Re: LYNX-DEV Rendering

[Foteos Macrides]

Duncan Hill <address@hidden> wrote:
>Ok..this just struck me, so sorry for opening an old thread.  I can't 
>ever remember seeing mention of at least one way caching on the rendering 
>of a page. 
>
>If I load a page, alls well.  I want to see the source, so I press \ and 
>off Lynx goes to get the HTML.  No problem,  now I want the rendered 
>version, so I press \ again, and it goes again.  Now, if Lynx has the raw 
>HTML in memory, why does it need to go and get the raw HTML again?  Or 
>did I miss something fundemental in the last thread about this? 

        Lynx does not have the "raw" anything in memory, ever.  When you
fetch the source, to display it Lynx must *render* it (as text/plain) into
an HText structure.  Lynx is *not* a file viewer like more, less or most.
Lynx can save input streams to disk, as it does for ones which will be
passed via a spawn to a helper app.  But it does not save text/html or
text/plain to disk (except for 'd'ownloads, for which you will be passing
the disk copy to a "help app" selected from the download menu, not
displaying it with Lynx).

        To use a disk cache, Lynx should also have a large body of code
implemented for checking and regulating it's expiration, and taking a
large variety of additional considerations into account.  I strongly
recommend that the people who have been on this list for a while, and
keep asking this kind of question, do use the online 'h'elp to access
the HTTP/1.0 and/or HTTP/1.1 Specs, and read at least some of the
thousands of lines in them about caching.

        Note also, that because the major clients now use server-like
caches, a variety of the requirements for cache regulation are implemented
in those clients, and Lynx's blind re-use of its cache-size (normally 10)
HText stores, without first doing those checks, technically is in
violation of the protocol.  All we're checking, as of v2.6, is whether
a no-cache header or META directive was present when the original stream
was received (and whether it was a POSTed form).  In the great majority
of cases on today's Web, relying on nothing more than a no-cache directive
or POST content check is fine, but as the more elaborate HTTP/1.1
Cache-Control, Expires, and other headers become more widely used, what
Lynx is doing won't be fine.

                                Fote

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