How to use the weblate.utils.messages.error function in weblate

def rate_wrap(request, *args, **kwargs):
            if request.method == 'POST' and not check_rate_limit(scope, request):
                # Rotate session token
                rotate_token(request)
                # Logout user
                do_logout = request.user.is_authenticated
                if do_logout:
                    logout(request)
                messages.error(
                    request,
                    render_to_string(
                        'ratelimit.html', {'do_logout': do_logout}
                    )
                )
                return redirect('login')
            return function(request, *args, **kwargs)
        return rate_wrap

def mail_admins_contact(request, subject, message, context, sender, to):
    """Send a message to the admins, as defined by the ADMINS setting."""
    LOGGER.info('contact form from %s', sender)
    if not to and settings.ADMINS:
        to = [a[1] for a in settings.ADMINS]
    elif not settings.ADMINS:
        messages.error(request, _('Message could not be sent to administrator!'))
        LOGGER.error('ADMINS not configured, can not send message!')
        return

    mail = EmailMultiAlternatives(
        '{0}{1}'.format(settings.EMAIL_SUBJECT_PREFIX, subject % context),
        '{}\n{}'.format(
            message % context,
            TEMPLATE_FOOTER.format(
                address=get_ip_address(request),
                agent=get_user_agent(request),
                username=request.user.username,
            ),
        ),
        to=to,
        headers={'Reply-To': sender},
    )

# Log error
                if self.id:
                    Change.objects.create(
                        component=self,
                        action=action_failed,
                        target=error,
                        user=request.user if request else None,
                        details={"error": error, "status": status},
                    )
                    self.add_alert("MergeFailure", error=error)

                # Reset repo back
                method_func(abort=True)

                # Tell user (if there is any)
                messages.error(request, error_msg % force_text(self))

                return False

            if self.id:
                Change.objects.create(
                    component=self,
                    action=action,
                    user=request.user if request else None,
                )

                # Run post update hook, this should be done with repo lock held
                # to avoid posssible race with another update
                vcs_post_update.send(
                    sender=self.__class__, component=self, previous_head=previous_head
                )
                self.delete_alert("MergeFailure")

def show_language(request, lang):
    try:
        obj = Language.objects.get(code=lang)
    except Language.DoesNotExist:
        obj = Language.objects.fuzzy_get(lang)
        if isinstance(obj, Language):
            return redirect(obj)
        raise Http404('No Language matches the given query.')

    if request.method == 'POST' and request.user.has_perm('language.edit'):
        if obj.translation_set.exists():
            messages.error(
                request, _('Remove all translations using this language first.')
            )
        else:
            obj.delete()
            messages.success(request, _('Language %s removed.') % obj)
            return redirect('languages')

    last_changes = Change.objects.last_changes(request.user).filter(
        translation__language=obj
    )[:10]
    projects = request.user.allowed_projects
    dicts = projects.filter(dictionary__language=obj).distinct()
    projects = projects.filter(component__translation__language=obj).distinct()

    for project in projects:
        project.language_stats = project.stats.get_single_language_stats(obj)

def state_change(request, project, component=None, lang=None):
    obj, unit_set, context = parse_url(request, project, component, lang)

    if not request.user.has_perm('translation.auto', obj):
        raise PermissionDenied()

    form = BulkStateForm(request.user, obj, request.POST)

    if not form.is_valid():
        messages.error(request, _('Failed to process form!'))
        show_form_errors(request, form)
        return redirect(obj)

    matching = unit_set.filter_type(
        form.cleaned_data['type'],
    ).exclude(
        state=STATE_EMPTY
    )

    updated = 0
    with transaction.atomic():
        for unit in matching.select_for_update():
            if not request.user.has_perm('unit.edit', unit):
                continue
            unit.translate(
                request.user,

def auth_fail(request, message):
    messages.error(request, message)
    return redirect(reverse('login'))

def execute_locked(request, obj, message, call, *args, **kwargs):
    """Helper function to catch possible lock exception."""
    try:
        result = call(*args, **kwargs)
        # With False the call is supposed to show errors on its own
        if result is None or result:
            messages.success(request, message)
    except Timeout as error:
        messages.error(
            request,
            _('Failed to lock the repository, another operation is in progress.')
        )
        report_error(error, request)

    return redirect_param(obj, '#repository')

def change_project(request, project):
    obj = get_project(request, project)

    if not request.user.has_perm('project.edit', obj):
        raise Http404()

    if request.method == 'POST':
        settings_form = ProjectSettingsForm(
            request, request.POST, instance=obj
        )
        if settings_form.is_valid():
            settings_form.save()
            messages.success(request, _('Settings saved'))
            return redirect('settings', project=obj.slug)
        else:
            messages.error(
                request,
                _('Invalid settings, please check the form for errors!')
            )
    else:
        settings_form = ProjectSettingsForm(request, instance=obj)

    return render(
        request,
        'project-settings.html',
        {
            'object': obj,
            'settings_form': settings_form,
        }