add pagespec/sorting to underlay

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

diff --git a/doc/plugins/write.mdwn b/doc/plugins/write.mdwn
index 1a119b99b679498c5188620a56e9d7fce81c5bc6..f6ea76c3607fca1104ae9d999799d8e693c598ca 100644 (file)
--- a/doc/plugins/write.mdwn
+++ b/doc/plugins/write.mdwn
@@ -98,7 +98,7 @@ function is passed no values.
 
 This allows a plugin to manipulate the list of files that need to be
 built when the wiki is refreshed. The function is passed a reference to an
 
 This allows a plugin to manipulate the list of files that need to be
 built when the wiki is refreshed. The function is passed a reference to an

-array of pages that will be rebuilt, and can modify the array, either
+array of files that will be rebuilt, and can modify the array, either

 adding or removing files from it.
 
 ### scan
 adding or removing files from it.
 
 ### scan


@@ -107,8 +107,8 @@ adding or removing files from it.
 
 This hook is called early in the process of building the wiki, and is used
 as a first pass scan of the page, to collect metadata about the page. It's
 
 This hook is called early in the process of building the wiki, and is used
 as a first pass scan of the page, to collect metadata about the page. It's

-mostly used to scan the page for WikiLinks, and add them to `%links`.
-Present in IkiWiki 2.40 and later.
+mostly used to scan the page for [[WikiLinks|ikiwiki/WikiLink]], and add
+them to `%links`. Present in IkiWiki 2.40 and later.

 
 The function is passed named parameters "page" and "content". Its return
 value is ignored.
 
 The function is passed named parameters "page" and "content". Its return
 value is ignored.


@@ -151,11 +151,11 @@ 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
 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.)
+hook modifies data in `%links` (typically by calling `add_link`). 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
 preprocessor [[ikiwiki/directive]] output is sanitised, which may limit what
 
 Note that if the [[htmlscrubber]] is enabled, html in
 preprocessor [[ikiwiki/directive]] output is sanitised, which may limit what


@@ -168,13 +168,14 @@ htmlize the page) along with the rest of the page.
 
        hook(type => "linkify", id => "foo", call => \&linkify);
 
 
        hook(type => "linkify", id => "foo", call => \&linkify);
 

-This hook is called to convert [[WikiLinks|WikiLink]] on the page into html
+This hook is called to convert [[WikiLinks|ikiwiki/WikiLink]] on the page into html

 links. The function is passed named parameters "page", "destpage", and
 "content". It should return the linkified content.  Present in IkiWiki 2.40
 and later.
 
 Plugins that implement linkify must also implement a scan hook, that scans
 links. The function is passed named parameters "page", "destpage", and
 "content". It should return the linkified content.  Present in IkiWiki 2.40
 and later.
 
 Plugins that implement linkify must also implement a scan hook, that scans

-for the links on the page and adds them to `%links`.
+for the links on the page and adds them to `%links` (typically by calling
+`add_link`).

 
 ### htmlize
 
 
 ### htmlize
 


@@ -189,9 +190,17 @@ The function is passed named parameters: "page" and "content" and should
 return the htmlized content.
 
 If `hook` is passed an optional "keepextension" parameter, set to a true
 return the htmlized content.
 
 If `hook` is passed an optional "keepextension" parameter, set to a true

-value, then this extension will not be stripped from the source filename when
+value, then the extension will not be stripped from the source filename when

 generating the page.
 
 generating the page.
 

+If `hook` is passed an optional "noextension" parameter, set to a true
+value, then the id parameter specifies not a filename extension, but
+a whole filename that can be htmlized. This is useful for files
+like `Makefile` that have no extension.
+
+If `hook` is passed an optional "longname" parameter, this value is used
+when prompting a user to choose a page type on the edit page form.
+

 ### pagetemplate
 
        hook(type => "pagetemplate", id => "foo", call => \&pagetemplate);
 ### pagetemplate
 
        hook(type => "pagetemplate", id => "foo", call => \&pagetemplate);


@@ -321,6 +330,26 @@ This hook should avoid directly redirecting the user to a signin page,
 since it's sometimes used to test to see which pages in a set of pages a
 user can edit.
 
 since it's sometimes used to test to see which pages in a set of pages a
 user can edit.
 

+### canremove
+
+       hook(type => "canremove", id => "foo", call => \&canremove);
+
+This hook can be used to implement arbitrary access methods to control
+when a page can be removed using the web interface (commits from
+revision control bypass it). It works exactly like the `canedit` hook,
+but is passed the named parameters `cgi` (a CGI object), `session`
+(a session object) and `page` (the page subject to deletion).
+
+### canrename
+
+       hook(type => "canrename", id => "foo", call => \&canrename);
+
+This hook can be used to implement arbitrary access methods to control when
+a page can be renamed using the web interface (commits from revision control
+bypass it). It works exactly like the `canedit` hook,
+but is passed the named parameters `cgi` (a CGI object), `session` (a
+session object), `src`, `srcfile`, `dest` and `destfile`.
+

 ### checkcontent
        
        hook(type => "checkcontent", id => "foo", call => \&checkcontent);
 ### checkcontent
        
        hook(type => "checkcontent", id => "foo", call => \&checkcontent);


@@ -333,8 +362,9 @@ the content the user has entered is a comment, it may also be passed some
 additional parameters: `author`, `url`, and `subject`. The `subject`
 parameter may also be filled with the user's comment about the change.
 
 additional parameters: `author`, `url`, and `subject`. The `subject`
 parameter may also be filled with the user's comment about the change.
 

-Note: When the user edits an existing wiki page, the passed `content` will
-include only the lines that they added to the page, or modified.
+Note: When the user edits an existing wiki page, this hook is also
+passed a `diff` named parameter, which will include only the lines
+that they added to the page, or modified.

 
 The hook should return `undef` on success. If the content is disallowed, it
 should return a message stating what the problem is, or a function
 
 The hook should return `undef` on success. If the content is disallowed, it
 should return a message stating what the problem is, or a function


@@ -385,9 +415,28 @@ they're saved, etc.
        hook(type => "renamepage", id => "foo", call => \&renamepage);
 
 This hook is called by the [[plugins/rename]] plugin when it renames
        hook(type => "renamepage", id => "foo", call => \&renamepage);
 
 This hook is called by the [[plugins/rename]] plugin when it renames

-something. The hook is passed named parameters: `page`, `oldpage`,
-`newpage`, and `content`, and should try to modify the content to reflect
-the name change. For example, by converting links to point to the new page.
+something, once per page linking to the renamed page's old location.
+The hook is passed named parameters: `page`, `oldpage`, `newpage`, and
+`content`, and should try to modify the content of `page` to reflect
+the name change. For example, by converting links to point to the
+new page.
+
+### rename
+
+       hook(type => "rename", id => "foo", call => \&rename);
+
+When a page or set of pages is renamed, the referenced function is
+called for every page, and is passed named parameters:
+
+* `torename`: a reference to a hash with keys: `src`, `srcfile`,
+  `dest`, `destfile`, `required`.
+* `cgi`: a CGI object
+* `session`: a session object.
+
+Such a hook function returns any additional rename hashes it wants to
+add. This hook is applied recursively to returned additional rename
+hashes, so that it handles the case where two plugins use the hook:
+plugin A would see when plugin B adds a new file to be renamed.

 
 ### getsetup
 
 
 ### getsetup
 


@@ -434,7 +483,7 @@ describes the plugin as a whole. For example:
 * `example` can be set to an example value.
 * `description` is a short description of the option.
 * `link` is a link to further information about the option. This can either
 * `example` can be set to an example value.
 * `description` is a short description of the option.
 * `link` is a link to further information about the option. This can either

-  be a wikilink, or an url.
+  be a [[ikiwiki/WikiLink]], or an url.

 * `advanced` can be set to true if the option is more suitable for advanced
   users.
 * `safe` should be false if the option should not be displayed in unsafe
 * `advanced` can be set to true if the option is more suitable for advanced
   users.
 * `safe` should be false if the option should not be displayed in unsafe


@@ -447,6 +496,13 @@ describes the plugin as a whole. For example:
   and undef if a rebuild could be needed in some circumstances, but is not
   strictly required.
 
   and undef if a rebuild could be needed in some circumstances, but is not
   strictly required.
 

+### genwrapper
+
+       hook(type => "genwrapper", id => "foo", call => \&genwrapper);
+
+This hook is used to inject C code (which it returns) into the `main`
+function of the ikiwiki wrapper when it is being generated.
+

 ## Plugin interface
 
 To import the ikiwiki plugin interface:
 ## Plugin interface
 
 To import the ikiwiki plugin interface:


@@ -553,15 +609,67 @@ page created from it. (Ie, it appends ".html".)
 Use this when constructing the filename of a html file. Use `urlto` when
 generating a link to a page.
 
 Use this when constructing the filename of a html file. Use `urlto` when
 generating a link to a page.
 

-#### `add_depends($$)`
+### `deptype(@)`
+
+Use this function to generate ikiwiki's internal representation of a
+dependency type from one or more of these keywords:
+
+* `content` is the default. Any change to the content
+  of a page triggers the dependency.
+* `presence` is only triggered by a change to the presence
+  of a page.
+* `links` is only triggered by a change to the links of a page.
+  This includes when a link is added, removed, or changes what
+  it points to due to other changes. It does not include the
+  addition or removal of a duplicate link.
+
+If multiple types are specified, they are combined.
+
+#### `pagespec_match_list($$;@)`
+
+Passed a page name, and [[ikiwiki/PageSpec]], returns a list of pages
+in the wiki that match the [[ikiwiki/PageSpec]]. 
+
+The page will automatically be made to depend on the specified
+[[ikiwiki/PageSpec]], so `add_depends` does not need to be called. This
+is significantly more efficient than calling `add_depends` and
+`pagespec_match` in a loop. You should use this anytime a plugin
+needs to match a set of pages and do something based on that list.
+
+Additional named parameters can be specified:
+
+* `deptype` optionally specifies the type of dependency to add. Use the
+  `deptype` function to generate a dependency type.
+* `limit` is a reference to a function, that is called and passed a page,
+  and must return true for the page to be included.
+* `sort` specifies a sort order for the list. See
+  [[ikiwiki/PageSpec/sorting]] for the avilable sort methods.
+* `reverse` if true, sorts in reverse.
+* `num` if nonzero, specifies the maximum number of matching pages that
+  will be returned.
+* `list` makes it only match amoung the specified list of pages.
+  Default is to match amoung all pages in the wiki.
+
+Unlike pagespec_match, this may throw an error if there is an error in
+the pagespec.
+
+#### `add_depends($$;$)`

 
 Makes the specified page depend on the specified [[ikiwiki/PageSpec]].
 
 
 Makes the specified page depend on the specified [[ikiwiki/PageSpec]].
 

+By default, dependencies are full content dependencies, meaning that the
+page will be updated whenever anything matching the PageSpec is modified.
+This can be overridden by passing a `deptype` value as the third parameter.
+

 #### `pagespec_match($$;@)`
 
 #### `pagespec_match($$;@)`
 

-Passed a page name, and [[ikiwiki/PageSpec]], returns true if the
+Passed a page name, and [[ikiwiki/PageSpec]], returns a true value if the

 [[ikiwiki/PageSpec]] matches the page.
 
 [[ikiwiki/PageSpec]] matches the page.
 

+Note that the return value is overloaded. If stringified, it will be a
+message indicating why the PageSpec succeeded, or failed, to match the
+page.
+

 Additional named parameters can be passed, to further limit the match.
 The most often used is "location", which specifies the location the
 PageSpec should match against. If not passed, relative PageSpecs will match
 Additional named parameters can be passed, to further limit the match.
 The most often used is "location", which specifies the location the
 PageSpec should match against. If not passed, relative PageSpecs will match


@@ -579,7 +687,7 @@ pages, as described in [[ikiwiki/SubPage/LinkingRules]].
 
 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

-`htmlllink` is:
+`htmllink` is:

 
        htmllink($page, $page, $link)
 
 
        htmllink($page, $page, $link)
 


@@ -680,7 +788,7 @@ a wiki page name.
 #### `linkpage($)`
 
 This converts text that could have been entered by the user as a
 #### `linkpage($)`
 
 This converts text that could have been entered by the user as a

-[[WikiLink]] into a wiki page name.
+[[ikiwiki/WikiLink]] into a wiki page name.

 
 #### `srcfile($;$)`
 
 
 #### `srcfile($;$)`
 


@@ -735,6 +843,11 @@ Optionally, a third parameter can be passed, to specify the preferred
 filename of the page. For example, `targetpage("foo", "rss", "feed")`
 will yield something like `foo/feed.rss`.
 
 filename of the page. For example, `targetpage("foo", "rss", "feed")`
 will yield something like `foo/feed.rss`.
 

+#### `add_link($$)`
+
+This adds a link to `%links`, ensuring that duplicate links are not
+added. Pass it the page that contains the link, and the link text.
+

 ## Miscellaneous
 
 ### Internal use pages
 ## Miscellaneous
 
 ### Internal use pages


@@ -745,7 +858,7 @@ are collected together to form the RecentChanges page, for example.
 
 To make an internal use page, register a filename extension that starts
 with "_". Internal use pages cannot be edited with the web interface,
 
 To make an internal use page, register a filename extension that starts
 with "_". Internal use pages cannot be edited with the web interface,

-generally shouldn't contain wikilinks or preprocessor directives (use
+generally shouldn't contain [[WikiLinks|ikiwiki/WikiLink]] or preprocessor directives (use

 either on them with extreme caution), and are not matched by regular
 PageSpecs glob patterns, but instead only by a special `internal()`
 [[ikiwiki/PageSpec]].
 either on them with extreme caution), and are not matched by regular
 PageSpecs glob patterns, but instead only by a special `internal()`
 [[ikiwiki/PageSpec]].


@@ -783,7 +896,7 @@ of the page with the rcs's conflict markers on failure.
 Passed a message, user, and ip address. Should commit all staged changes.
 Returns undef on success, and an error message on failure.
 
 Passed a message, user, and ip address. Should commit all staged changes.
 Returns undef on success, and an error message on failure.
 

-Changes can be staged by calls to `rcs_add, `rcs_remove`, and
+Changes can be staged by calls to `rcs_add`, `rcs_remove`, and

 `rcs_rename`.
 
 #### `rcs_add($)`
 `rcs_rename`.
 
 #### `rcs_add($)`


@@ -885,9 +998,21 @@ It's also possible to write plugins that add new functions to
 IkiWiki::PageSpec package, that is named `match_foo`, where "foo()" is
 how it will be accessed in a [[ikiwiki/PageSpec]]. The function will be passed
 two parameters: The name of the page being matched, and the thing to match
 IkiWiki::PageSpec package, that is named `match_foo`, where "foo()" is
 how it will be accessed in a [[ikiwiki/PageSpec]]. The function will be passed
 two parameters: The name of the page being matched, and the thing to match

-against. It may also be passed additional, named parameters. It should return
-a IkiWiki::SuccessReason object if the match succeeds, or an
-IkiWiki::FailReason object if the match fails.
+against. It may also be passed additional, named parameters.
+
+It should return a IkiWiki::SuccessReason object if the match succeeds, or
+an IkiWiki::FailReason object if the match fails. If the match cannot be
+attempted at all, for any page, it can instead return an
+IkiWiki::ErrorReason object explaining why.
+
+When constructing these objects, you should also include information about
+of any pages whose contents or other metadata influenced the result of the
+match. Do this by passing a list of pages, followed by `deptype` values.
+
+For example, "backlink(foo)" is influenced by the contents of page foo;
+"link(foo)" and "title(bar)" are influenced by the contents of any page
+they match; "created_before(foo)" is influenced by the metadata of foo;
+while "glob(*)" is not influenced by the contents of any page.

 
 ### Setup plugins
 
 
 ### Setup plugins
 


@@ -914,7 +1039,7 @@ or wrap one of the functions.
 For example, your plugin might want to override `displaytime`, to change
 the html markup used when displaying a date. Or it might want to override
 `IkiWiki::formattime`, to change how a date is formatted. Or perhaps you
 For example, your plugin might want to override `displaytime`, to change
 the html markup used when displaying a date. Or it might want to override
 `IkiWiki::formattime`, to change how a date is formatted. Or perhaps you

-want to override `bestlink` and change how ikiwiki deals with WikiLinks.
+want to override `bestlink` and change how ikiwiki deals with [[WikiLinks|ikiwiki/WikiLink]].

 
 By venturing into this territory, your plugin is becoming tightly tied to
 ikiwiki's internals. And it might break if those internals change. But
 
 By venturing into this territory, your plugin is becoming tightly tied to
 ikiwiki's internals. And it might break if those internals change. But