Revamp Membership models to be very simple and do some view/template work for them.

src/membership/admin.py

@@ -1,8 +1,13 @@
 from django.contrib import admin
 
-from . import models
+from .models import Membership, MembershipType
 
 
-@admin.register(models.Membership)
+@admin.register(Membership)
 class MembershipAdmin(admin.ModelAdmin):
     pass
+
+
+@admin.register(MembershipType)
+class MembershipTypeAdmin(admin.ModelAdmin):
+    pass

src/membership/migrations/0001_initial.py

@@ -1,11 +1,9 @@
-# Generated by Django 3.1.7 on 2021-02-27 20:06
+# Generated by Django 3.1.7 on 2021-02-28 21:09
 
-from decimal import Decimal
 from django.conf import settings
 import django.contrib.postgres.fields.ranges
 from django.db import migrations, models
 import django.db.models.deletion
-import djmoney.models.fields
 
 
 class Migration(migrations.Migration):
@@ -18,36 +16,16 @@ class Migration(migrations.Migration):
 
     operations = [
         migrations.CreateModel(
-            name='SubscriptionType',
+            name='MembershipType',
             fields=[
                 ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
                 ('modified', models.DateTimeField(auto_now=True, verbose_name='modified')),
                 ('created', models.DateTimeField(auto_now_add=True, verbose_name='oprettet')),
                 ('name', models.CharField(max_length=64, verbose_name='navn')),
-                ('fee_currency', djmoney.models.fields.CurrencyField(choices=[('DKK', 'DKK')], default='XYZ', editable=False, max_length=3)),
-                ('fee', djmoney.models.fields.MoneyField(decimal_places=2, max_digits=16)),
-                ('fee_vat_currency', djmoney.models.fields.CurrencyField(choices=[('DKK', 'DKK')], default='XYZ', editable=False, max_length=3)),
-                ('fee_vat', djmoney.models.fields.MoneyField(decimal_places=2, default=Decimal('0'), max_digits=16)),
             ],
             options={
-                'verbose_name': 'subscription type',
+                'verbose_name': 'membership type',
-                'verbose_name_plural': 'subscription types',
+                'verbose_name_plural': 'membership types',
-            },
-        ),
-        migrations.CreateModel(
-            name='Subscription',
-            fields=[
-                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
-                ('modified', models.DateTimeField(auto_now=True, verbose_name='modified')),
-                ('created', models.DateTimeField(auto_now_add=True, verbose_name='oprettet')),
-                ('active', models.BooleanField(default=False, help_text='Automatically set by payment system.', verbose_name='aktiv')),
-                ('duration', django.contrib.postgres.fields.ranges.DateTimeRangeField(help_text='The duration this subscription is for. ')),
-                ('subscription_type', models.ForeignKey(on_delete=django.db.models.deletion.PROTECT, related_name='memberships', to='membership.subscriptiontype', verbose_name='subscription type')),
-                ('user', models.ForeignKey(on_delete=django.db.models.deletion.PROTECT, to=settings.AUTH_USER_MODEL)),
-            ],
-            options={
-                'verbose_name': 'subscription',
-                'verbose_name_plural': 'subscriptions',
             },
         ),
         migrations.CreateModel(
@@ -56,7 +34,9 @@ class Migration(migrations.Migration):
                 ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
                 ('modified', models.DateTimeField(auto_now=True, verbose_name='modified')),
                 ('created', models.DateTimeField(auto_now_add=True, verbose_name='oprettet')),
-                ('user', models.OneToOneField(on_delete=django.db.models.deletion.PROTECT, to=settings.AUTH_USER_MODEL)),
+                ('period', django.contrib.postgres.fields.ranges.DateTimeRangeField(help_text='The duration this subscription is for. ')),
+                ('membership_type', models.ForeignKey(on_delete=django.db.models.deletion.PROTECT, related_name='memberships', to='membership.membershiptype', verbose_name='subscription type')),
+                ('user', models.ForeignKey(on_delete=django.db.models.deletion.PROTECT, to=settings.AUTH_USER_MODEL)),
             ],
             options={
                 'verbose_name': 'membership',

src/membership/models.py

@@ -1,7 +1,9 @@
+from typing import Optional
+
 from django.contrib.postgres.fields import DateTimeRangeField
 from django.db import models
+from django.utils import timezone
 from django.utils.translation import gettext as _
-from djmoney.models.fields import MoneyField
 
 
 class CreatedModifiedAbstract(models.Model):
@@ -13,65 +15,67 @@ class CreatedModifiedAbstract(models.Model):
         abstract = True
 
 
+
 class Membership(CreatedModifiedAbstract):
     """
-    A user remains a member of an organization even though the subscription is
+    Tracks that a user has membership of a given type for a given period.
-    unpaid or renewed. This just changes the status/permissions etc. of the
-    membership, thus we need to track subscription creation, expiry, renewals
-    etc. and ensure that the membership is modified accordingly.
     """
 
-    user = models.OneToOneField("auth.User", on_delete=models.PROTECT)
+    class QuerySet(models.QuerySet):
 
-    def __str__(self):
+        def for_user(self, user):
-        return _(f"{self.user.get_full_name()} is a member")
+            return self.filter(user=user)
+
+        def _current(self):
+            return self.filter(period__contains=timezone.now())
+
+        def current(self) -> Optional["Membership"]:
+            try:
+                return self._current().get()
+            except self.model.DoesNotExist:
+                return None
+
+        def previous(self):
+            # A naïve way to get previous by just excluding the current. This
+            # means that there must be some protection against "future"
+            # memberships.
+            return self.all().difference(self._current())
+
+    objects = QuerySet.as_manager()
 
     class Meta:
         verbose_name = _("membership")
         verbose_name_plural = _("memberships")
 
+    user = models.ForeignKey("auth.User", on_delete=models.PROTECT)
 
-class SubscriptionType(CreatedModifiedAbstract):
+    membership_type = models.ForeignKey(
-    """
+        "membership.MembershipType",
-    Properties of subscriptions are stored here. Should of course not be edited
-    after subscriptions are created.
-    """
-
-    name = models.CharField(verbose_name=_("name"), max_length=64)
-
-    fee = MoneyField(max_digits=16, decimal_places=2)
-
-    fee_vat = MoneyField(max_digits=16, decimal_places=2, default=0)
-
-    class Meta:
-        verbose_name = _("subscription type")
-        verbose_name_plural = _("subscription types")
-
-
-class Subscription(CreatedModifiedAbstract):
-    """
-    To not confuse other types of subscriptions, one can be a *subscribed*
-    member, meaning that they are paying etc.
-
-    A subscription does not track payment, this is done in the accounting app.
-    """
-
-    subscription_type = models.ForeignKey(
-        SubscriptionType,
         related_name="memberships",
         verbose_name=_("subscription type"),
         on_delete=models.PROTECT,
     )
-    user = models.ForeignKey("auth.User", on_delete=models.PROTECT)
 
-    active = models.BooleanField(
+    period = DateTimeRangeField(help_text=_("The duration this subscription is for. "))
-        default=False,
-        verbose_name=_("active"),
-        help_text=_("Automatically set by payment system."),
-    )
 
-    duration = DateTimeRangeField(help_text=_("The duration this subscription is for. "))
+    def __str__(self):
+        return f"{self.user} - {self.period}"
+
+
+class MembershipType(CreatedModifiedAbstract):
+    """
+    Models membership types. Currently only a name, but will in the future
+    possibly contain more information like fees.
+    """
 
     class Meta:
-        verbose_name = _("subscription")
+        verbose_name = _("membership type")
-        verbose_name_plural = _("subscriptions")
+        verbose_name_plural = _("membership types")
+
+    name = models.CharField(verbose_name=_("name"), max_length=64)
+
+    def __str__(self):
+        return self.name
+
+
+

src/membership/templates/membership_overview.html

@@ -0,0 +1,22 @@
+{% extends "base.html" %}
+{% load i18n %}
+
+{% block content %}
+
+    {% if not current_membership %}
+        <p>{% trans "You do not have an active membership!" %}</p>
+
+        <p>{% trans "You can become a member by depositing the membership fee to our bank account." %}</p>
+
+        <ul>
+            <li>Reg. 8401 (Merkur)</li>
+            <li>Kontonr. 1016866</li>
+            <li>Tekst på overførslen: Your email</li>
+        </ul>
+    {% else %}
+        <p>{% trans "You are a member!" %}</p>
+
+        <p>{% trans "Period" %}: {{ current_membership.period.lower|date:"SHORT_DATE_FORMAT" }} to {{ current_membership.period.upper|date:"SHORT_DATE_FORMAT" }}</p>
+        <p>{% trans "Type" %}: {{ current_membership.membership_type }}</p>
+    {% endif %}
+    {% endblock %}

src/membership/views.py

@@ -0,0 +1,18 @@
+from django.contrib.auth.decorators import login_required
+from django.shortcuts import render
+
+from .models import Membership
+
+
+@login_required
+def membership_overview(request):
+    memberships = Membership.objects.for_user(request.user)
+    current_membership = memberships.current()
+    previous_memberships = memberships.previous()
+
+    context = dict(
+        current_membership=current_membership,
+        previous_memberships=previous_memberships,
+    )
+
+    return render(request, "membership_overview.html", context)

src/project/templates/base.html

@@ -166,7 +166,8 @@
 
                 <ul class="nav flex-column">
                     <li class="nav-item">
-                        <a class="nav-link" href="#">
+                        <a class="nav-link {% active_path "membership-overview" "active" %}"
+                           aria-current="page" href="{% url "membership-overview" %}">
                             {% trans "Overview" %}
                         </a>
                     </li>

src/project/urls.py

@@ -7,10 +7,12 @@ from django.urls import path
 import debug_toolbar
 
 from .views import index, services_overview
+from membership.views import membership_overview
 
 urlpatterns = [
     path("", login_required(index), name="index"),
     path("services/", login_required(services_overview), name="services-overview"),
+    path("membership/", membership_overview, name="membership-overview"),
     path('accounts/', include('allauth.urls')),
     path("admin/", admin.site.urls),
     path("__debug__/", include(debug_toolbar.urls)),