BSP - How to set header-field "no-store"

Question

Hello.
I need to set the HTTP-header-field "no-store" in a BSP-application. The Problem is, that i do'nt know, how to do this.
I just do'nt know, which strings have to be passed to the method "set_header_field". The W3C-RFC gives the following information:
    Cache-Control   = "Cache-Control" ":" 1#cache-directive
    cache-directive = cache-request-directive
         | cache-response-directive
    cache-request-directive =
           "no-cache"                          ; Section 14.9.1
         | "no-store"                          ; Section 14.9.2
         | "max-age" "=" delta-seconds         ; Section 14.9.3, 14.9.4
         | "max-stale" [ "=" delta-seconds ]   ; Section 14.9.3
         | "min-fresh" "=" delta-seconds       ; Section 14.9.3
         | "no-transform"                      ; Section 14.9.5
         | "only-if-cached"                    ; Section 14.9.4
         | cache-extension                     ; Section 14.9.6
     cache-response-directive =
           "public"                               ; Section 14.9.1
         | "private" [ "=" <"> 1#field-name <"> ] ; Section 14.9.1
         | "no-cache" [ "=" <"> 1#field-name <"> ]; Section 14.9.1
         | "no-store"                             ; Section 14.9.2
         | "no-transform"                         ; Section 14.9.5
         | "must-revalidate"                      ; Section 14.9.4
         | "proxy-revalidate"                     ; Section 14.9.4
         | "max-age" "=" delta-seconds            ; Section 14.9.3
         | "s-maxage" "=" delta-seconds           ; Section 14.9.3
         | cache-extension                        ; Section 14.9.6
    cache-extension = token "=" ( token
I already tried some combinations, but none of them worked. As i have already searched the SDN-Forum and google, i hope that somebody in this forum knows, how to do the trick...
Regards
Jörg Neumann

Answer 1

Hello Cornelia.
I have tried setting the header field "max-age=0" and copied the set_header_field-instructions into the eventhandler OnInputProcessing, but this does not solve the problem - it made it even worse.
After setting the header-field "max-age=0", the browser read the page from the local cache for EVERY click on the back-button.
This seemed a little weird to me and so i started testing around...
I am of the oppinion, that the 3 function-calls are overwriting the content of the field "Cache-Control".
Adding the header-fields in the following sequence leads to the "50%-problem" described above:
CALL METHOD response->set_header_field( name = 'Cache-Control' value  = 'max-age=0' ).
CALL METHOD response->set_header_field( name = 'Cache-Control' value  = 'no-cache' ).
CALL METHOD response->set_header_field( name = 'Cache-Control' value  = 'no-store' ).
Any sequence, in which "no-store" was not the last field added, made the browser read the page from the cache for every click on the back-button.
So i think, that i have to set all of the 3 fields, you suggested, and i am only setting one because every function call overwrites all Cache-Control-Directives.
If my conclusions are right, the field Cache-Control should be sort of a "structure" and i have to set 3 of its fields...
Regards
Jörg Neumann