lemoncurry/wellknowns/views/manifest.py

from django.conf import settings
from django.http import JsonResponse
from django.urls import reverse
from favicon.models import FaviconImg
from lemoncurry import utils
from lemoncurry.theme import color
from urllib.parse import urljoin
from textwrap import shorten


def manifest(request):
    base = utils.origin(request)
    name = settings.LEMONCURRY_SITE_NAME
    start_url = reverse('home:index') + '?utm_source=homescreen'

    app = {
        'name': name,
        'short_name': shorten(name, width=20, placeholder=''),

        'display': 'browser',
        'start_url': urljoin(base, start_url),

        'background_color': color(0),
        'theme_color': color(2),
    }

    rels = ('shortcut icon', 'apple-touch-icon')
    icons = FaviconImg.objects.filter(
        faviconFK__isFavicon=True,
        rel__in=rels,
    ).order_by('size')
    app['icons'] = [{
        'type': 'image/png',
        'sizes': '{0}x{0}'.format(icon.size),
        'src': urljoin(base, icon.faviconImage.url),
    } for icon in icons]

    return JsonResponse(app, content_type='application/manifest+json')