Extended URL Mapping
The previous section sets up remapping of HTML URLs, but leaves any
URL encountered in a Stylesheet or Script untouched. mod_proxy_html
doesn't parse Javascript or CSS, so dealing with URLs in them requires
text-based search-and-replace. This is enabled by the directive
ProxyHTMLExtended On.
Because the extended mode is text-based, it can no longer guarantee to
match exact URLs. It's up to you to devise matching rules that can
pick out URLs, just as if you were writing an old-fashioned Perl or
PHP regexp-based filter (though of course it's still massively more
efficient than performing search-and-replace on an entire document
in-memory). To help with this, ProxyHTMLExtended supports both simple
text-based and regular expression search-and-replace, according to the
flags. You can also use the flags to specify rules separately for HTML
links, scripting events, and embedded scripts and stylesheets.
A second key consideration with extended URL mapping is that whereas
an HTML link contains exactly one URL, a script or stylesheet may
contain many. So instead of stopping after a successful match, the
processor will apply all applicable mapping rules. This can be stopped
with the L (last) flag.
