(DataFlex) Manually Follow HTTP Redirects

Demonstrates how to manually follow redirects for an HTTP GET.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

Use ChilkatAx-win32.pkg

Procedure Test
    Handle hoHttp
    Variant vResp
    Handle hoResp
    Integer iStatus
    Integer iLoopCount
    String sNextUrl
    String sTemp1
    Boolean bTemp1

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

    Get Create (RefClass(cComChilkatHttp)) To hoHttp
    If (Not(IsComObjectCreated(hoHttp))) Begin
        Send CreateComObject of hoHttp
    End

    // 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:
    Set ComFollowRedirects Of hoHttp To False

    Get ComQuickGetObj Of hoHttp "http://yandex.ru/" To vResp
    If (IsComObject(vResp)) Begin
        Get Create (RefClass(cComChilkatHttpResponse)) To hoResp
        Set pvComObject Of hoResp To vResp
    End
    Get ComLastMethodSuccess Of hoHttp To bTemp1
    If (bTemp1 = False) Begin
        Get ComLastErrorText Of hoHttp To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get ComStatusCode Of hoResp To iStatus
    Showln "HTTP Response Status: " iStatus

    // 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.

    Move 0 To iLoopCount

    While (iStatus = 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.
        Get ComFinalRedirectUrl Of hoHttp To sTemp1
        Showln "Redirect URL: " sTemp1

        Send Destroy of hoResp

        Get ComFinalRedirectUrl Of hoHttp To sNextUrl
        Get ComQuickGetObj Of hoHttp sNextUrl To vResp
        If (IsComObject(vResp)) Begin
            Get Create (RefClass(cComChilkatHttpResponse)) To hoResp
            Set pvComObject Of hoResp To vResp
        End
        Get ComLastMethodSuccess Of hoHttp To bTemp1
        If (bTemp1 = False) Begin
            Get ComLastErrorText Of hoHttp To sTemp1
            Showln sTemp1
            Procedure_Return
        End

        Get ComStatusCode Of hoResp To iStatus
        Showln "HTTP Response Status: " iStatus

        // For safety, prevent infinite loops by
        // keeping a loopCount and only allows following a max 
        // of 10 redirects:
        Move (iLoopCount + 1) To iLoopCount
        If (iLoopCount > 10) Begin
            Send Destroy of hoResp
            Showln "Too many redirects."
            Procedure_Return
        End

        Send Destroy of hoResp

    Loop



End_Procedure