Modeling and admin for attachment support

todo/admin.py

@@ -1,18 +1,25 @@
 from django.contrib import admin
-from todo.models import Task, TaskList, Comment
+
+from todo.models import Attachment, Comment, Task, TaskList
 
 
 class TaskAdmin(admin.ModelAdmin):
     list_display = ("title", "task_list", "completed", "priority", "due_date")
     list_filter = ("task_list",)
     ordering = ("priority",)
-    search_fields = ("name",)
+    search_fields = ("title",)
 
 
 class CommentAdmin(admin.ModelAdmin):
     list_display = ("author", "date", "snippet")
 
 
+class AttachmentAdmin(admin.ModelAdmin):
+    list_display = ("task", "added_by", "timestamp", "file")
+    autocomplete_fields = ["added_by", "task"]
+
+
 admin.site.register(TaskList)
 admin.site.register(Comment, CommentAdmin)
 admin.site.register(Task, TaskAdmin)
+admin.site.register(Attachment, AttachmentAdmin)

todo/migrations/0010_attachment.py

@@ -0,0 +1,28 @@
+# Generated by Django 2.2 on 2019-04-06 16:28
+
+import datetime
+from django.conf import settings
+from django.db import migrations, models
+import django.db.models.deletion
+import todo.models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+        ('todo', '0009_priority_optional'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='Attachment',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('timestamp', models.DateTimeField(default=datetime.datetime.now)),
+                ('file', models.FileField(max_length=255, upload_to=todo.models.get_attachment_upload_dir)),
+                ('added_by', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to=settings.AUTH_USER_MODEL)),
+                ('task', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, to='todo.Task')),
+            ],
+        ),
+    ]

todo/models.py

@@ -10,6 +10,13 @@ from django.urls import reverse
 from django.utils import timezone
 
 
+def get_attachment_upload_dir(instance, filename):
+    """Determine upload dir for task attachment files.
+    """
+
+    return "/".join(["tasks", "attachments", str(instance.task.id), filename])
+
+
 class LockedAtomicTransaction(Atomic):
     """
     modified from https://stackoverflow.com/a/41831049
@@ -156,3 +163,19 @@ class Comment(models.Model):
 
     def __str__(self):
         return self.snippet
+
+
+class Attachment(models.Model):
+    """
+    Defines a generic file attachment for use in M2M relation with Task.
+    """
+
+    task = models.ForeignKey(Task, on_delete=models.CASCADE)
+    added_by = models.ForeignKey(
+        settings.AUTH_USER_MODEL, on_delete=models.CASCADE
+    )
+    timestamp = models.DateTimeField(default=datetime.datetime.now)
+    file = models.FileField(upload_to=get_attachment_upload_dir, max_length=255)
+
+    def __str__(self):
+        return f"{self.task.id} - {self.file.name}"