A parameter that holds the root directory of the current project (e.g., the directory where you launched @code{raco pollen start}).}
@defparam[world:current-server-extras-path dir path?]{
A parameter that reports the path to the directory of support files for the project server. Initialized to @racket[#f], but set to a proper value when the server runs.}
A parameter that determines whether the @racket[world:directory-require] file is checked for changes on every pass through @racket[render]. (Can be faster to turn this off if you don't need it.) Initialized to @racket[#t].}
@section{Values that can be overwritten with @racket[local:]}
These values can be changed by overriding them in your @racket["directory-require.rkt"] source file. Use @racket[define] to make a variable with the same name as the one in @racket[pollen/world], but with the prefix @racket[local:] instead of @racket[world:]. Assign it whatever value you like. When Pollen runs, these definitions will supersede those in @racket[pollen/world].
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["directory-require.rkt"] would include these defintions:
@fileblock["directory-require.rkt"
@codeblock{
#lang racket/base
(provide (all-defined-out))
(define local:main-export 'van-halen)
(define local:markup-source-ext 'rock)
(define local:command-char #\🎸)
}]
Though any of the values below can be overridden, it may not always be wise to do so. For instance, if you redefined @racket[world:fallback-template-prefix], you would simply break the fallback-template mechanism, because it would look for files that don't exist. But we don't live in a nanny state, so you are entrusted to say what you mean and accept the consequences.
Of course, you can restore the defaults simply by deleting these defined values from @racket["directory-require.rkt"].
These overridable values also come with a corresponding @racket[get-] function that will return the @racket[local:] value if it exists, otherwise the @racket[world:] value. In the example above, @racket[world:command-char] would be @litchar{◊} no matter what, but @racket[world:get-command-char] would return @litchar{🎸}.
@defoverridable[default-port integer?]{
Determines the default HTTP port for the project server. Initialized to @racket[8080].}
@defoverridable[main-export symbol?]{The main X-expression exported from a compiled Pollen source file. Initialized to @racket[doc].}
@defoverridable[meta-export symbol?]{The meta hashtable exported from a compiled Pollen source file. Initialized to @racket[metas].}
@defoverridable[world:meta-tag-name symbol?]{Name of the tag used to mark metas within Pollen source.}
@defoverridable[world:directory-require string?]{File implicitly required into every Pollen source file from its directory. Initialized to @filepath{directory-require.rkt}.}
@defoverridable[world:server-extras-dir string?]{Name of directory where server support files live. Initialized to @tt{server-extras}.}
@defoverridable[pagetree-root-node symbol?]{Name of the root node in a decoded pagetree. It's ignored by the code, so its only role is to clue you in that you're looking at something that came out of the pagetree decoder. Initialized to @code{'pagetree-root}.}
@defoverridable[fallback-template-prefix string?]{Used to generate the name of the fallback template (i.e., the template used to render a Pollen markup file when no other template can be found). Prefix is combined with the output suffix of the source file. Initialized to @code{"fallback"}.}