Add way for dashboard widgets to add custom CSS/JS files which will be added in the html head

aleksis/core/models.py

 from datetime import date
-from typing import Optional
+from typing import Optional, Iterable, Union
 
 from django.contrib.auth import get_user_model
 from django.contrib.auth.models import User
 from django.db import models
+from django.db.models import QuerySet
+from django.forms.widgets import Media
 from django.utils.translation import ugettext_lazy as _
 from image_cropping import ImageCropField, ImageRatioField
 from phonenumber_field.modelfields import PhoneNumberField
@@ -280,8 +282,13 @@ class DashboardWidget(PolymorphicModel):
 
     If your widget does not add any database fields, you should mark it as a proxy model.
 
+    You can provide a Media meta class with custom JS and CSS files which will be added to html head.
+    For further information on media definition see https://docs.djangoproject.com/en/3.0/topics/forms/media/
+
     Example::
-    
+
+      from django.forms.widgets import Media
+
       from aleksis.core.models import DashboardWidget
 
       class MyWidget(DhasboardWIdget):
@@ -293,9 +300,25 @@ class DashboardWidget(PolymorphicModel):
 
           class Meta:
               proxy = True
+
+          media = Media(css={
+                  'all': ('pretty.css',)
+              },
+              js=('animations.js', 'actions.js')
+          )
     """
 
+    @staticmethod
+    def get_media(widgets: Union[QuerySet, Iterable]):
+        """ Return all media required to render the selected widgets. """
+
+        media = Media()
+        for widget in widgets:
+            media = media + widget.media
+        return media
+
     template = None
+    media = Media()
 
     title = models.CharField(max_length=150, verbose_name=_("Widget Title"))
     active = models.BooleanField(blank=True, verbose_name=_("Activate Widget"))

aleksis/core/templates/core/index.html

@@ -3,6 +3,10 @@
 
 {% block browser_title %}{% blocktrans %}Home{% endblocktrans %}{% endblock %}
 
+{% block extra_head %}
+  {{ media }}
+{% endblock %}
+
 {% block content %}
   <p class="flow-text">{% blocktrans %}AlekSIS (School Information System){% endblocktrans %}</p>
 

aleksis/core/views.py

@@ -33,7 +33,11 @@ def index(request: HttpRequest) -> HttpResponse:
     context["notifications"] = notifications
     context["unread_notifications"] = unread_notifications
 
-    context["widgets"] = DashboardWidget.objects.filter(active=True)
+    widgets = DashboardWidget.objects.filter(active=True)
+    media = DashboardWidget.get_media(widgets)
+
+    context["widgets"] = widgets
+    context["media"] = media
 
     return render(request, "core/index.html", context)