Detect type of SlugRelatedField with readonly=True (#83)

* Added test for #82 - readonly SlugRelatedField not showing format uuid
* Added ArticleGroup model
* Added example of SlugRelatedField to a uuid field with and without readonly
* Check remote_field.model in get_related_model

Closes #82.

docs/changelog.rst

@@ -9,6 +9,7 @@ Changelog
 *Release date: TODO*
 
 - **IMPROVED:** ``serializers.HiddenField`` are now hidden (:issue:`78`)
+- **IMPROVED:** format is now detected for ``SlugRelatedField`` with ``read_only=True``  (:issue:`82`)
 
 *********
 **1.4.7**

src/drf_yasg/inspectors/field.py

@@ -161,7 +161,11 @@ def get_related_model(model, source):
     :return: related model or ``None``
     """
     try:
-        return getattr(model, source).rel.related_model
+        descriptor = getattr(model, source)
+        try:
+            return descriptor.rel.related_model
+        except Exception:
+            return descriptor.field.remote_field.model
     except Exception:  # pragma: no cover
         return None
 

testproj/articles/migrations/0003_auto_20180310_0142.py

@@ -0,0 +1,36 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.11 on 2018-03-10 01:42
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+import django.db.models.deletion
+import uuid
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('articles', '0002_article_article_type'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='ArticleGroup',
+            fields=[
+                ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('uuid', models.UUIDField(default=uuid.uuid4, editable=False, unique=True)),
+                ('title', models.CharField(help_text='title model help_text', max_length=255, unique=True)),
+                ('slug', models.SlugField(blank=True, help_text='slug model help_text', unique=True)),
+            ],
+        ),
+        migrations.AddField(
+            model_name='article',
+            name='group',
+            field=models.ForeignKey(blank=True, default=None, on_delete=django.db.models.deletion.PROTECT, related_name='articles_as_main', to='articles.ArticleGroup'),
+        ),
+        migrations.AddField(
+            model_name='article',
+            name='original_group',
+            field=models.ForeignKey(blank=True, default=None, on_delete=django.db.models.deletion.PROTECT, related_name='articles_as_original', to='articles.ArticleGroup'),
+        ),
+    ]

testproj/articles/models.py

@@ -1,3 +1,5 @@
+import uuid
+
 from django.db import models
 
 
@@ -14,3 +16,14 @@ class Article(models.Model):
     )
 
     cover = models.ImageField(upload_to='article/original/', blank=True)
+    group = models.ForeignKey('ArticleGroup', related_name='articles_as_main', blank=True, default=None,
+                              on_delete=models.PROTECT)
+    original_group = models.ForeignKey('ArticleGroup', related_name='articles_as_original', blank=True, default=None,
+                                       on_delete=models.PROTECT)
+
+
+class ArticleGroup(models.Model):
+    uuid = models.UUIDField(default=uuid.uuid4, editable=False, unique=True)
+
+    title = models.CharField(help_text="title model help_text", max_length=255, blank=False, unique=True)
+    slug = models.SlugField(help_text="slug model help_text", unique=True, blank=True)

testproj/articles/serializers.py

@@ -1,7 +1,7 @@
 from django.utils.translation import ugettext_lazy as _
 from rest_framework import serializers
 
-from articles.models import Article
+from articles.models import Article, ArticleGroup
 
 
 class ArticleSerializer(serializers.ModelSerializer):
@@ -12,11 +12,13 @@ class ArticleSerializer(serializers.ModelSerializer):
     )
     uuid = serializers.UUIDField(help_text="should articles have UUIDs?", read_only=True)
     cover_name = serializers.FileField(use_url=False, source='cover', read_only=True)
+    group = serializers.SlugRelatedField(slug_field='uuid', queryset=ArticleGroup.objects.all())
+    original_group = serializers.SlugRelatedField(slug_field='uuid', read_only=True)
 
     class Meta:
         model = Article
         fields = ('title', 'author', 'body', 'slug', 'date_created', 'date_modified',
-                  'references', 'uuid', 'cover', 'cover_name', 'article_type')
+                  'references', 'uuid', 'cover', 'cover_name', 'article_type', 'group', 'original_group', )
         read_only_fields = ('date_created', 'date_modified',
                             'references', 'uuid', 'cover_name')
         lookup_field = 'slug'

tests/reference.yaml

@@ -542,6 +542,7 @@ definitions:
     required:
       - title
       - body
+      - group
     type: object
     properties:
       title:
@@ -601,6 +602,13 @@ definitions:
           - 3
           - 7
           - 8
+      group:
+        type: string
+        format: uuid
+      original_group:
+        type: string
+        format: uuid
+        readOnly: true
   Project:
     required:
       - projectName