Manually switch _locale in symfony 4 - php

Question

I'm absolutely stuck in getting a solution to manually switch the _locale variable in Symfony 4.
I followed these steps, but now I have absolutely no idea how to make a simple switch button in the nav section. I also took a look a this question, but this seems to be an older Symfony version..
Can anyone please help me climb out of this dark hole and explain to me how I can integrate a simple _locale switch button, or at least point me in the right direction?

Answer 1

The answer is slightly different from this answer which is not applicable in Symfony 4. Start with editing the services.yaml file in the config directory.
{# project/config/services.yaml}
# ...
parameters:
# ...
app_locales: [nl_NL, en_EN]
twig:
# ...
globals:
locales: %app_locales%
# ...
Then add a template to integrate the switch button somewhere in your base template.
{# project/templates/_locale_switcher.html.twig #}
{% set route = app.request.attributes.get('_route') %}
{% set route_params = app.request.attributes.get('_route_params') %}
{% set params = route_params|merge(app.request.query.all) %}
{# You may want to not print a flag/link for current view, the "if" here let
you handle it #}
{% for locale in locales if locale != app.request.locale %}
<li>
<a href="{{ path(route, params|merge({ _locale: locale })) }}">
<img src="{{ asset('img/flags/' ~ locale ~ '.jpg') }}" alt="{{
locale }}">
</a>
</li>
{% endfor %}
And finally integrate this brandnew template in your base template.
{# project/templates/base.html.twig #}
{% include '_locale_switcher.html.twig' %}
EDIT for Symfony 4.3.4+
As per the answer of Charles beneath, the locales value in services.yaml file should be inserted with quotes to avoid an unvalid YAML error:
{# project/config/services.yaml}
# ...
parameters:
# ...
app_locales: [nl_NL, en_EN]
twig:
# ...
globals:
locales: "%app_locales%"
# ...

Answer 2

As of latest Symfony (5.3.9), I strongly suggest one follows the documentation:
https://symfony.com/doc/current/the-fast-track/en/28-intl.html
Towards the end, do a bit of tweaking to generate a nice dropdown menu correctly based on your available languages:
<ul class="navbar-nav me-auto mb-2 mb-md-0">
<li class="nav-item dropdown">
<a class="nav-link dropdown-toggle" href="#" role="button" data-bs-toggle="dropdown" aria-expanded="false" id="locales">
<i class="fa fa-globe" aria-hidden="true"></i>
{{ app.request.locale|locale_name(app.request.locale)|u.title }}
</a>
<ul class="dropdown-menu" aria-labelledby="locales">
{% for locale in locales|split('|') %}
<li>
<a {% if app.request.locale == locale %}
class="dropdown-item active"
{% else %}
class="dropdown-item"
{% endif %}
href="{{ path(app.request.get('_route', 'app_index'), app.request.get('_route_params', [])|merge({_locale: locale})) }}">
{{ locale|locale_name(locale)|u.title }}
</a>
</li>
{% endfor %}
</ul>
</li>
</ul>
PS: The above is using Bootstrap 5.

Answer 3

Here is what works for me on latest symfony 4 version
services.yaml:
parameters:
locale: 'en'
app_locales: en|fr
twig:
globals:
locales: '%app_locales%'
locale template:
{# project/templates/_locale_switcher.html.twig #}
{% set route = app.request.attributes.get('_route') %}
{% set route_params = app.request.attributes.get('_route_params') %}
{% set params = route_params|merge(app.request.query.all) %}
{# You may want to not print a flag/link for current view, the "if" here let
you handle it #}
{% for locale in locales|split('|') %}
{% if locale != app.request.locale %}
<li>
<a href="{{ path(route, params|merge({ _locale: locale })) }}">
<img src="{{ asset('img/flags/' ~ locale ~ '.jpg') }}" alt="{{ locale }}">
</a>
</li>
{% endif %}
{% endfor %}