Incorrectly parsing double header caused by Proxy

[Tycho-S]

I just started using VBA-Web in a corporate environment. I noticed I was getting JSON parse errors (11000) on the HTTP header.

It turned out that this is because our proxy also provides its own header. Here's the beginning of the content:

HTTP/1.1 200 Connection Established
Proxy-Agent: Zscaler/6.0

HTTP/1.1 200 OK
Content-Length: 584929
Content-Type: application/json; charset=utf-8
X-RateLimit-Limit: 100000
X-RateLimit-Remaining: 99998
X-RateLimit-Reset: 1516764010
X-Powered-By: ASP.NET
Date: Tue, 23 Jan 2018 16:39:09 GMT

....<JSON CODE>...

The problem was that VBA-Web attempted to parse JSON after the first empty line, not the second.

I added a function that checks if the text after the first empty line starts with "HTTP", if so it removed everything up to that :). I just wanted to let you know that this can happen sometimes. It seems to work right now, not getting parse errors anymore.

I can submit my function if you like but I'm not sure if my solution is the way you'd want to deal with this, it's more like a quick fix.

[Tycho-S]

Just to cover this here, this is what I've done to make it work. To be honest I don't know how to submit a pull request 😞 I'm not really a developer. But I should lean git some time 😄

I changed this line in webClient.Execute from:

web_Response.CreateFromCurl Me, Request, web_Result.Output

To:

web_Response.CreateFromCurl Me, Request, WebHelpers.CleanOutput(web_Result.Output)

And I added this function in WebHelpers:

 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ '
''
' CleanOutput
' Removes Proxy Server output before actual HTTP output from server, to fix parsing error
'
' @param {String} Output
' @param[out] {String} CleanOutput
''

Public Function CleanOutput(Original As String) As String

' Find the first empty line

Dim PosEmptyLine As Integer

CleanOutput = Original ' Set the output in case we don't start changing it

PosEmptyLine = InStr(1, Original, Chr(13) & Chr(10) & Chr(13) & Chr(10))
If (PosEmptyLine > 0) Then
    ' First empty line found
    If (StrComp(Mid(Original, PosEmptyLine + 4, 4), "http", vbTextCompare) = 0) Then
        ' Line right after First empty line starts with HTTP. Remove everything before that
        CleanOutput = Mid(Original, PosEmptyLine + 4)
    End If

End If

End Function

Just so you could incorporate this if you wish.

[timhall]

Thanks for raising the issue and for the fix @TychoSchenkeveld, I'll merge it soon.