support previewing of sparklines: embed in data uris for preview

[git.ikiwiki.info.git] / doc / plugins / write.mdwn

diff --git a/doc/plugins/write.mdwn b/doc/plugins/write.mdwn
index d0f256ca293aaeaf21fd398906771f9db8cd831f..5547ae6999d5a70de49f01b70c2f650bc7396ebd 100644 (file)
--- a/doc/plugins/write.mdwn
+++ b/doc/plugins/write.mdwn
@@ -96,9 +96,11 @@ 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
 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). 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 directive.
+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
+directive.

 
 Note that if the [[htmlscrubber]] is enabled, html in
 [[PreProcessorDirective]] output is sanitised, which may limit what your
 
 Note that if the [[htmlscrubber]] is enabled, html in
 [[PreProcessorDirective]] output is sanitised, which may limit what your


@@ -287,9 +289,11 @@ the id can be controled by the user.
 Logs a debugging message. These are supressed unless verbose mode is turned
 on.
 
 Logs a debugging message. These are supressed unless verbose mode is turned
 on.
 

-#### `error($)`
+#### `error($;$)`

 
 

-Aborts with an error message.
+Aborts with an error message. If the second parameter is passed, it is a
+function that is called after the error message is printed, to do any final
+cleanup.

 
 Note that while any plugin can use this for a fatal error, plugins should
 try to avoid dying on bad input, as that will halt the entire wiki build
 
 Note that while any plugin can use this for a fatal error, plugins should
 try to avoid dying on bad input, as that will halt the entire wiki build


@@ -312,10 +316,12 @@ page created from it. (Ie, it appends ".html".)
 
 Makes the specified page depend on the specified [[PageSpec]].
 
 
 Makes the specified page depend on the specified [[PageSpec]].
 

-#### `pagespec_match($$)`
+#### `pagespec_match($$;$)`

 
 

-Passed a page name, and a [[PageSpec]], returns true if the [[PageSpec]]
-matches the page.
+Passed a page name, a [[PageSpec]], and the location the [[PageSpec]] should
+be matched against, returns true if the [[PageSpec]] matches the page. (If
+the third parameter is not passed, relative PageSpecs will match relative to
+the top of the wiki.)

 
 #### `bestlink($$)`
 
 
 #### `bestlink($$)`
 


@@ -325,7 +331,7 @@ subdirectory with the same name as the source page, failing that
 goes down the directory tree to the base looking for matching
 pages, as described in [[SubPage/LinkingRules]].
 
 goes down the directory tree to the base looking for matching
 pages, as described in [[SubPage/LinkingRules]].
 

-#### `htmllink($$$;$$$)`
+#### `htmllink($$$;@)`

 
 Many plugins need to generate html links and add them to a page. This is
 done by using the `htmllink` function. The usual way to call
 
 Many plugins need to generate html links and add them to a page. This is
 done by using the `htmllink` function. The usual way to call


@@ -342,11 +348,13 @@ Here `$destpage` is the inlining page. A `destpage` parameter is passed to
 some of the hook functions above; the ones that are not passed it are not used
 during inlining and don't need to worry about this issue.
 
 some of the hook functions above; the ones that are not passed it are not used
 during inlining and don't need to worry about this issue.
 

-The remaining three optional parameters to `htmllink` are:
+After the three required parameters, named parameters can be used to
+control some options. These are:

 
 

-1. noimageinline - set to true to avoid turning links into inline html images
-1. forcesubpage  - set to force a link to a subpage
-1. linktext - set to force the link text to something
+* noimageinline - set to true to avoid turning links into inline html images
+* forcesubpage  - set to force a link to a subpage
+* linktext - set to force the link text to something
+* anchor - set to make the link include an anchor

 
 #### `readfile($;$)`
 
 
 #### `readfile($;$)`
 


@@ -357,14 +365,20 @@ in binary mode.
 
 A failure to read the file will result in it dying with an error.
 
 
 A failure to read the file will result in it dying with an error.
 

-#### `writefile($$$;$)`
+#### `writefile($$$;$$)`

 
 Given a filename, a directory to put it in, and the file's content,
 writes a file. 
 
 
 Given a filename, a directory to put it in, and the file's content,
 writes a file. 
 

-The optional second parameter, if set to a true value, makes the file be
+The optional fourth parameter, if set to a true value, makes the file be

 written in binary mode.
 
 written in binary mode.
 

+The optional fifth parameter can be used to pass a function reference that
+will be called to handle writing to the file. The function will be called
+and passed a file descriptor it should write to, and an error recovery
+function it should call if the writing fails. (You will not normally need to
+use this interface.)
+

 A failure to write the file will result in it dying with an error.
 
 If the destination directory doesn't exist, it will first be created.
 A failure to write the file will result in it dying with an error.
 
 If the destination directory doesn't exist, it will first be created.


@@ -411,3 +425,12 @@ See IkiWiki::RCS::Stub for the full list of functions. It's ok if
 rcs\_getctime does nothing except for throwing an error.
 
 See [[about_RCS_backends]] for some more info.
 rcs\_getctime does nothing except for throwing an error.
 
 See [[about_RCS_backends]] for some more info.

+
+## PageSpec plugins
+
+It's also possible to write plugins that add new functions to
+[[PageSpecs|PageSpec]]. Such a plugin should add a function to the
+IkiWiki::PageSpec package, that is named `match_foo`, where "foo()" is
+how it will be accessed in a [[PageSpec]]. The function will be passed two
+parameters: The name of the page being matched, and the thing to match
+against. It should return true if the page matches.