WebResponse.cls

VERSION 1.0 CLASS
BEGIN
  MultiUse = -1  'True
END
Attribute VB_Name = "WebResponse"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = True
''
' WebResponse v4.1.2
' (c) Tim Hall - https://github.com/VBA-tools/VBA-Web
'
' Wrapper for http/cURL responses that includes parsed Data based on WebRequest.ResponseFormat.
'
' Usage:
' ```VB.net
' Dim Response As WebResponse
' Set Response = Client.Execute(Request)
'
' If Response.StatusCode = WebStatusCode.Ok Then
'   ' Response.Headers, Response.Cookies
'   ' Response.Data -> Parsed Response.Content based on Request.ResponseFormat
'   ' Response.Body -> Raw response bytes
' Else
'   Debug.Print "Error: " & Response.StatusCode & " - " & Response.Content
' End If
' ```
'
' Errors:
' 11030 / 80042b16 / -2147210474 - Error creating from http
' 11031 / 80042b17 / -2147210473 - Error creating from cURL
' 11032 / 80042b18 / -2147210472 - Error extracting headers
'
' @class WebResponse
' @author tim.hall.engr@gmail.com
' @license MIT (http://www.opensource.org/licenses/mit-license.php)
'' ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ '
Option Explicit

Private web_CrLf As String

' --------------------------------------------- '
' Properties
' --------------------------------------------- '

''
' Status code that the server returned (e.g. 200).
'
' @property StatusCode
' @type WebStatusCode
''
Public StatusCode As WebStatusCode

''
' Status string that the server returned (e.g. `404 -> "Not Found"`)
'
' @property StatusDescription
' @type String
''
Public StatusDescription As String

''
' Content string that the server returned.
'
' @property Content
' @type String
''
Public Content As String

''
' Raw bytes for the response.
'
' @property Body
' @type Byte()
''
Public Body As Variant

''
' Parsed `Content` or `Body` based on the `WebRequest.ResponseFormat`.
'
' @property Data
' @type Dictionary|Collection
''
Public Data As Object

''
' Headers that were included with the response.
' (`Collection` of `KeyValue`)
'
' @property Headers
' @type Collection
''
Public Headers As Collection

''
' Cookies that were included with the response.
' (`Collection` of `KeyValue`)
'
' @property Cookies
' @type Collection
''
Public Cookies As Collection

' ============================================= '
' Public Methods
' ============================================= '

''
' Helper for updating the response with the given updated response values.
' Useful for `ByRef` cases to update response in place.
'
' @method Update
' @param Updated {WebResponse} Updated `WebResponse` to pull updated values from
''
Public Sub Update(Updated As WebResponse)
    Me.StatusCode = Updated.StatusCode
    Me.StatusDescription = Updated.StatusDescription
    Me.Content = Updated.Content
    Me.Body = Updated.Body
    Set Me.Headers = Updated.Headers
    Set Me.Cookies = Updated.Cookies
    Set Me.Data = Updated.Data
End Sub

''
' Create response from http
'
' @internal
' @method CreateFromHttp
' @param {WebClient} Client
' @param {WebRequest} Request
' @param {WinHttpRequest} Http
' @throws 11030 / 80042b16 / -2147210474 - Error creating from http
''
Public Sub CreateFromHttp(Client As WebClient, Request As WebRequest, Http As Object)
    On Error GoTo web_ErrorHandling

    Me.StatusCode = Http.Status
    Me.StatusDescription = Http.StatusText
    Me.Content = Http.ResponseText
    Me.Body = Http.ResponseBody

    web_LoadValues Http.GetAllResponseHeaders, Me.Content, Me.Body, Request

    Exit Sub

web_ErrorHandling:

    Dim web_ErrorDescription As String
    web_ErrorDescription = "An error occurred while creating response from http" & vbNewLine & _
        Err.Number & VBA.IIf(Err.Number < 0, " (" & VBA.LCase$(VBA.Hex$(Err.Number)) & ")", "") & ": " & Err.Description

    WebHelpers.LogError web_ErrorDescription, "WebResponse.CreateFromHttp", 11030 + vbObjectError
    Err.Raise 11030 + vbObjectError, "WebResponse.CreateFromHttp", web_ErrorDescription
End Sub

''
' Create response from cURL
'
' @internal
' @method CreateFromCurl
' @param {WebClient} Client
' @param {WebRequest} Request
' @param {String} Result
' @throws 11031 / 80042b17 / -2147210473 - Error creating from cURL
''
Public Sub CreateFromCurl(Client As WebClient, Request As WebRequest, Result As String)
    On Error GoTo web_ErrorHandling

    Dim web_Lines() As String

    web_Lines = VBA.Split(Result, web_CrLf)

    Me.StatusCode = web_ExtractStatusFromCurlResponse(web_Lines)
    Me.StatusDescription = web_ExtractStatusTextFromCurlResponse(web_Lines)
    Me.Content = web_ExtractResponseTextFromCurlResponse(web_Lines)
    Me.Body = WebHelpers.StringToAnsiBytes(Me.Content)

    web_LoadValues web_ExtractHeadersFromCurlResponse(web_Lines), Me.Content, Me.Body, Request

    Exit Sub

web_ErrorHandling:

    Dim web_ErrorDescription As String
    web_ErrorDescription = "An error occurred while creating response from cURL" & vbNewLine & _
        Err.Number & VBA.IIf(Err.Number < 0, " (" & VBA.LCase$(VBA.Hex$(Err.Number)) & ")", "") & ": " & Err.Description

    WebHelpers.LogError web_ErrorDescription, "WebResponse.CreateFromCurl", 11031 + vbObjectError
    Err.Raise 11031 + vbObjectError, "WebResponse.CreateFromCurl", web_ErrorDescription
End Sub

''
' Extract headers from response headers
'
' @internal
' @method ExtractHeaders
' @param {String} ResponseHeaders
' @return {Collection} Headers
' @throws 11032 / 80042b18 / -2147210472 - Error extracting headers
''
Public Function ExtractHeaders(ResponseHeaders As String) As Collection
    On Error GoTo web_ErrorHandling

    Dim web_Lines As Variant
    Dim web_i As Integer
    Dim web_Headers As New Collection
    Dim web_Header As Dictionary
    Dim web_ColonPosition As Long
    Dim web_Multiline As Boolean

    web_Lines = VBA.Split(ResponseHeaders, web_CrLf)

    For web_i = LBound(web_Lines) To (UBound(web_Lines) + 1)
        If web_i > UBound(web_Lines) Then
            web_Headers.Add web_Header
        ElseIf web_Lines(web_i) <> "" Then
            web_ColonPosition = VBA.InStr(1, web_Lines(web_i), ":")
            If web_ColonPosition = 0 And Not web_Header Is Nothing Then
                ' Assume part of multi-line header
                web_Multiline = True
            ElseIf web_Multiline Then
                ' Close out multi-line string
                web_Multiline = False
                web_Headers.Add web_Header
            ElseIf Not web_Header Is Nothing Then
                ' Add previous header
                web_Headers.Add web_Header
            End If

            If Not web_Multiline Then
                Set web_Header = WebHelpers.CreateKeyValue( _
                    Key:=VBA.Trim(VBA.Mid$(web_Lines(web_i), 1, web_ColonPosition - 1)), _
                    Value:=VBA.Trim(VBA.Mid$(web_Lines(web_i), web_ColonPosition + 1, VBA.Len(web_Lines(web_i)))) _
                )
            Else
                web_Header("Value") = web_Header("Value") & web_CrLf & web_Lines(web_i)
            End If
        End If
    Next web_i

    Set ExtractHeaders = web_Headers
    Exit Function

web_ErrorHandling:

    Dim web_ErrorDescription As String
    web_ErrorDescription = "An error occurred while extracting headers" & vbNewLine & _
        Err.Number & VBA.IIf(Err.Number < 0, " (" & VBA.LCase$(VBA.Hex$(Err.Number)) & ")", "") & ": " & Err.Description

    WebHelpers.LogError web_ErrorDescription, "WebResponse.CreateFromCurl", 11032 + vbObjectError
    Err.Raise 11032 + vbObjectError, "WebResponse.CreateFromCurl", web_ErrorDescription
End Function

''
' Extract cookies from response headers
'
' @internal
' @method ExtractCookies
' @param {Collection} Headers
' @return {Collection} Cookies
''
Public Function ExtractCookies(Headers As Collection) As Collection
    Dim web_Header As Dictionary
    Dim web_Cookie As String
    Dim web_Key As String
    Dim web_Value As String
    Dim web_Cookies As New Collection

    For Each web_Header In Headers
        If web_Header("Key") = "Set-Cookie" Then
            web_Cookie = web_Header("Value")
            If VBA.InStr(1, web_Cookie, "=") > 0 Then
                web_Key = VBA.Mid$(web_Cookie, 1, VBA.InStr(1, web_Cookie, "=") - 1)
                web_Value = VBA.Mid$(web_Cookie, VBA.InStr(1, web_Cookie, "=") + 1, VBA.Len(web_Cookie))

                ' Ignore text after semi-colon
                If VBA.InStr(1, web_Value, ";") > 0 Then
                    web_Value = VBA.Mid$(web_Value, 1, VBA.InStr(1, web_Value, ";") - 1)
                End If

                ' Ignore surrounding quotes
                If VBA.Left$(web_Value, 1) = """" Then
                    web_Value = VBA.Mid$(web_Value, 2, VBA.Len(web_Value) - 2)
                End If

                web_Cookies.Add WebHelpers.CreateKeyValue(web_Key, WebHelpers.UrlDecode(web_Value, PlusAsSpace:=False, EncodingMode:=UrlEncodingMode.CookieUrlEncoding))
            Else
                WebHelpers.LogWarning _
                    "Unrecognized cookie format: " & web_Cookie, "WebResponse.ExtractCookies"
            End If
        End If
    Next web_Header

    Set ExtractCookies = web_Cookies
End Function

' ============================================= '
' Private Functions
' ============================================= '

Private Sub web_LoadValues(web_Headers As String, web_Content As String, web_Body As Variant, web_Request As WebRequest)
    ' Convert content to data by format
    If web_Request.ResponseFormat <> WebFormat.PlainText Then
        On Error Resume Next
        Set Me.Data = _
            WebHelpers.ParseByFormat(web_Content, web_Request.ResponseFormat, web_Request.CustomResponseFormat, web_Body)

        If Err.Number <> 0 Then
            WebHelpers.LogError Err.Description, Err.Source, Err.Number
            Err.Clear
        End If
        On Error GoTo 0
    End If

    ' Extract headers
    Set Me.Headers = ExtractHeaders(web_Headers)

    ' Extract cookies
    Set Me.Cookies = ExtractCookies(Me.Headers)
End Sub

Private Function web_ExtractStatusFromCurlResponse(web_CurlResponseLines() As String) As Long
    Dim web_StatusLineParts() As String

    web_StatusLineParts = VBA.Split(web_CurlResponseLines(web_FindStatusLine(web_CurlResponseLines)), " ")
    web_ExtractStatusFromCurlResponse = VBA.CLng(web_StatusLineParts(1))
End Function

Private Function web_ExtractStatusTextFromCurlResponse(web_CurlResponseLines() As String) As String
    Dim web_StatusLineParts() As String
    Dim web_i As Long
    Dim web_StatusText As String

    web_StatusLineParts = VBA.Split(web_CurlResponseLines(web_FindStatusLine(web_CurlResponseLines)), " ", 3)
    web_ExtractStatusTextFromCurlResponse = web_StatusLineParts(2)
End Function

Private Function web_ExtractHeadersFromCurlResponse(web_CurlResponseLines() As String) As String
    Dim web_StatusLineIndex As Long
    Dim web_BlankLineIndex As Long
    Dim web_HeaderLines() As String
    Dim web_WriteIndex As Long
    Dim web_ReadIndex As Long

    ' Find status line and blank line before body
    web_StatusLineIndex = web_FindStatusLine(web_CurlResponseLines)
    web_BlankLineIndex = web_FindBlankLine(web_CurlResponseLines)

    ' Extract headers string
    ReDim web_HeaderLines(0 To web_BlankLineIndex - 2 - web_StatusLineIndex)

    web_WriteIndex = 0
    For web_ReadIndex = (web_StatusLineIndex + 1) To web_BlankLineIndex - 1
        web_HeaderLines(web_WriteIndex) = web_CurlResponseLines(web_ReadIndex)
        web_WriteIndex = web_WriteIndex + 1
    Next web_ReadIndex

    web_ExtractHeadersFromCurlResponse = VBA.Join$(web_HeaderLines, web_CrLf)
End Function

Private Function web_ExtractResponseTextFromCurlResponse(web_CurlResponseLines() As String) As String
    Dim web_BlankLineIndex As Long
    Dim web_BodyLines() As String
    Dim web_WriteIndex As Long
    Dim web_ReadIndex As Long

    ' Find blank line before body
    web_BlankLineIndex = web_FindBlankLine(web_CurlResponseLines)

    ' Extract body string
    ReDim web_BodyLines(0 To UBound(web_CurlResponseLines) - web_BlankLineIndex - 1)

    web_WriteIndex = 0
    For web_ReadIndex = web_BlankLineIndex + 1 To UBound(web_CurlResponseLines)
        web_BodyLines(web_WriteIndex) = web_CurlResponseLines(web_ReadIndex)
        web_WriteIndex = web_WriteIndex + 1
    Next web_ReadIndex

    web_ExtractResponseTextFromCurlResponse = VBA.Join$(web_BodyLines, web_CrLf)
End Function

Private Function web_FindStatusLine(web_CurlResponseLines() As String) As Long
    ' Special case for cURL: 100 Continue is included before final status code
    ' -> ignore 100 and find final status code (next non-100 status code)
    For web_FindStatusLine = LBound(web_CurlResponseLines) To UBound(web_CurlResponseLines)
        If VBA.Trim$(web_CurlResponseLines(web_FindStatusLine)) <> "" Then
            If VBA.Split(web_CurlResponseLines(web_FindStatusLine), " ")(1) <> "100" Then
                Exit Function
            End If
        End If
    Next web_FindStatusLine
End Function

Private Function web_FindBlankLine(web_CurlResponseLines() As String) As Long
    For web_FindBlankLine = (web_FindStatusLine(web_CurlResponseLines) + 1) To UBound(web_CurlResponseLines)
        If VBA.Trim$(web_CurlResponseLines(web_FindBlankLine)) = "" Then
            Exit Function
        End If
    Next web_FindBlankLine
End Function

Private Sub Class_Initialize()
    web_CrLf = VBA.Chr$(13) & VBA.Chr$(10)

    Set Headers = New Collection
    Set Cookies = New Collection
End Sub