Added blog.Entry.social_media_card field

Author: bmispelon

blog/admin.py

@@ -15,6 +15,7 @@ class EntryAdmin(admin.ModelAdmin):
     list_filter = ("is_active",)
     exclude = ("summary_html", "body_html")
     prepopulated_fields = {"slug": ("headline",)}
+    raw_id_fields = ["social_media_card"]
 
     def formfield_for_dbfield(self, db_field, **kwargs):
         formfield = super().formfield_for_dbfield(db_field, **kwargs)

blog/migrations/0005_entry_social_media_card.py

@@ -0,0 +1,19 @@
+# Generated by Django 6.0.dev20250403184043 on 2025-04-11 07:55
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('blog', '0004_imageupload'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='entry',
+            name='social_media_card',
+            field=models.ForeignKey(blank=True, help_text='For maximum compatibility, the image should be < 5 MB and at least 1200x627 px.', null=True, on_delete=django.db.models.deletion.PROTECT, to='blog.imageupload'),
+        ),
+    ]

blog/models.py

@@ -9,7 +9,7 @@
 from django.utils.cache import _generate_cache_header_key
 from django.utils.formats import date_format
 from django.utils.translation import gettext_lazy as _
-from django_hosts.resolvers import reverse
+from django_hosts.resolvers import get_host, reverse, reverse_host
 from docutils.core import publish_parts
 from markdown import markdown
 from markdown.extensions.toc import TocExtension, slugify as _md_title_slugify
@@ -98,6 +98,21 @@ class ImageUpload(models.Model):
     class Meta:
         ordering = ("-uploaded_on",)
 
+    def __str__(self):
+        return f"({self.uploaded_on.date()}) {self.title}"
+
+    @property
+    def full_url(self):
+        """
+        Return a full URL (scheme + hostname + path) to the image
+        """
+        p = urlparse(self.image.url)
+        if p.netloc:
+            return self.image.url
+        host = get_host()
+        hostname = reverse_host(host)
+        return f"{host.scheme}{hostname}{host.port}{self.image.url}"
+
 
 class Entry(models.Model):
     headline = models.CharField(max_length=200)
@@ -123,6 +138,16 @@ class Entry(models.Model):
     body = models.TextField()
     body_html = models.TextField()
     author = models.CharField(max_length=100)
+    social_media_card = models.ForeignKey(
+        ImageUpload,
+        on_delete=models.PROTECT,
+        blank=True,
+        null=True,
+        help_text=_(
+            "For maximum compatibility, the image should be < 5 MB "
+            "and at least 1200x627 px."
+        ),
+    )
 
     objects = EntryQuerySet.as_manager()
 
@@ -179,7 +204,7 @@ def invalidate_cached_entry(self):
 
     @property
     def opengraph_tags(self):
-        return {
+        tags = {
             "og:type": "article",
             "og:title": self.headline,
             "og:description": _("Posted by {author} on {pub_date}").format(
@@ -195,6 +220,13 @@ def opengraph_tags(self):
             "twitter:creator": "djangoproject",
             "twitter:site": "djangoproject",
         }
+        if card := self.social_media_card:
+            tags |= {
+                "og:image": card.full_url,
+                "og:image:alt": card.alt_text,
+            }
+
+        return tags
 
 
 class EventQuerySet(EntryQuerySet):

blog/tests.py

@@ -2,6 +2,7 @@
 from datetime import date, timedelta
 from io import StringIO
 
+import time_machine
 from django.contrib.auth.models import User
 from django.core.files.base import ContentFile
 from django.test import TestCase
@@ -280,3 +281,19 @@ def test_contentformat_image_tags(self):
                     cf.img(url="/test/image.png", alt_text="TEST"),
                     expected,
                 )
+
+    @time_machine.travel("2005-07-21")
+    def test_full_url(self):
+        i = ImageUpload.objects.create(
+            title="test",
+            alt_text="test",
+            image=ContentFile(b".", name="test.png"),
+        )
+        # Because the storage is persistent between test runs, running this
+        # test twice will trigger a filename clash and the storage will append
+        # a random suffix to the filename, hence the use of assertRegex here.
+        self.assertRegex(
+            i.full_url,
+            r"http://www\.djangoproject\.localhost:8000"
+            r"/m/blog/images/2005/07/test(_\w+)?\.png",
+        )