Are you using Active Storage to handle file uploading to the cloud (maybe AWS) and you want to know how to attach an uploaded file to an email?… But you are not familiar with the Active Storage and Action Mailer APIs?
I answered this question on reddit some days ago =)… Here is how you can do it…
You need to download the file and assign as and attachment, something like this…
attachments[photo.filename.to_s] = photo.download
Here the context of the example…
class Product < ApplicationRecord
has_one_attached :photo
end
class PhotoMailer < ApplicationMailer
default from: "default@example.com"
def new_photo_email
photo = params[:product].photo
attachments[photo.filename.to_s] = photo.download
mail(to: "one@example.com", subject: "Nueva photo")
end
end
class PhotoMailerPreview < ActionMailer::Preview
def new_photo_email
PhotoMailer.with(product: Product.first).new_photo_email
end
end
Here the reference from the rails guides https://edgeguides.rubyonrails.org/activestorageoverview.html#downloading-files
If you are not familiar with Action Mailer and you are reading the docs, maybe is not that clear what you need to do. Here is what I understand.
On the Action Mailer docs you can see…
attachments['filename.jpg'] = File.read('/path/to/filename.jpg')
Inside the [] you need to put the name that you want for the attachment and you need to assign the content of the file. Like this:
attachments[filename] = file_content
In the example from the docs, File.read returns the content of the file.
Now, in the ActiveStorage docs says that you can “Use the attachment’s download method to read a blob’s binary data into memory”, and they use this example:
binary = user.avatar.download
That’s why I propose you to use download. Apparently download will return the content of the file wherever the file is stored.
Here I try to share knowledge and fixes to common problems and struggles for ruby on rails developers, like How to fetch the latest-N-of-each record or How to test that an specific mail was sent or a Capybara cheatsheet. You can see more examples on Most recent posts or all posts.