Add Filter ActiveStorage Blobs To Only Images as a Rails TIL

rails/filter-active-storage-blobs-to-only-images.md

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+# Filter ActiveStorage Blobs To Only Images
+
+If your Rails app is using `ActiveStorage` for both images and ActionMailbox
+emails, then you're going to have a mix of both in the `active_storage_blobs`
+table.
+
+```sql
+> select id, filename, content_type from active_storage_blobs limit 2;
+
+| id | filename           | content_type   |
+|----|--------------------|----------------|
+|  1 | shirt-brothers.jpg | image/jpeg     |
+|  2 | message.eml        | message/rfc822 |
+```
+
+In that case, you are going to want to make sure that any part of your system
+that only cares to deal with images filters down to only blobs where the
+`content_type` is one that you care about.
+
+I expect that there might be a couple different image `content_type` values
+that my system handles, so I filter my `active_storage_blobs` like so:
+
+
+```ruby
+@images =
+  ActiveStorage::Blob
+    .where(content_type: %w[image/jpeg image/png image/gif image/webp])
+    .order(created_at: :desc)
+    .first(10)
+```