NAME¶
wml::std::lang - Multi-Lingual Support
SYNOPSIS¶
#use wml::std::lang
<lang:new id=xx [short]>
<lang:area>
(xx) ... (yy) ...
</lang:area>
<lang:set-wildcard ...>
<lang:star: ...*..>
<lang:star:href: index.*.html|index.html>
<lang:star:slice: index.*.html>
<lang:xx>...</lang:xx>
<lang:xx: ...>
<xx>...</xx>
<xx: ...>
<lang:current>
<lang:list>
DESCRIPTION¶
This include file provides high-level multi-lingual support via Slices. Its
purpose is to define the slices ``"LANG_XX"'' according to the
multi-lingual selection tags.
The general intend of this slice-based approach is to use the defined slices in
Pass 9 (Slice) via WMLs
-o option. A typical shebang-line example for
the use with a webserver's content negotiation feature is:
#!wml -o (ALL-LANG_*)+LANG_EN:index.html.en \
-o (ALL-LANG_*)+LANG_DE:index.html.de
Since WML 1.7.0, the "<lang:star:slice:>" tag is an alternative
to this shebang-line.
Before you can use a language, you have to define the corresponding tags via
"<lang:new>". For instance when you want to use the languages
english and german, use:
<lang:new id=en>
<lang:new id=de>
Then the following tags are defined:
<lang:en>...</lang:en>
<lang:de>...</lang:de>
<lang:en: ...>
<lang:de: ...>
i.e. for both languages a container tag and a simple tag is defined. The
container tag is more readable while the simple tag is nicer for short
variants. When the names "lang:xx" are still to large for you, you
can use the "short" attribute to "<lang:new>"
<lang:new id=en short>
<lang:new id=de short>
when then leads to the defintion of the shortcut variants:
<en>...</en>
<de>...</de>
<en: ...>
<de: ...>
Additionally you always have the
"<lang:area>"..."</lang:area>" container tag
available which provides an alternative way of selecting the language in its
body. It automatically surrounds the data between `"(xx)"' start
tags with the corresponding "LANG_XX" slice.
The following are equal:
<lang:xx: Foo><lang:yy Bar>
<lang:xx>Foo</lang:xx><lang:yy>Bar</lang:yy>
<lang:area>(xx)Foo(yy)Bar</lang:area>
Because these three lines internally get expanded to
[LANG_XX:Foo:][LANG_YY:Bar:]
[LANG_XX:Foo:][LANG_YY:Bar:]
[LANG_XX:Foo:][LANG_YY:Bar:]
There is one additional special tag: "<lang:star:>". This tag
expands its attribute line like the "<lang:xx:>" tags but
multiple times. Actually as much as defined languages exists
("<lang:new>"!). And in each expansion the asterisks (=stars)
in the data gets replaced by the language identifier.
Is is sometimes convenient to use another wildcard, e.g. when defining
navigation bars. The "<lang:set-wildcard>" tag does the job.
The attribute becomes the wildcard used in future substitutions. Without
attribute, the default value is restored. You may specify any regular
expression, and do not forget to escape special characters (the astersisk is
in fact ``\\*'').
<lang:set-wildcard "%">
<lang:star: index.%.html>
<lang:set-wildcard>
There is a more specialized variant named "<lang:star:href:>"
which is similar to "<lang:star:>" but treats its attribute
value as a URL part and tries to check if it already exists. If it doesn't
exist the tag expands the value without the star or an alternative value which
can be appended with ``|alt-value''.
The "<lang:star:slice:>" is another variant to help writing
multi-lingual files quickly. It must come after all occurences of
"<lang:new>" tags.
<lang:star:slice: index.html.*>
The `%BASE' form is recognized (see
wml(1)) and an empty argument is
equivalent to the string `"%BASE.*.html"'. But note that the use of
this tag instead of the WML shebang line prevents WMk from doing its job,
because WMk can not guess output filenames in this case.
For complex multi-lingual documents, you may want to know in which language text
is currently processed. This is achieved with
<lang:current>
which always returns current language (as defined in
"<lang:new>" or an empty string when outside of any language
portion. The macro
<lang:list>
prints the newline separated list of defined languages.
EXAMPLE¶
The following is an example of a webpage "index.wml" with a
multi-lingual header and hyperlink:
#use wml::std::lang
#use wml::std::href
<lang:new id=en short>
<lang:new id=de short>
<lang:star:slice: index.html.*>
<h1><en: Welcome><de: Willkommen></h1>
<href name="The Hyperlink" url="<lang:star: index.*.html>">
<href name="The Hyperlink" url="<lang:star:href: index2.*.html|index2.html>">
When processed via
$ wml index.wml
The following two output files are generated (assuming that
index2.html
and only
index2.de.html exists):
index.html.en:
<h1>Welcome</h1>
<a href="index.en.html">The Hyperlink</a>
<a href="index2.html">The Hyperlink</a>
index.html.de:
<h1>Willkommen</h1>
<a href="index.de.html">The Hyperlink</a>
<a href="index2.de.html">The Hyperlink</a>
AUTHOR¶
Ralf S. Engelschall
rse@engelschall.com
www.engelschall.com
Denis Barbier
barbier@engelschall.com
REQUIRES¶
Internal: P1, P2, P6, P9
External: --
SEE ALSO¶
slice(1)