More about .mo

xili-language multilingual plugin, since his creation five year ago, is based on two main things:

  1. the language of post (and custom post) is defined by the custom taxonomy “language”.
  2. the ‘live’ translation of terms is mainly based on .mo file of current theme (like translation in a localized website) of the current language. The plugin choose the right language according the current language assigned to the single displayed post, the home page or a list of posts.

Case of a standalone theme (w/o parent)

With a current theme with textdomain twentyfourteen (without child), for a french context, the file fr_FR.mo is loaded. (and if created by xili-dictionary or by hand with poEdit, the local-fr_FR.mo).
If the files are not found in a sub-folder of the theme, if, available in subfolder wp-content/languages/themes, the files twentyfourteen-fr_FR.mo and twentyfourteen-local-fr_FR.mo are loaded.
Be aware about that:
if a term or sentence (msgid) and his translation (msgstr) are in the fr_FR.mo and in the local-fr_FR.mo, the translation of local-fr_FR.mo has priority. It is a good thing if you are not satisfied by the translation delivered by the theme’s author!
local-xx_YY.mo currently contains translations of terms et sentences from the website itself (title, date format, categories,…).

Case of child and parent themes:

By default, only the .mo files availables in child theme are loaded.
To help translation strategy and versioning, it is now possible to use also files from parent theme languages folder. xili-language is able the define how will be done the merging between child and parent files.
As in above case, a local file is loaded from the current (here child) theme and has full priority.
For the other files (child and parent), you can define the priority, child or parent… By example, if you don’t want to modify the parent .mo files, so define child files as a priority.

The form is inside the screen under the 4th tab of xili-language settings.

merging .mo files option
merging .mo files option