models: Add submission labels

Labels are arbitrary bits of metadata attached to a submission. They can
be used to signify priority, category, or other similar information.
They can also be used to filter patches and identify the ones most
interesting to a given user.

Labels can be associated with a project to ensure that one project can
use a totally different set of labels to another and to, in the future,
allow a project administrator to use their own labels. However, they can
also be global, which is useful for things that would be common across
multiple projects such as "RFC".

Author: stephenfin

patchwork/fixtures/default_labels.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<django-objects version="1.0">
+  <object model="patchwork.label" pk="1">
+    <field name="project" rel="ManyToOneRel" to="patchwork.project"><None></None></field>
+    <field name="name" type="CharField">RFC</field>
+    <field name="description" type="TextField">"RFC" stands for "Request for Comment", which tells maintainers that they should review your patch thoroughly and provide feedback. RFC is typically used when sending feature patches for the first time, or anytime the patch is more than just a simple bug fix.</field>
+    <field name="color" type="PositiveIntegerField">#EDEDED</field>
+  </object>
+</django-objects>

patchwork/migrations/0054_add_patch_labels.py

@@ -0,0 +1,82 @@
+# Generated by Django 6.0.7 on 2026-07-31 21:26
+
+import django.db.models.deletion
+import patchwork.fields
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ('patchwork', '0053_series_ordering_indexes'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='Label',
+            fields=[
+                (
+                    'id',
+                    models.AutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name='ID',
+                    ),
+                ),
+                (
+                    'name',
+                    models.CharField(
+                        help_text='The label value.', max_length=25
+                    ),
+                ),
+                (
+                    'description',
+                    models.TextField(
+                        blank=True,
+                        help_text='A description of what the label is '
+                        'and when it should be applied.',
+                        null=True,
+                    ),
+                ),
+                (
+                    'color',
+                    patchwork.fields.ColorField(
+                        help_text='The color code to use in the UI.'
+                    ),
+                ),
+                (
+                    'project',
+                    models.ForeignKey(
+                        blank=True,
+                        help_text='The project this label is associated with. '
+                        'If unset, this label is global to the instance',
+                        null=True,
+                        on_delete=django.db.models.deletion.CASCADE,
+                        related_name='labels',
+                        related_query_name='label',
+                        to='patchwork.project',
+                    ),
+                ),
+            ],
+            options={
+                'ordering': ['name'],
+                'constraints': [
+                    models.UniqueConstraint(
+                        models.F('project'),
+                        django.db.models.functions.text.Lower('name'),
+                        name='uniq_labels_project_id_name',
+                    ),
+                ],
+            },
+        ),
+        migrations.AddField(
+            model_name='cover',
+            name='labels',
+            field=models.ManyToManyField(to='patchwork.label'),
+        ),
+        migrations.AddField(
+            model_name='patch',
+            name='labels',
+            field=models.ManyToManyField(to='patchwork.label'),
+        ),
+    ]

patchwork/models.py

@@ -15,11 +15,12 @@
 from django.core.validators import validate_unicode_slug
 from django.core.validators import MaxValueValidator
 from django.db import models
+from django.db.models.constraints import UniqueConstraint
 from django.urls import reverse
 from django.utils.functional import cached_property
 from django.utils import timezone as tz_utils
 
-from patchwork.fields import HashField
+from patchwork.fields import HashField, ColorField
 from patchwork.hasher import hash_diff
 
 if settings.ENABLE_REST_API:
@@ -261,6 +262,60 @@ class Meta:
         ordering = ['ordering']
 
 
+class Label(models.Model):
+    """Labels for patches.
+
+    Labels are arbitrary bits of metadata attached to a patch. They can
+    be used to signify priority, category, or other similar information.
+    They can also be used to filter patches and identify the ones most
+    interesting to a given user.
+    """
+
+    project = models.ForeignKey(
+        Project,
+        related_name='labels',
+        related_query_name='label',
+        null=True,
+        blank=True,
+        on_delete=models.CASCADE,
+        help_text='The project this label is associated with. If unset, this '
+        'label is global to the instance',
+    )
+
+    name = models.CharField(max_length=25, help_text='The label value.')
+    description = models.TextField(
+        null=True,
+        blank=True,
+        help_text='A description of what the label is and when it should be '
+        'applied.',
+    )
+    color = ColorField(help_text='The color code to use in the UI.')
+
+    def __str__(self):
+        return self.name
+
+    @staticmethod
+    def get_project_labels(project):
+        result = {}
+        project_labels = Label.objects.filter(
+            models.Q(project=project) | models.Q(project__isnull=True)
+        ).all()
+
+        for label in project_labels:
+            if label.name not in result or label.project is not None:
+                result[label.name] = label
+
+        return list(result.values())
+
+    class Meta:
+        ordering = ['name']
+        constraints = [
+            UniqueConstraint(
+                'project', Lower('name'), name='uniq_labels_project_id_name'
+            )
+        ]
+
+
 class Tag(models.Model):
     name = models.CharField(max_length=20)
     pattern = models.CharField(
@@ -441,6 +496,7 @@ class SubmissionMixin(FilenameMixin, EmailMixin, models.Model):
     # submission metadata
 
     name = models.CharField(max_length=255)
+    labels = models.ManyToManyField(Label)
 
     @cached_property
     def list_archive_url(self):

releasenotes/notes/labels-6d0096c7d8505627.yaml

@@ -0,0 +1,11 @@
+---
+features:
+  - |
+    Add support for patch labels. Labels are a way to organize and prioritize
+    submissions. You can apply labels to patches and cover letters to signify
+    priority, category, or any other marker you wish.
+
+    Labels can be either global or tied to the project they are created in.
+    Labels can have an optional description attached, which will provide a
+    little insight into the purpose of the label. Labels are completely
+    customizable and the labels available will vary by instance.