po plugin: added todo note about optimization

[ikiwiki.git] / doc / plugins / po.mdwn

diff --git a/doc/plugins/po.mdwn b/doc/plugins/po.mdwn
index 0cb510dce9f99285408ad3c3bec008d057bd8de5..f71a36739f18f3f56ad97648d45ba47270b41875 100644 (file)
--- a/doc/plugins/po.mdwn
+++ b/doc/plugins/po.mdwn
@@ -10,8 +10,12 @@ Introduction
 ============
 
 A language is chosen as the "master" one, and any other supported
-language is a "slave" one. A page written in the "master" language is
-a "master" page, and is written in any supported format but PO.
+language is a "slave" one.
+
+A page written in the "master" language is a "master" page, and is
+written in any supported format but PO. It does not have to be named
+a special way: migration from/to this plugin does not imply heavy
+renaming work.
 
 Example: `bla/page.mdwn` is a "master" Markdown page written in
 English; if `usedirs` is enabled, it is rendered as
@@ -42,6 +46,51 @@ languages, such as:
                                 'de' => { 'name' => 'Deutsch', }
         }
 
+Decide which pages are translatable
+-----------------------------------
+
+The subset of "master" pages subject to translation is configurable:
+
+- a `[[!translatable ]]` directive, when put on a page, makes it
+  translatable
+- to set at once a bunch of pages as being translatable, use this
+  [[ikiwiki/directive]] with the `match=PageSpec` argument.
+
+Internal links
+--------------
+
+One can use the `po_link_to_` option in `ikiwiki.setup` to choose how
+internal links should be generated, depending on web server features
+and site-specific preferences.
+
+### Default linking behavior
+
+If `po_link_to` is unset, or set to `default`, ikiwiki's default
+linking behavior is preserved: `[[page]]` links to the master
+language's page.
+
+### Link to negotiated language
+
+If `po_link_to` is set to `negotiated`, `[[page]]` links to the
+negotiated preferred language, *i.e.* `foo/page/`.
+
+(In)compatibility notes:
+
+- `po_link_to => negotiated` provides no useful behavior if `usedirs`
+  is disabled; this option combination is neither implemented nor
+  allowed
+- `po_link_to => negotiated` provides no useful behavior if the web
+  server does not support Content Negotiation
+
+### Link to current language
+
+If `po_link_to` is set to `current` and the destination page is either
+a translatable page or a translation, `[[page]]` links to the current
+page's language, *i.e.*:
+
+- `foo/page/index.LL.html` if `usedirs` is enabled
+- `foo/page.LL.html` if `usedirs` is disabled
+
 
 Server support
 ==============
@@ -73,28 +122,14 @@ lighttpd unfortunately does not support content negotiation.
 TODO
 ====
 
-Links
------
-
-Choice between two behaviors must be possible in `ikiwiki.setup`;
-a `po_link_to_current_language` option must allow switching
-between them.
-
-If `po_link_to_current_language` is disabled, `[[page]]` links to the
-negotiated preferred language, i.e.:
+Optimization
+------------
 
-- `usedirs` enabled: `bla/page/`
-- `usedirs` disabled: `bla/page`
+Move `match_istranslation` and `match_istranslatable` code into helper
+functions, and pre-compute what can be early in the build process:
 
-This obviously does not work in case Content Negotiation is not
-supported by the web server, hence one can enable
-`po_link_to_current_language` to make `[[page]]` link to the current
-page's language, i.e.:
-
-- `usedirs` enabled: `bla/page/index.LL.html`
-- `usedirs` disabled: `bla/page.LL.html`
-
-**FIXME**: should `po_link_to_current_language` be enabled by default?
+- the list of translatable (master) pages
+- for every translatable page, the list of slave pages
 
 Display available translations
 ------------------------------
@@ -115,17 +150,6 @@ implemented as a
 loop, a page using it should depend on any "master" and "slave" pages
 whose status is being displayed.
 
-Decide which pages are translatable
------------------------------------
-
-The subset of "master" pages subject to translation must be
-configurable:
-
-- a `[[!translatable ]]` directive, when put on a page, makes it
-  translatable
-- to set at once a bunch of pages as being translatable, use this
-  [[ikiwiki/directive]] with the `match=PageSpec` argument.
-
 Automatic PO files update
 -------------------------
 
@@ -163,6 +187,8 @@ must be enabled to write:
 
         \[[!map pages="dev/* and lang(LL)" feeds="no"]]
 
+        \[[!map pages="dev/* and currentlang()" feeds="no"]]
+
 Translation quality assurance
 -----------------------------