Tiny po2json-compatible gettext with variable substitution
npm install gettext-pythonic 
Tiny po2json-compatible gettext with variable substitution.
This is a simplification of some of the ideas found at localeplanet.com.
``shell`
bower install gettext-pythonic --save
You can then integrate bower_components/gettext-pythonic/gettext-pythonic.min.js to your build as needed. (The non-minified version is a CommonJS module, not suitable for direct browser use.) This was generated using browserify --standalone and is thus safe as-is or with various module systems. Stand-alone example:
`html`
...
`shell`
npm install gettext-pythonic --save
In Node.JS or if you're using Browserify to bundle CommonJS modules together for client-side use, you can choose whichever name you'd like, although keep in mind that following conventions tends to work best. In JavaScript, the most common names to avoid conflicts with Underscore.JS are gettext()/ngettext() and short forms __()/n_().
`js`
var gettext = require('gettext-pythonic');
var __ = gettext.gettext;
var n_ = gettext.ngettext;
...
gettext.load(require('locales/fr.json'));
console.log(__("This sentence is in English."));
If all you need is a quick and dirty 1:1 translation with substitutions but no plural forms, you don't need to use xgettext and po2json: a simple object where each key is a source string and each value is the translated version, will also work (including variable substitution).
Example:
`json`
var myLanguage = {
"English original": "Translated equivalent",
"Another one": "..."
};
Or if you want plural forms, but still no xgettext, use arrays with one
element offset (that's just how PO files are structured):
`json`
var myLanguage = {
"There is one result": [
null,
"Il y a %{count} résultat",
"Il y a %{count} résultats"
]
};
Maintain your English PO template the standard way, with our friendly function aliases:
`sh`
xgettext -L JavaScript -k -k__ -kgettext -kn_:1,2 -kngettext:1,2 --force-po -o locales/messages.pot ...files...
Use tools such as poedit to maintain the translations, such as a locales/fr.po for example, then use po2json to generate the JSON equivalent of each non-English PO file:
`sh`
po2json locales/fr.po htdocs/locale_fr.json --fuzzy
It is then up to you to feed the resulting JSON data to gettext.load() at run-time.
(a.k.a. __(...))
The supplied englishString is looked up in the current language and substituted if found. The optional envObject is used for variable substitution (see below).
(a.k.a. n_(...))
Like its C counterpart, ngettext() expects a singular and a plural string, followed by the number on which to decide which version to return. (Other languages may have more than two variants, but gettext conveniently requires that English be used for keys.) The optional envObject is used for variable substitution (see below).
Loads the supplied translation object (either a basic set of pairs or an output of po2json).
Instead of going for a sprintf() means of substituting variables, which couldn't be reordered, I implemented "pythonic string formatting" with an added percentage to help translators, which makes both of the following possible:
`js``
__("Talking about %{0} and %{1}.", [somevar, othervar]);
__("Talking about %{foo} and %{bar}.", {'foo': somevar, 'bar': othervar});
Since the whole point is to be independent of argument order, I recommend always using the named variation.
Copyright (c) 2016 Stephane Lavergne
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