Tracing HTTP Redirects

Example to trace through HTTP redirects.

Download Chilkat HTTP ActiveX

CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @sTmp0 nvarchar(4000)
    DECLARE @http int
    EXEC @hr = sp_OACreate 'Chilkat.Http', @http OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    DECLARE @success int

    --  Any string unlocks the component for the 1st 30-days.
    EXEC sp_OAMethod @http, 'UnlockComponent', @success OUT, 'Anything for 30-day trial'
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @http, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        RETURN
      END

    DECLARE @url nvarchar(4000)

    DECLARE @html nvarchar(4000)

    DECLARE @status int

    SELECT @url = 'http://www.planyourweddingonline.co.za/'

    --  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:
    EXEC sp_OASetProperty @http, 'FollowRedirects', 0

    --  Send the HTTP GET and return the content in a string.
    EXEC sp_OAMethod @http, 'QuickGetStr', @html OUT, @url
    IF @html Is NULL 
      BEGIN
        EXEC sp_OAGetProperty @http, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
      END

    EXEC sp_OAGetProperty @http, 'LastStatus', @status OUT



    PRINT '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.

    EXEC sp_OAGetProperty @http, 'FinalRedirectUrl', @sTmp0 OUT

    PRINT 'Redirect URL: ' + @sTmp0

    DECLARE @loopCount int

    SELECT @loopCount = 0

    WHILE (@status = 302)
      BEGIN
        EXEC sp_OAGetProperty @http, 'FinalRedirectUrl', @url OUT

        EXEC sp_OAMethod @http, 'QuickGetStr', @html OUT, @url
        IF @html Is NULL 
          BEGIN
            EXEC sp_OAGetProperty @http, 'LastErrorText', @sTmp0 OUT
            PRINT @sTmp0
            BREAK
          END
        EXEC sp_OAGetProperty @http, 'LastStatus', @status OUT


        EXEC sp_OAGetProperty @http, 'FinalRedirectUrl', @sTmp0 OUT

        PRINT 'Redirect URL: ' + @sTmp0

        --  You may wish to check that if FinalRedirectUrl
        --  equals the URL just retrieved.  If so, then break out of the
        --  loop.  (This check is omitted in this example.)

        --  Instead, this example will prevent infinite loops by
        --  keeping a loopCount and only allows following a max
        --  of 10 redirects:
        SELECT @loopCount = @loopCount + 1
        IF @loopCount > 10
          BEGIN
            BREAK
          END

      END
END
GO