(SQL Server) HTTP Redirect Handling

Examine HTTP redirects.

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

-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @iTmp0 int
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    -- This example assumes the Chilkat API to have been previously unlocked.
    -- See Global Unlock Sample for sample code.

    DECLARE @http int
    -- Use "Chilkat_9_5_0.Http" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Http', @http OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    DECLARE @url nvarchar(4000)

    DECLARE @html nvarchar(4000)

    DECLARE @status int

    -- Please note: The URL used in this example was a valid redirect many years ago,
    -- but the site does not exist any longer..
    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 automatically taken:
    EXEC sp_OASetProperty @http, 'FollowRedirects', 1

    -- Send the HTTP GET and return the content in a string.
    EXEC sp_OAMethod @http, 'QuickGetStr', @html OUT, @url
    EXEC sp_OAGetProperty @http, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 <> 1
      BEGIN
        EXEC sp_OAGetProperty @http, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
      END

    -- On success, LastErrorText will provide information about
    -- what happened during the call.

    PRINT '--------------- LastErrorText ------------------'
    EXEC sp_OAGetProperty @http, 'LastErrorText', @sTmp0 OUT
    PRINT @sTmp0

    PRINT '------------------------------------------------'

    -- In this case, we see something like this:
    -- ChilkatLog:
    --   QuickGetHtml:
    --     DllDate: Jul 27 2007
    --     url: http://www.planyourweddingonline.co.za/
    --     httpServer: www.planyourweddingonline.co.za
    --     port: 80
    --     StatusCode: 302
    --     StatusText: Found
    --     Reading chunked response
    --     redirectUrl: main/main/home/index.php
    --     url: http://www.planyourweddingonline.co.za/main/main/home/index.php
    --     StatusCode: 302
    --     StatusText: Found
    --     Reading chunked response
    --     redirectUrl: /main/main/home/index.php?SMC=1
    --     url: http://www.planyourweddingonline.co.za/main/main/home/index.php?SMC=1
    --     StatusCode: 200
    --     StatusText: OK
    --     CompressedSize: 7434
    --     UncompressedSize: 40999

    -- Was the GET redirected?
    EXEC sp_OAGetProperty @http, 'WasRedirected', @iTmp0 OUT
    IF @iTmp0 = 1
      BEGIN

        PRINT 'Chilkat HTTP followed the redirect.'

        -- Display the final redirect URL:

        PRINT 'Final URL:'
        EXEC sp_OAGetProperty @http, 'FinalRedirectUrl', @sTmp0 OUT
        PRINT @sTmp0

        -- Note the HTML returned is from the final redirect URL.

      END
    ELSE
      BEGIN

        PRINT 'Not redirected.'
      END

    EXEC sp_OAGetProperty @http, 'LastStatus', @status OUT
    IF @status = 200
      BEGIN

        PRINT 'status = 200, OK!'
      END
    ELSE
      BEGIN

        PRINT 'HTTP Response status = ' + @status

        -- Display the complete response header.
        EXEC sp_OAGetProperty @http, 'LastResponseHeader', @sTmp0 OUT
        PRINT @sTmp0
      END

    -- Now try it without following redirects:

    PRINT '-------- Now trying without following redirects....'
    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
    EXEC sp_OAGetProperty @http, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 <> 1
      BEGIN
        -- the HTML string can NULL if a 302 redirect response is received.

        PRINT 'HTML string returned NULL...'
      END

    -- On success, LastErrorText will provide information about
    -- what happened during the call.

    PRINT '--------------- LastErrorText ------------------'
    EXEC sp_OAGetProperty @http, 'LastErrorText', @sTmp0 OUT
    PRINT @sTmp0

    PRINT '------------------------------------------------'

    -- In this case, we see something like this:
    -- ChilkatLog:
    --   QuickGetHtml:
    --     DllDate: Jul 27 2007
    --     url: http://www.planyourweddingonline.co.za/
    --     StatusCode: 302
    --     StatusText: Found
    --     Reading chunked response
    --     redirectUrl: main/main/home/index.php

    -- Was this a redirect?  Even if FollowRedirects is false,
    -- WasRedirected will be true (non-zero) if the response
    -- indicated a redirect.
    EXEC sp_OAGetProperty @http, 'WasRedirected', @iTmp0 OUT
    IF @iTmp0 = 1
      BEGIN

        PRINT 'This was a redirect response'

        -- When redirects are not followed, FinalRedirectUrl
        -- contains the redirect URL that would've been taken...
        -- Display the redirect URL, which was not taken...

        PRINT 'Redirect URL:'
        EXEC sp_OAGetProperty @http, 'FinalRedirectUrl', @sTmp0 OUT
        PRINT @sTmp0

      END
    ELSE
      BEGIN

        PRINT 'Not redirected.'
      END

    EXEC sp_OAGetProperty @http, 'LastStatus', @status OUT
    IF @status = 200
      BEGIN

        PRINT 'status = 200, OK!'
      END
    ELSE
      BEGIN

        PRINT 'HTTP Response status = ' + @status

        -- Display the complete response header.
        EXEC sp_OAGetProperty @http, 'LastResponseHeader', @sTmp0 OUT
        PRINT @sTmp0
      END

    EXEC @hr = sp_OADestroy @http


END
GO