Re: Filtering and modification of Response in Tapestry

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Hi,
as you suggested, it is possible to capture output of handling request by
subclassing HttpServletResponseWrapper, providing your own
ServletOutputStream, and wrapping the original HttpServletResponse inside a
filter on the requested processing pipeline. This way is not specific to
Tapestry, maybe you only need to remember that Tapestry on the request
processing pipeline is implemented as a filter, not a servlet. Tapestry
itself uses this approach to implement compressing responses, see class
org.apache.tapestry5.internal.gzip.GZipFilter.  I don't know why it is not
working for you, probably you have a bug, but without seeing your code it
hard to help you.

Best regards,
Cezary




On Sat, Nov 30, 2019 at 10:38 AM Ric 2000 <[email protected]> wrote:

> Dear all,
>
> I'm struggling on how to filter and modify the response sent to the client
> in a Tapestry web application.
> I tried first with a RequestFilter contributed to the RequestHandler
> service.
> The problem occurred when I tried to read the content of the current
> response out stream. There are different hints on the internet how to do a
> "capture" of this output stream using a custom HttpServletResponseWrapper
> and overwriting the write method of the ServletOutputStream, to get the
> current content of the outputstream as byte array.
>
> But this is always empty, regardless of how I try to do it.
>
> Can you tell me, what is the right way in Tapestry to do it? Which service
> do I have to contribute, in which phase of the request processing the
> response is filled and can be read, BEFORE it is send to the client?
>
> Thanks a lot for your suggestions, I really appreciate them!
>
> Best Regards, Ric
>

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