@item{Within this submodule, use @racket[define] to make a variable with the same name as the one in @racket[pollen/setup], but without the @racket[setup:] prefix.}
For instance, suppose you wanted the main export of every Pollen source file to be called @racket[van-halen] rather than @racket[doc], the extension of Pollen markup files to be @racket[.rock] rather than @racket[.pm], and the command character to be @litchar{🎸} instead of @litchar{◊}. Your @racket["pollen.rkt"] would look like this:
Every @racket[setup:]@racket[_name] function will resolve the current value of that variable: it will return the value from the @racket[setup] submodule (if @racket[_name] was defined there), otherwise it will return the default value (which is directly available from @racket[default-]@racket[_name]). For instance, @racket[default-command-char] will always be @litchar{◊}, but in the example above, @racket[(setup:command-char)] would return@litchar{🎸}.
@defoverridable[block-tags (listof symbol?)]{Tags that are treated as blocks by @racket[block-txexpr?]. Initialized to the @link["https://developer.mozilla.org/en-US/docs/Web/HTML/Block-level_elements"]{block-level elements in HTML5}, namely:
@defoverridable[render-cache-active boolean?]{Whether the render cache, which speeds up interactive sessions by reusing rendered versions of Pollen output files, is active.}
@defoverridable[compile-cache-active boolean?]{Whether the compile cache, which speeds up interactive sessions by saving compiled versions of Pollen source files, is active.}
@defoverridable[cache-watchlist (listof (or/c path? path-string?))]{List of extra files that the cache (= render cache + compile cache, collectively) watches during a project-server session. If one of the files on the watchlist changes, the cache is invalidated (just as it would be if @racket["pollen.rkt"] changed).
If the cache can't find a certain file on the watchlist, no error will arise. The file will simply be ignored. Therefore, to avoid unexpected behavior, the best policy is to use complete paths (or path strings). One way to generate a complete path to a local file is with @racket[define-runtime-path]. Another way, if you're using a module that's already installed as part of a package, is with @racket[resolve-module-path]:
@defoverridable[envvar-watchlist (listof string?)]{List of extra environment variables that are used in cache keys. Separate caches will be maintained for each distinct value of an environment variable. @secref["The_POLLEN_environment_variable"] is always used, regardless of how this value is set.
Both the names and the values of environment variables are case-insensitive, so @racket["PUB"] and @racket["pub"] and @racket["pUb"] are all treated the same.
@defoverridable[publish-directory (or/c path-string? path-for-some-system?)]{Default target for @secref{raco_pollen_publish}. A complete path is used as is; a relative path is published to the desktop.. @history[#:added "1.1"]}
@defoverridable[omitted-path? (path? . -> . boolean?)]{Predicate that determines whether a path is omitted from @secref{raco_pollen_render} and @secref{raco_pollen_publish} operations. If the predicate evaluated to @racket[#t], then the path is omitted.
@defoverridable[extra-path? (path? . -> . boolean?)]{Predicate that determines if path is rendered & published, overriding @racket[(setup:omitted-path?)] above, and Pollen's default publish settings. For instance, Pollen automatically omits files with a @racket[.rkt] extension. If you wanted to force a @racket[.rkt] file to be published, you could include it here.
@defoverridable[index-pages (listof string?)]{List of strings that the project server will use as directory default pages, in order of priority. Has no effect on command-line rendering operations. Also has no effect on your live web server (usually that's a setting you need to make in an @tt{.htaccess} configuration file).} But with this setting, you can simulate the behavior of your live server, so that internal index-page URLs work correctly.
@defoverridable[trim-whitespace? boolean?]{Predicate that controls whether the Pollen source reader trims whitespace from the beginning of a @racket[doc] export. You might set this to @racket[#false] if you're using Pollen as a preprocessor for another programming language and you want to preserve leading whitespace accurately.
@defoverridable[allow-unbound-ids? boolean?]{Predicate that controls whether Pollen converts unbound identifiers into default tags by altering the behavior of @racket[#%top] in @racketmodname[pollen/top].