refactor(apps/tasks): refactor some stuff

apps/tasks/admin.py

@@ -3,8 +3,13 @@
 from django.contrib.admin import ModelAdmin, register
 from django.contrib.postgres.forms import SimpleArrayField
 from django.core.files.uploadedfile import InMemoryUploadedFile
-from django.forms import CharField, IntegerField, ModelForm, Textarea
-from django.forms.fields import FileField
+from django.forms import (
+    CharField,
+    FileField,
+    IntegerField,
+    ModelForm,
+    Textarea,
+)
 from django.http import HttpRequest
 from django.utils.translation import gettext_lazy as _
 
@@ -20,7 +25,7 @@
 
 class TaskModelForm(TaskModelFormBase):
     description = CharField(widget=Textarea(attrs={"rows": 14, "cols": 80}))
-    constraints = SimpleArrayField(CharField(max_length=256))
+    constraints = SimpleArrayField(CharField(max_length=256), required=False)
     score = IntegerField(min_value=0, required=False)
 
     memory_limit = IntegerField(
@@ -63,6 +68,9 @@ def save_model(
         form: TaskModelForm,
         change: bool,
     ) -> None:
+        if change and len(request.FILES) == 0:
+            return super().save_model(request, obj, form, change)
+
         # request.FILES does not cast to the correct type so we need to
         # cast it manually, otherwise Mypy will complain.
         input_file = cast(InMemoryUploadedFile, request.FILES["input_file"])

server/settings/base.py

@@ -70,6 +70,7 @@
     "django.contrib.messages",
     "django.contrib.staticfiles",
     "django.contrib.humanize",
+    "django.contrib.postgres",
 ]
 
 THIRD_PARTY_APPS = [

templates/tasks/detail.html

@@ -38,18 +38,17 @@ <h1>
 <h4>Description</h4>
 <p>{{ task.description }}</p>
 
+<hr>
+
 <h4>Constraints</h4>
 <ul>
-  {% if task.constraints %}
-    {% for constraint in task.constraints %}
-      <li>
-        {{ constraint }}
-      </li>
-    {% endfor %}
-  {% else %}
-    <li> None </li>
-  {% endif %}
+  {% for constraint in task.constraints %}
+    <li>{{ constraint }}</li>
+  {% empty %}
+    <li>None</li>
+  {% endfor %}
 </ul>
+
 <hr>
 
 <form method="post">