(PureBasic) Manually Follow HTTP Redirects

Demonstrates how to manually follow redirects for an HTTP GET.

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkHttpResponse.pb"
IncludeFile "CkHttp.pb"

Procedure ChilkatExample()

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

    http.i = CkHttp::ckCreate()
    If http.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    ; 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:
    CkHttp::setCkFollowRedirects(http, 0)

    resp.i = CkHttp::ckQuickGetObj(http,"http://yandex.ru/")
    If CkHttp::ckLastMethodSuccess(http) = 0
        Debug CkHttp::ckLastErrorText(http)
        CkHttp::ckDispose(http)
        ProcedureReturn
    EndIf

    status.i = CkHttpResponse::ckStatusCode(resp)
    Debug "HTTP Response Status: " + Str(status)

    ; The FinalRedirectUrl property will contain the redirect URL
    ; If FollowRedirects was equal to 1, then all of the 
    ; intermediate redirects (if any) would be followed until
    ; there were no more redirects.  However, because 
    ; FollowRedirects is not 1, FinalRedirectUrl contains
    ; the next redirect URL.

    loopCount.i = 0

    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 "Redirect URL: " + CkHttp::ckFinalRedirectUrl(http)

        CkHttpResponse::ckDispose(resp)

        nextUrl.s = CkHttp::ckFinalRedirectUrl(http)
        resp = CkHttp::ckQuickGetObj(http,nextUrl)
        If CkHttp::ckLastMethodSuccess(http) = 0
            Debug CkHttp::ckLastErrorText(http)
            CkHttp::ckDispose(http)
            ProcedureReturn
        EndIf

        status = CkHttpResponse::ckStatusCode(resp)
        Debug "HTTP Response Status: " + Str(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
            CkHttpResponse::ckDispose(resp)

            Debug "Too many redirects."
            CkHttp::ckDispose(http)
            ProcedureReturn
        EndIf

        CkHttpResponse::ckDispose(resp)

    Wend


    CkHttp::ckDispose(http)


    ProcedureReturn
EndProcedure