msgctxt

Set a template's default gettext message context:

{% msgctxt "shop: checkout" %}
<h2>{_ Order _}</h2>
{% button text=_"Continue" %}

Declare it once, before output or blocks. An extends or overrules tag may precede it. The context must be a literal string and is extracted as msgctxt in the POT file. Use stable semantic labels, rather than template filenames.

The default applies to {_ ... _}, _"...", and {% trans ... %} messages. Override it with tag#with_msgctxt or an explicit msgctxt argument on tag#trans_ext. Included and inherited templates use their own declarations.

For each language, lookup tries the contextual translation and then the contextless translation. It then tries fallback languages, finally using the English source. An empty context string is distinct from no message context.

Adding a context creates new catalog identities. Existing contextless translations remain usable through fallback while contextual entries are translated.

A module can supply the default for all its templates using an attribute on its module Erlang file, alongside mod_title and mod_description:

-mod_msgctxt("shop: checkout").

The selected template file's owning module supplies this default, including when templates override another module's templates. Includes and inherited templates each use their own module's default. A template's msgctxt declaration overrides the module default; scopes and explicit trans arguments override it in turn. An explicitly empty context remains an override.

POT extraction uses the same default. The attribute applies to templates; Erlang translation calls and macros continue to take their message context explicitly. Modules without the attribute retain their existing behavior.