New localization extension: jQueryMsg - Wikitech-l

17 Aug 2011

I took a little time last week and wrapped Neik K's parserPlus library into
an extension.  It implements a nice framework for grabbing localized message
strings, with limited but very useful PEG-based wikitext parsing, all on the
client-side.  This is code that's been in use in UploadWizard for some time
now, but the extension makes it available to other projects as well.

tl;dr:
1. Enable the extension, it makes two functions available in your JS.
2. string example: $( '.status' ).append( gM( 'mwe-upwiz-file-all-ok' )
);
3. chainable jQuery example: $( '.status' ).msg( 'mwe-upwiz-file-all-ok'
);
4. It does lots more stuff, check the docs.

Why does this exist?  In Neil's own words:

"In the course of writing UploadWizard, I started to rely on MwEmbed's
message library, which had limited wikitext parsing. This was a great help
to internationalization, and the PLURAL support was nice.

"MwEmbed was ultimately not accepted for integration into MediaWiki, so the
ResourceLoader framework was invented to replace that. But we had little or
no support for wikitext-parsed messages. Simple replacements were handled,
but not complicated or nested parsing.

"Michael Dale and NeilK (that's me) wrote another class (MwMessage.js) to
supply the needed features and some advanced ideas like dropping jQuery
nodes right into message strings. But I felt that it was still a bit too
hacky and had some annoying flaws. For every message, you needed to
instantiate another parser. Also, parameters like $1 were replaced before
the message was actually parsed, leading to some unnecessary convolutions
and code repetition for the advanced jQuery-oriented features that Michael
was exploiting heavily."

It's pretty cool.  I can imagine this functionality being pulled into Core
at some point, but for the moment the extension provides a low-impact way
for  the rest of us to take advantage of it.  When it does get incorporated
into core, code changes required in extensions should be very minimal.

Read more: http://www.mediawiki.org/wiki/Extension:JQueryMsg

-Ian