You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
pollen/scribblings/render.scrbl

89 lines
4.7 KiB
Racket

This file contains invisible Unicode characters!

This file contains invisible Unicode characters that may be processed differently from what appears below. If your use case is intentional and legitimate, you can safely ignore this warning. Use the Escape button to reveal hidden characters.

#lang scribble/manual
@(require scribble/eval pollen/render pollen/world (for-label racket (except-in pollen #%module-begin) pollen/world web-server/templates pollen/file sugar pollen/render))
@(define my-eval (make-base-eval))
@(my-eval `(require pollen))
@title{Render}
@defmodule[pollen/render]
@italic{Rendering} is how Pollen source files get converted into output.
@defproc[
(render
[source-path complete-path?]
[template-path (or/c #f complete-path?) #f])
bytes?]
Renders @racket[_source-path]. The rendering behavior depends on the type of source file (for details, see @secref["File_formats" #:doc '(lib "pollen/scribblings/pollen.scrbl")]):
A @racketmodname[pollen/pre] file is rendered without a template.
A @racketmodname[pollen/markup] or @racketmodname[pollen/markdown] file is rendered with a template. If no template is specified with @racket[_template-path], Pollen tries to find one using @racket[get-template-for].
Be aware that rendering with a template uses @racket[include-template] within @racket[eval]. For complex pages, it can be slow the first time. Caching is used to make subsequent requests faster.
For those panicked at the use of @racket[eval], please don't be. As the author of @racket[include-template] has already advised, ``If you insist on dynamicism'' and yes, I do insist ``@link["http://docs.racket-lang.org/web-server/faq.html#%28part._.How_do_.I_use_templates__dynamically__%29"]{there is always @racket[eval].}''
@defproc[
(render-to-file
[source-path complete-path?]
[template-path (or/c #f complete-path?) #f]
[output-path (or/c #f complete-path?) #f])
void?]
Like @racket[render], but saves the file to @racket[_output-path], overwriting whatever was already there. If no @racket[_output-path] is provided, it's derived from @racket[_source-path] using @racket[->output-path].
@defproc[
(render-to-file-if-needed
[source-path complete-path?]
[template-path (or/c #f complete-path?) #f]
[output-path (or/c #f complete-path?) #f]
[#:force force-render? boolean? #f])
void?]
Like @racket[render-to-file], but the render only happens if one of these conditions exist:
@itemlist[#:style 'ordered
@item{The @racket[_force-render?] flag  set with the @racket[#:force] keyword is @racket[#t].}
@item{No file exists at @racket[_output-path]. (Thus, an easy way to force a render of a particular @racket[_output-path] is to delete it.)}
@item{Either @racket[_source-path] or @racket[_template-path] have changed since the last trip through @racket[render].}
@item{One or more of the project requires have changed.}]
If none of these conditions exist, @racket[_output-path] is deemed to be up to date, and the render is skipped.
@defproc[
(render-batch
[source-paths (listof pathish?)] ...)
void?]
Render multiple @racket[_source-paths] in one go. This can be faster than @racket[(for-each render _source-paths)] if your @racket[_source-paths] rely on a common set of templates. Templates may have their own source files that need to be compiled. If you use @racket[render], the templates will be repeatedly (and needlessly) re-compiled. Whereas if you use @racket[render-batch], each template will only be compiled once.
@defproc*[
(
[(render-pagetree [pagetree pagetree?]) void?]
[(render-pagetree [pagetree-source pathish?]) void?])]
Using @racket[_pagetree], or a pagetree loaded from @racket[_pagetree-source], render the pages in that pagetree using @racket[render-batch].
Note that @racket[_pagetree] or @racket[_pagetree_source] is used strictly as a list of files to render. It is not used, for instance, as the navigational pagetree for the rendered files.
@defproc[
(get-template-for
[source-path complete-path?])
(or/c #f complete-path?)]
Find a template file for @racket[_source-path], with the following priority:
@itemlist[#:style 'ordered
@item{If the @racket[metas] for @racket[_source-path] have a key for @code[(format "~a" world:template-meta-key)], then use the value of this key.}
@item{If this key doesn't exist, or if it points to a nonexistent file, look for a default template in the project directory with the name @code[(format "~a.[output extension]" world:default-template-prefix)]. Meaning, if @racket[_source-path] is @code[(format "intro.html.~a" world:markup-source-ext)], the output path would be @code["intro.html"], so the default template would be @code[(format "~a.html" world:default-template-prefix)].}
@item{If this file doesn't exist, use the fallback template as a last resort. (See @secref["Templates"
#:tag-prefixes '("tutorial-2")
#:doc '(lib "pollen/scribblings/pollen.scrbl")].)}
]
This function is called when a template is needed, but a @racket[_template-path] argument is missing (for instance, in @racket[render] or @racket[render-to-file]).