
strTempPath = ThisWorkbook.Path & "\temp.png" 'use workbook path as temp path
'save byte array to temp file
Open strTempPath For Binary As #1
Put #1, 1, DecodeBase64(b64test)
Close #1
End Sub
Private Function DecodeBase64(ByVal strData As String) As Byte()
Dim objXML As Object 'MSXML2.DOMDocument
Dim objNode As Object 'MSXML2.IXMLDOMElement
'get dom document
Set objXML = CreateObject("MSXML2.DOMDocument")
'create node with type of base 64 and decode
Set objNode = objXML.createElement("b64")
objNode.DataType = "bin.base64"
objNode.Text = strData
DecodeBase64 = objNode.nodeTypedValue
'clean up
Set objNode = Nothing
Set objXML = Nothing
End Function

Answer 2

Points need to take care of for pdf to base64
If you are converting the pdf to base64/blob for rest API then do not use string variables because the size of a string variable is 32200 only.
If you are using pdf for rest API then you need to read the pdf in binary-only [ do not read it by text]
In VBA JSON file is sent through the text-only so try to use the streams instead of the JSON file.
I am sharing the code which does the binary conversion of base64 of the pdf file.
Function EncodeFileBase64(FileName As String) As String
fileNum = FreeFile
Open FileName For Binary As fileNum
ReDim arrData(LOF(fileNum) - 1)
Get fileNum, , arrData
Close fileNum
Set objXML = New MSXML2.DOMDocument
Set objNode = objXML.createElement("b64")
objNode.DataType = "bin.base64"
objNode.nodeTypedValue = arrData
EncodeFileBase64 = objNode.text
EncodeFileBase64 = Replace(objNode.text, vbLf, "")
Set objNode = Nothing
Set objXML = Nothing
End Function