Initial work to support many-to-many fields.

Author: adamghill

django_unicorn/serializer.py

@@ -73,6 +73,20 @@ def _get_model_dict(model: Model) -> dict:
     model_json = model_json.get("fields")
     model_json["pk"] = model_pk
 
+    for field in model._meta.get_fields():
+        if field.is_relation and field.many_to_many:
+            related_name = field.related_name or f"{field.name}_set"
+            pks = []
+
+            try:
+                related_descriptor = getattr(model, related_name)
+                pks = list(related_descriptor.values_list("pk", flat=True))
+            except ValueError:
+                # ValueError is throuwn when the model doesn't have an id already set
+                pass
+
+            model_json[related_name] = pks
+
     return model_json
 
 

django_unicorn/views/action_parsers/utils.py

@@ -64,10 +64,20 @@ class TestView(UnicornView):
                     is_relation_field = False
 
                     # Set the id property for ForeignKeys
-                    # TODO: Move this to utility function
+                    # TODO: Move some of this to utility function
                     if hasattr(component_or_field, "_meta"):
-                        for field in component_or_field._meta.fields:
-                            if field.name == property_name_part:
+                        for field in component_or_field._meta.get_fields():
+                            if field.is_relation and field.many_to_many:
+                                related_name = field.related_name or f"{field.name}_set"
+
+                                if related_name == property_name_part:
+                                    related_descriptor = getattr(
+                                        component_or_field, related_name
+                                    )
+                                    related_descriptor.set(property_value)
+                                    is_relation_field = True
+                                    break
+                            elif field.name == property_name_part:
                                 if field.is_relation:
                                     setattr(
                                         component_or_field,

django_unicorn/views/utils.py

@@ -34,7 +34,12 @@ def set_property_from_data(
     Sets properties on the component based on passed-in data.
     """
 
-    if not hasattr(component_or_field, name):
+    try:
+        if not hasattr(component_or_field, name):
+            return
+    except ValueError:
+        # Treat ValueError the same as a missing field because trying to access a many-to-many
+        # field before the model's pk will throw this exception
         return
 
     field = getattr(component_or_field, name)

example/coffee/migrations/0004_origin_taste.py

@@ -0,0 +1,29 @@
+# Generated by Django 3.1.7 on 2021-04-11 18:00
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('coffee', '0003_auto_20210128_0140'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='Taste',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('name', models.CharField(max_length=255)),
+                ('flavor', models.ManyToManyField(to='coffee.Flavor')),
+            ],
+        ),
+        migrations.CreateModel(
+            name='Origin',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('name', models.CharField(max_length=255)),
+                ('flavor', models.ManyToManyField(related_name='origins', to='coffee.Flavor')),
+            ],
+        ),
+    ]

example/coffee/models.py

@@ -19,3 +19,13 @@ class Flavor(models.Model):
 
     def __str__(self):
         return self.name
+
+
+class Taste(models.Model):
+    name = models.CharField(max_length=255)
+    flavor = models.ManyToManyField(Flavor)
+
+
+class Origin(models.Model):
+    name = models.CharField(max_length=255)
+    flavor = models.ManyToManyField(Flavor, related_name="origins")

example/unicorn/components/models.py

@@ -1,5 +1,5 @@
 from django_unicorn.components import QuerySetType, UnicornView
-from example.coffee.models import Flavor
+from example.coffee.models import Flavor, Taste
 
 
 class ModelsView(UnicornView):
@@ -28,5 +28,11 @@ def delete(self, flavor_to_delete: Flavor):
     def available_flavors(self):
         return Flavor.objects.all()
 
+    def available_tastes(self):
+        return Taste.objects.all()
+
     class Meta:
-        javascript_exclude = ("available_flavors",)
+        javascript_exclude = (
+            "available_flavors",
+            "available_tastes",
+        )

example/unicorn/templates/unicorn/models.html

@@ -54,6 +54,20 @@ <h4>{{ flavor.pk }}</h4>
                 {{ flavor.parent.name }}
                 <br />
 
+                <label>Taste</label>
+                <select unicorn:model="flavors.{{ forloop.counter0 }}.taste_set" multiple>
+                    {% for available_taste in available_tastes %}
+                    <option value="{{ available_taste.pk }}">{{ available_taste.name }}</option>
+                    {% endfor %}
+                </select>
+
+                <ul>
+                {% for taste in flavor.taste_set.all %}
+                    <li>{{ taste.name }}</li>
+                {% endfor %}
+                </ul>
+                <br />
+
                 <button unicorn:click="save({{ forloop.counter0 }})">save(flavor_idx)</button>
                 <button unicorn:click="delete({{ flavor.pk }})">delete(flavor.pk)</button>
             </div>

tests/serializer/test_dumps.py

@@ -80,6 +80,8 @@ def test_model_with_datetime(db):
             "time": None,
             "duration": None,
             "pk": None,
+            "taste_set": [],
+            "origins": [],
         }
     }
 
@@ -104,6 +106,8 @@ def test_model_with_datetime_as_string(db):
             "time": None,
             "duration": None,
             "pk": None,
+            "taste_set": [],
+            "origins": [],
         }
     }
 
@@ -128,6 +132,8 @@ def test_model_with_time_as_string(db):
             "time": time,
             "duration": None,
             "pk": None,
+            "taste_set": [],
+            "origins": [],
         }
     }
 
@@ -152,6 +158,8 @@ def test_model_with_duration_as_string(db):
             "time": None,
             "duration": "-1 19:00:00",
             "pk": None,
+            "taste_set": [],
+            "origins": [],
         }
     }
 
@@ -204,6 +212,8 @@ def test_dumps_queryset(db):
                 "time": None,
                 "duration": None,
                 "pk": 1,
+                "taste_set": [],
+                "origins": [],
             },
             {
                 "name": "name2",
@@ -217,6 +227,8 @@ def test_dumps_queryset(db):
                 "time": None,
                 "duration": None,
                 "pk": 2,
+                "taste_set": [],
+                "origins": [],
             },
         ]
     }
@@ -241,6 +253,8 @@ def test_get_model_dict():
         "datetime": None,
         "time": None,
         "duration": None,
+        "taste_set": [],
+        "origins": [],
     }
 
     assert expected == actual

tests/serializer/test_model_value.py

@@ -1,5 +1,7 @@
 from django.db import models
 
+import pytest
+
 from django_unicorn.components import ModelValueMixin
 from django_unicorn.serializer import model_value
 from example.coffee.models import Flavor
@@ -20,6 +22,8 @@ def test_model_value_all_fields():
         "pk": None,
         "time": None,
         "uuid": str(flavor.uuid),
+        "taste_set": [],
+        "origins": [],
     }
 
     actual = model_value(flavor)
@@ -36,6 +40,7 @@ def test_model_value_one_field():
     assert expected == actual
 
 
+@pytest.mark.django_db
 def test_model_value_multiple_field():
     expected = {
         "pk": 77,

tests/templatetags/test_unicorn_render.py

@@ -2,6 +2,8 @@
 
 from django.template.base import Token, TokenType
 
+import pytest
+
 from django_unicorn.components import UnicornView
 from django_unicorn.templatetags.unicorn import unicorn
 from django_unicorn.utils import generate_checksum
@@ -163,6 +165,7 @@ def to_json(self):
     )
 
 
+@pytest.mark.django_db
 def test_unicorn_render_parent_with_model_pk(settings):
     settings.DEBUG = True
     token = Token(