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|inde.html>">
When processed via
$ wml index.wml
The following two output files are generated (assuming that inde.html
and only index2.de.html exists):
index.html.en:
<h1>Welcome</h1>
<a href="index.en.html">The Hyperlink</a>
<a href="inde.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)