(Excel) Manually Follow HTTP Redirects

Demonstrates how to manually follow redirects for an HTTP GET.

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' This example requires the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

Dim http As Chilkat.Http
Set http = Chilkat.NewHttp

' The FollowRedirects property controls whether redirects
' are automatically followed.  The default behavior is to
' automatically follow redirects.

' Explicitly set FollowRedirects so that redirects are NOT automatically taken:
http.FollowRedirects = False


Set resp = http.QuickGetObj("http://yandex.ru/")
If (http.LastMethodSuccess = False) Then
    Debug.Print http.LastErrorText
    Exit Sub
End If


status = resp.StatusCode
Debug.Print "HTTP Response Status: "; status

' The FinalRedirectUrl property will contain the redirect URL
' If FollowRedirects was equal to True, then all of the 
' intermediate redirects (if any) would be followed until
' there were no more redirects.  However, because 
' FollowRedirects is not True, FinalRedirectUrl contains
' the next redirect URL.


loopCount = 0

Do While (status = 302)

    ' IMPORTANT: This example requires Chilkat v9.5.0.49 or greater because
    ' the FinalRedirectUrl in prior versions is only set when redirects
    ' are automatically followed.   Starting in v9.5.0.49, the FinalRedirectUrl is
    ' set to the next redirect URL when a 301/302 response is received, regardless
    ' of the value of the FollowRedirects property.
    Debug.Print "Redirect URL: "; http.FinalRedirectUrl


    nextUrl = http.FinalRedirectUrl
    Set resp = http.QuickGetObj(nextUrl)
    If (http.LastMethodSuccess = False) Then
        Debug.Print http.LastErrorText
        Exit Sub
    End If

    status = resp.StatusCode
    Debug.Print "HTTP Response Status: "; status

    ' For safety, prevent infinite loops by
    ' keeping a loopCount and only allows following a max 
    ' of 10 redirects:
    loopCount = loopCount + 1
    If (loopCount > 10) Then

        Debug.Print "Too many redirects."
        Exit Sub
    End If

Loop