I ended up creating a new method hasRole
in my User
Class :
public function hasRole($role)
{
return in_array($role, $this->getRoles());
}
Then, in a template, I use:
{% if app.user.hasRole('ROLE_VIEW_GEOLOC_DATA') %}
{# do something #}
{% endif %}
EDIT:
As @JonnyS said, it may be possible that roles must start with ROLE_
to work with is_granted
Symfony's function. Didn't tested.