Julian Maurice authored Mar 29, 2020 and joubu committed Nov 06, 2020

misc/translator/translate was doing three different things:
- extract translatable strings
- create or update PO files
- install translated templates

This patch separates responsibilities by moving the string extraction
code into several 'xgettext-like' scripts and adds gulp tasks to
automate string extraction and PO files update

This has several benefits:

- gulp runs tasks in parallel, so it's a lot faster (updating all PO
  files is at least 10 times faster with my 4-cores CPU)

- there is no need for $KOHA_CONF to be defined
  LangInstaller.pm relied on $KOHA_CONF to get the different paths
  needed. I'm not sure why, since string extraction and PO update should
  work on source files, not installed files

- string extraction code can be more easily tested

This patch also brings a couple of fixes and improvements:

- TT string extraction (strings wrapped in [% t(...) %]) was done with
  Template::Parser and PPI, which was extremely slow, and had some
  problems (see bug 24797).
  This is now done with Locale::XGettext::TT2 (new dependency) which is
  a lot faster, and fixes bug 24797

- Fix header in 4 PO files

For backward compatibility, 'create' and 'update' commands of
misc/translator/translate can still be used and will execute the
corresponding gulp task

Test plan:
1. Run `yarn install` and install Locale::XGettext::TT2
2. Run `gulp po:update`
3. Verify the contents of updated PO files
4. Run `cd misc/translator && ./translate install <lang>`
5. Verify that all (templates, sysprefs, xslt, installer files) is
   correctly translated
6. Run `gulp po:create --lang <lang>` and verify that it created all PO
   files for that language
7. Run `prove t/misc/translator`

Signed-off-by: Bernardo Gonzalez Kriegel <bgkriegel@gmail.com>
Need to install yarn & gulp, no errors

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>