diff options
| -rw-r--r-- | doc/plugins/write.mdwn | 44 |
1 files changed, 26 insertions, 18 deletions
diff --git a/doc/plugins/write.mdwn b/doc/plugins/write.mdwn index 7c28088de..58c04d97a 100644 --- a/doc/plugins/write.mdwn +++ b/doc/plugins/write.mdwn @@ -128,26 +128,34 @@ of a plugin. hook(type => "preprocess", id => "foo", call => \&preprocess); -Replace "foo" with the command name that will be used inside brackets for -the preprocessor directive. - -Each time the directive is processed, the referenced function (`preprocess` -in the example above) is called, and is passed named parameters. A "page" -parameter gives the name of the page that embedded the preprocessor -directive, while a "destpage" parameter gives the name of the page the -content is going to (different for inlined pages), and a "preview" -parameter is set to a true value if the page is being previewed. All -parameters included in the directive are included as named parameters as -well. Whatever the function returns goes onto the page in place of the +Replace "foo" with the command name that will be used for the preprocessor directive. -An optional "scan" parameter, if set to a true value, makes the hook be -called during the preliminary scan that ikiwiki makes of updated pages, -before begining to render pages. This parameter should be set to true if -the hook modifies data in `%links`. Note that doing so will make the hook -be run twice per page build, so avoid doing it for expensive hooks. (As an -optimisation, if your preprocessor hook is called in a void contets, you -can assume it's being run in scan mode.) +Each time the directive is processed, the referenced function (`preprocess` +in the example above) is called. Whatever the function returns goes onto +the page in place of the directive. Or, if the function aborts using +`error()`, the directive will be replaced with the error message. + +The function is passed named parameters. First come the parameters set +in the preprocessor directive. These are passed in the same order as +they're in the directive, and if the preprocessor directive contains a bare +parameter (example: `\[[!foo param]]`), that parameter will be passed with +an empty value. + +After the parameters from the preprocessor directive some additional ones +are passed: A "page" parameter gives the name of the page that embedded the +preprocessor directive, while a "destpage" parameter gives the name of the +page the content is going to (different for inlined pages), and a "preview" +parameter is set to a true value if the page is being previewed. + +If `hook` is passed an optional "scan" parameter, set to a true value, this +makes the hook be called during the preliminary scan that ikiwiki makes of +updated pages, before begining to render pages. This should be done if the +hook modifies data in `%links`. Note that doing so will make the hook be +run twice per page build, so avoid doing it for expensive hooks. (As an +optimisation, if your preprocessor hook is called in a void context, you +can assume it's being run in scan mode, and avoid doing expensive things at +that point.) Note that if the [[htmlscrubber]] is enabled, html in [[ikiwiki/PreProcessorDirective]] output is sanitised, which may limit what |