Re: [PATCH proxmox-i18n v2] add pgettext() and npgettext() support for context-aware translations

["Kefu Chai" <k.chai@proxmox.com>]

On Tue Feb 17, 2026 at 11:45 PM CST, Maximiliano Sandoval wrote:

Hi Maximiliano,

Thanks for the detailed testing and feedback! I've addressed all the
points you raised.

> Kefu Chai <k.chai@proxmox.com> writes:
>
> Thanks for the update. Comments below.
>
>> This commit adds message context (msgctxt) support to the JavaScript
>> [..]
>>  Makefile |  1 +
>>  po2js.pl | 69 ++++++++++++++++++++++++++++++++++++++++++++++++--------
>>  2 files changed, 61 insertions(+), 9 deletions(-)
>>
>> diff --git a/Makefile b/Makefile
>> index 86bd723..3feaee7 100644
>> --- a/Makefile
>> +++ b/Makefile
>> @@ -155,6 +155,7 @@ define potupdate
>>        --package-version="$(shell cd $(2);git rev-parse HEAD)" \
>>        --msgid-bugs-address="<support@proxmox.com>" \
>>        --copyright-holder="Copyright (C) Proxmox Server Solutions GmbH <support@proxmox.com> & the translation contributors." \
>> +      --keyword=npgettext:1c,2,3 \
>
> You were right in your previous reply, however as I mentioned, gettext
> by default has keys for gettext, ngettext, pgettext and npgettext. There
> is no need to add this here.

I investigated this further and found that while this is true for C/C++, it's
not true for JavaScript. The --keyword flag is actually required.

According to the GNU gettext manual [1], the default keywords are
language-specific:

  For C, C++, GCC-source:
    gettext, dgettext:2, dcgettext:2, ngettext:1,2, dngettext:2,3,
    dcngettext:2,3, gettext_noop, pgettext:1c,2, dpgettext:2c,3,
    dcpgettext:2c,3, npgettext:1c,2,3, dnpgettext:2c,3,4, dcnpgettext:2c,3,4

  For JavaScript, TypeScript, TSX:
    _, gettext, dgettext:2, dcgettext:2, ngettext:1,2, dngettext:2,3,
    pgettext:1c,2, dpgettext:2c,3

Notice that npgettext is present in C/C++ defaults but ABSENT from JavaScript.

The xgettext source code confirms this. In gettext-tools/src/x-c.c [2]:

  static void init_keywords () {
    if (default_keywords) {
      x_c_keyword ("gettext");
      x_c_keyword ("dgettext:2");
      x_c_keyword ("dcgettext:2");
      x_c_keyword ("ngettext:1,2");
      x_c_keyword ("dngettext:2,3");
      x_c_keyword ("dcngettext:2,3");
      x_c_keyword ("gettext_noop");
      x_c_keyword ("pgettext:1c,2");
      x_c_keyword ("dpgettext:2c,3");
      x_c_keyword ("dcpgettext:2c,3");
      x_c_keyword ("npgettext:1c,2,3");      /* <- present for C */
      x_c_keyword ("dnpgettext:2c,3,4");
      x_c_keyword ("dcnpgettext:2c,3,4");
      // ...
    }
  }

But in gettext-tools/src/x-javascript.c [3]:

  static void init_keywords () {
    if (default_keywords) {
      x_javascript_keyword ("gettext");
      x_javascript_keyword ("dgettext:2");
      x_javascript_keyword ("dcgettext:2");
      x_javascript_keyword ("ngettext:1,2");
      x_javascript_keyword ("dngettext:2,3");
      x_javascript_keyword ("pgettext:1c,2");
      x_javascript_keyword ("dpgettext:2c,3");
      x_javascript_keyword ("_");
      /* npgettext is NOT here */      /* <- absent for JavaScript */
      default_keywords = false;
    }
  }

The official release notes for gettext 0.18.3 (July 2013) [4] explain
the reason of the difference:


  "JavaScript:
   xgettext now partially supports JavaScript. Since the current
   JavaScript specification (ECMA-262) does not define the standard
   set of formatting methods nor translation functions, the
   implementation supports only a limited set of formatting methods
   and translation functions commonly used in Gjs and other popular
   JavaScript implementations and libraries."

This was a deliberate design decision to include only commonly-used
functions in the JavaScript defaults. The context+plural combination
(npgettext) was apparently not common enough in 2013 to be included.

We can confirm with testing:

  # C: npgettext extracted by default
  $ echo 'npgettext("ctx", "s", "p", n);' > test.c
  $ xgettext test.c -o - | grep msgctxt
  msgctxt "ctx"  # GOOD!

  # JavaScript: npgettext NOT extracted without --keyword
  $ echo 'npgettext("ctx", "s", "p", n);' > test.js
  $ xgettext --language=JavaScript test.js -o - | grep msgctxt
  (empty)  # MISSING!

  # JavaScript WITH --keyword flag
  $ xgettext --language=JavaScript --keyword=npgettext:1c,2,3 test.js -o - | grep msgctxt
  msgctxt "ctx"  # GOOD!

References:

[1] GNU gettext manual - xgettext Invocation (Language-specific default keywords)
    https://www.gnu.org/software/gettext/manual/html_node/xgettext-Invocation.html

[2] gettext source: x-c.c (C language keyword definitions)
    https://github.com/autotools-mirror/gettext/blob/master/gettext-tools/src/x-c.c

[3] gettext source: x-javascript.c (JavaScript language keyword definitions)
    https://github.com/autotools-mirror/gettext/blob/master/gettext-tools/src/x-javascript.c

[4] gettext 0.18.3 Release Notes (July 2013 - JavaScript support added)
    https://git.savannah.gnu.org/gitweb/?p=gettext.git;a=blob;f=NEWS
    Or: https://github.com/autotools-mirror/gettext/blob/master/NEWS

>
>>        --output="$(1)".pot
>>  endef
>>  
>> diff --git a/po2js.pl b/po2js.pl
>> index 316c0bd..4b7b044 100755
>> [..]
>>  
>>  if ($outfile) {
>
>
> I tested this with pve-manager.
>
> - Sprinkled a few uses of pgettext
> - Extracted the strings with make do_update at proxmox-i18n
> - Translated two strings with context
> - Checked that the translated string were visible at the web UI and that
>   each one had the correct translation given its context
>
> To make the above work I had to patch proxmox-biome to accept the
> ngettext and pngettext keywords:
>
> modified   src/biome.json
> @@ -128,7 +128,9 @@
>              "Proxmox",
>              "eslint",
>              "ngettext",
> -            "gettext"
> +            "gettext",
> +            "pgettext",
> +            "npgettext"
>          ]
>      }
>  }

Updated proxmox-biome/src/biome.json to add pgettext and npgettext
to the globals list. Will send a separate patch to the mailing list.

>
> Otherwise `make deb` would fail when building the .debs.
>
> I also had to modify the index.html.tpl to pve-manager to have default
> implementations for these fns, otherwise the UI won't work if there is
> no language selected (which is the default):

Done. Added default implementations to all three locations:
  - pve-manager/www/index.html.tpl
  - proxmox-backup/www/index.hbs
  - pmg-gui/pmg-index.html.tt

Will update them separately, and bump up the submodules in the next
revision of this patch once these patches land.

FWIW, to replicate your testing approach, I performed the following
verification:

1. Added pgettext/npgettext test translation to zh_CN.po, 
2. Generated JavaScript with po2js.pl:
   ./po2js.pl -t pve -v "3.6.6" -o pve-lang-zh_CN-test.js zh_CN.po
3. Verified context-aware translations in generated JavaScript manually.

Also, I built all .deb packages with:

  make deb


>
> modified   www/index.html.tpl
> @@ -27,6 +27,8 @@
>      <script type='text/javascript'>
>          function gettext(message) { return message; }
>          function ngettext(singular, plural, count) { return count === 1 ? singular : plural; }
> +        function pgettext(context, message) { return message; }
> +        function pngettext(context, singular, plural, count) { return count === 1 ? singular : plural; }
>      </script>
>      [% END %]
>      [%- IF debug %]
>
> There are similar files at pmg-gui and proxmox-backup-server that would
> also need updating.