Trying to integrate an HTTP GET request in my MS-Access database program - vba

Question

I want to import data from Anedot, a credit card processing firm, using a HTTP GET request from an MS Access program. Anedot uses a RESTful API and has provided help on there website: https://anedot.com/api/v2
I want to do this with VBA, and associate the import with a button on an MS Access form. I've read that this only possible with XML. Do I create the XML file with VBA?
I'd greatly appreciate some background information on how to get this done, as most of it is flying over my head. I don't really know where to begin and I'm having trouble finding anything useful on google.
So far I've realized I'll need to reference their API via a URL link (which they provide), and that I'll have to authorize my account using my username and a token ID. But how can I do this in VBA?
Thanks.

Answer 1

First of all try to make a request to API using basic authorization. Take a look at the below code as the example:
Sub Test()
' API URL from https://anedot.com/api/v2
sUrl = "https://api.anedot.com/v2/accounts"
' The username is the registered email address of your Anedot account
sUsername = "mymail#example.com"
' The password is your API token
sPassword = "1e56752e8531647d09ec8ab20c311ba928e54788"
sAuth = TextBase64Encode(sUsername & ":" & sPassword, "us-ascii") ' bXltYWlsQGV4YW1wbGUuY29tOjFlNTY3NTJlODUzMTY0N2QwOWVjOGFiMjBjMzExYmE5MjhlNTQ3ODg=
' Make the request
With CreateObject("MSXML2.XMLHTTP")
.Open "GET", sUrl, False
.SetRequestHeader "Authorization", "Basic " & sAuth
.Send
Debug.Print .ResponseText
Debug.Print .GetAllResponseHeaders
End With
End Sub
Function TextBase64Encode(sText, sCharset) ' 05 10 2016
Dim aBinary
With CreateObject("ADODB.Stream")
.Type = 2 ' adTypeText
.Open
.Charset = sCharset ' "us-ascii" for bytes to unicode
.WriteText sText
.Position = 0
.Type = 1 ' adTypeBinary
aBinary = .Read
.Close
End With
With CreateObject("Microsoft.XMLDOM").CreateElement("objNode")
.DataType = "bin.base64"
.NodeTypedValue = aBinary
TextBase64Encode = Replace(Replace(.Text, vbCr, ""), vbLf, "")
End With
End Function
Put your credentials to sUsername and sPassword variables, choose the appropriate URL from API help page and put it to sURL. Then you can parse JSON response from the server (currently you will see the response for /v2/accounts request in Immediate window).

Answer 2

It's a fairly lengthy question to be honest, but lets start with some code to get you going.
This Class Module ("clsXMLHttpMonitor") should help:
Option Explicit
Dim XMLHttpReq As MSXML2.ServerXMLHTTP
Dim RequestedVar As String
Dim P As Object
Public Sub Initialize(ByVal uXMLHttpRequest As Object, Optional RequestedValue As String = "")
RequestedVar = RequestedValue
Set XMLHttpReq = uXMLHttpRequest
End Sub
Sub ReadyStateChangeHandler()
If XMLHttpReq.ReadyState = 4 Then
If XMLHttpReq.Status = 200 Then
'Process the response here
Debug.Print "200 recieved"
Set P = JSON.parse(XMLHttpReq.responseText)
Else
If XMLHttpReq.Status = 404 Then
'Handle it
End If
End If
End If
End Sub
Function returnResponseHeaders() As String
returnResponseHeaders = XMLHttpReq.getAllResponseHeaders
XMLHttpReq.Send
End Function
Function returnFullText() As String
If XMLHttpReq.ReadyState = 4 Then
If XMLHttpReq.Status = 200 Then
returnFullText = XMLHttpReq.responseText
Else
returnFullText = "-1"
End If
Else
returnFullText = ""
End If
End Function
End Function
Use it like this:
Set XMLHttpReq = New MSXML2.ServerXMLHTTP
Set XMLHttpMon = New clsXMLHttpMonitor
XMLHttpMon.Initialize XMLHttpReq
XMLHttpReq.OnReadyStateChange = XMLHttpMon
XMLHttpReq.Open "POST", URL, True
XMLHttpReq.Send strPayload

Answer 3

As you seem to request a Json response from a URL, you can study the Json modules here for a full implementation that collects the Json response in a collection, which you then can use in your code or save to a table. See the demo module for examples:
VBA.CVRAPI