How can I URL encode a string in Excel VBA?

Question

Is there a built-in way to URL encode a string in Excel VBA or do I need to hand roll this functionality?

Answer 1

Version of the above supporting UTF8:

Private Const CP_UTF8 = 65001

#If VBA7 Then
  Private Declare PtrSafe Function WideCharToMultiByte Lib "kernel32" ( _
    ByVal CodePage As Long, _
    ByVal dwFlags As Long, _
    ByVal lpWideCharStr As LongPtr, _
    ByVal cchWideChar As Long, _
    ByVal lpMultiByteStr As LongPtr, _
    ByVal cbMultiByte As Long, _
    ByVal lpDefaultChar As Long, _
    ByVal lpUsedDefaultChar As Long _
    ) As Long
#Else
  Private Declare Function WideCharToMultiByte Lib "kernel32" ( _
    ByVal CodePage As Long, _
    ByVal dwFlags As Long, _
    ByVal lpWideCharStr As Long, _
    ByVal cchWideChar As Long, _
    ByVal lpMultiByteStr As Long, _
    ByVal cbMultiByte As Long, _
    ByVal lpDefaultChar As Long, _
    ByVal lpUsedDefaultChar As Long _
    ) As Long
#End If

Public Function UTF16To8(ByVal UTF16 As String) As String
Dim sBuffer As String
Dim lLength As Long
If UTF16 <> "" Then
    #If VBA7 Then
        lLength = WideCharToMultiByte(CP_UTF8, 0, CLngPtr(StrPtr(UTF16)), -1, 0, 0, 0, 0)
    #Else
        lLength = WideCharToMultiByte(CP_UTF8, 0, StrPtr(UTF16), -1, 0, 0, 0, 0)
    #End If
    sBuffer = Space$(lLength)
    #If VBA7 Then
        lLength = WideCharToMultiByte(CP_UTF8, 0, CLngPtr(StrPtr(UTF16)), -1, CLngPtr(StrPtr(sBuffer)), LenB(sBuffer), 0, 0)
    #Else
        lLength = WideCharToMultiByte(CP_UTF8, 0, StrPtr(UTF16), -1, StrPtr(sBuffer), LenB(sBuffer), 0, 0)
    #End If
    sBuffer = StrConv(sBuffer, vbUnicode)
    UTF16To8 = Left$(sBuffer, lLength - 1)
Else
    UTF16To8 = ""
End If
End Function

Public Function URLEncode( _
   StringVal As String, _
   Optional SpaceAsPlus As Boolean = False, _
   Optional UTF8Encode As Boolean = True _
) As String

Dim StringValCopy As String: StringValCopy = IIf(UTF8Encode, UTF16To8(StringVal), StringVal)
Dim StringLen As Long: StringLen = Len(StringValCopy)

If StringLen > 0 Then
    ReDim Result(StringLen) As String
    Dim I As Long, CharCode As Integer
    Dim Char As String, Space As String

  If SpaceAsPlus Then Space = "+" Else Space = "%20"

  For I = 1 To StringLen
    Char = Mid$(StringValCopy, I, 1)
    CharCode = Asc(Char)
    Select Case CharCode
      Case 97 To 122, 65 To 90, 48 To 57, 45, 46, 95, 126
        Result(I) = Char
      Case 32
        Result(I) = Space
      Case 0 To 15
        Result(I) = "%0" & Hex(CharCode)
      Case Else
        Result(I) = "%" & Hex(CharCode)
    End Select
  Next I
  URLEncode = Join(Result, "")

End If
End Function

Enjoy!

Answer 2

One more solution via htmlfile ActiveX:

Function EncodeUriComponent(strText)
    Static objHtmlfile As Object
    If objHtmlfile Is Nothing Then
        Set objHtmlfile = CreateObject("htmlfile")
        objHtmlfile.parentWindow.execScript "function encode(s) {return encodeURIComponent(s)}", "jscript"
    End If
    EncodeUriComponent = objHtmlfile.parentWindow.encode(strText)
End Function

Declaring htmlfile DOM document object as static variable gives the only small delay when called first time due to init, and makes this function very fast for numerous calls, e. g. for me it converts the string of 100 chars length 100000 times in 2 seconds approx..

Answer 3

(Bump on an old thread). Just for kicks, here's a version that uses pointers to assemble the result string. It's about 2x - 4x as fast as the faster second version in the accepted answer.

Public Declare PtrSafe Sub Mem_Copy Lib "kernel32" _
    Alias "RtlMoveMemory" (ByRef Destination As Any, ByRef Source As Any, ByVal Length As Long)

Public Declare PtrSafe Sub Mem_Read2 Lib "msvbvm60" _
    Alias "GetMem2" (ByRef Source As Any, ByRef Destination As Any)

Public Function URLEncodePart(ByRef RawURL As String) As String

    Dim pChar As LongPtr, iChar As Integer, i As Long
    Dim strHex As String, pHex As LongPtr
    Dim strOut As String, pOut As LongPtr
    Dim pOutStart As LongPtr, pLo As LongPtr, pHi As LongPtr
    Dim lngLength As Long
    Dim cpyLength As Long
    Dim iStart As Long

    pChar = StrPtr(RawURL)
    If pChar = 0 Then Exit Function

    lngLength = Len(RawURL)
    strOut = Space(lngLength * 3)
    pOut = StrPtr(strOut)
    pOutStart = pOut
    strHex = "0123456789ABCDEF"
    pHex = StrPtr(strHex)

    iStart = 1
    For i = 1 To lngLength
        Mem_Read2 ByVal pChar, iChar
        Select Case iChar
            Case 97 To 122, 65 To 90, 48 To 57, 45, 46, 95, 126
              ' Ok
            Case Else
                If iStart < i Then
                    cpyLength = (i - iStart) * 2
                    Mem_Copy ByVal pOut, ByVal pChar - cpyLength, cpyLength
                    pOut = pOut + cpyLength
                End If

                pHi = pHex + ((iChar And &HF0) / 8)
                pLo = pHex + 2 * (iChar And &HF)

                Mem_Read2 37, ByVal pOut
                Mem_Read2 ByVal pHi, ByVal pOut + 2
                Mem_Read2 ByVal pLo, ByVal pOut + 4
                pOut = pOut + 6

                iStart = i + 1
        End Select
        pChar = pChar + 2
    Next

    If iStart <= lngLength Then
        cpyLength = (lngLength - iStart + 1) * 2
        Mem_Copy ByVal pOut, ByVal pChar - cpyLength, cpyLength
        pOut = pOut + cpyLength
    End If

    URLEncodePart = Left$(strOut, (pOut - pOutStart) / 2)

End Function

Answer 4

This snippet i have used in my application to encode the URL so may this can help you to do the same.

Function URLEncode(ByVal str As String) As String
        Dim intLen As Integer
        Dim x As Integer
        Dim curChar As Long
        Dim newStr As String
        intLen = Len(str)
        newStr = ""

        For x = 1 To intLen
            curChar = Asc(Mid$(str, x, 1))

            If (curChar < 48 Or curChar > 57) And _
                (curChar < 65 Or curChar > 90) And _
                (curChar < 97 Or curChar > 122) Then
                                newStr = newStr & "%" & Hex(curChar)
            Else
                newStr = newStr & Chr(curChar)
            End If
        Next x

        URLEncode = newStr
    End Function

Answer 5

The accepted answer's code stopped on a Unicode error in Access 2013, so I wrote a function for myself with high readability that should follow RFC 3986 according to Davis Peixoto, and cause minimal trouble in various environments.

Note: The percent sign itself must be replaced first, or it will double-encode any previously encoded characters. Replacing space with + was added, not to conform with RFC 3986, but to provide links that don't break due to formatting. It is optional.

Public Function URLEncode(str As Variant) As String
    Dim i As Integer, sChar() As String, sPerc() As String
    sChar = Split("%|!|*|'|(|)|;|:|@|&|=|+|$|,|/|?|#|[|]| ", "|")
    sPerc = Split("%25 %21 %2A %27 %28 %29 %3B %3A %40 %26 %3D %2B %24 %2C %2F %3F %23 %5B %5D +", " ")
    URLEncode = Nz(str)
    For i = 0 To 19
        URLEncode = Replace(URLEncode, sChar(i), sPerc(i))
    Next i
End Function

Answer 6

Although, this one is very old. I have come up with a solution based in this answer:

Dim ScriptEngine As ScriptControl
Set ScriptEngine = New ScriptControl
ScriptEngine.Language = "JScript"

ScriptEngine.AddCode "function encode(str) {return encodeURIComponent(str);}"
Dim encoded As String
encoded = ScriptEngine.Run("encode", "€ömE.sdfds")

Add Microsoft Script Control as reference and you are done.

Just a side note, because of the JS part, this is fully UTF-8-compatible. VB will convert correctly from UTF-16 to UTF-8.