ActiveStorage File Attachment Validation

Question

Is there a way to validate attachments with ActiveStorage? For example, if I want to validate the content type or the file size?

Something like Paperclip\'s approach wou

Answer 1

ActiveStorage doesn't support validations right now. According to https://github.com/rails/rails/issues/31656.

---

Update:

Rails 6 will support ActiveStorage validations.

https://github.com/rails/rails/commit/e8682c5bf051517b0b265e446aa1a7eccfd47bf7

Uploaded files assigned to a record are persisted to storage when the record
is saved instead of immediately.
In Rails 5.2, the following causes an uploaded file in `params[:avatar]` to
be stored:
```ruby
@user.avatar = params[:avatar]
```
In Rails 6, the uploaded file is stored when `@user` is successfully saved.