Active Storage Example App

A sample Rails application using activestorage for file storage and upload.

Running the app

Run the migrations, and create a .env file like this:

ACCESS_KEY_ID=youraccesskeyid
SECRET_ACCESS_KEY=yoursecretaccesskey
REGION=yourregion
BUCKET=yourbucket

Generating the migration

Active Storage uses two database tables: one to store the filename, content type etc, and the other to join the attachment to the model that 'owns' it, for example User.

Running rails active_storage:install when you set up a new project generates the migrations for these tables.

Service configuration

Different service types are configured in config/storage.yml. Examples of possible service types are:

• Local Disk
• Amazon S3dw
• Microsoft Azure Storage
• Google Cloud Storage

You then set which service should be used in each environment. For example, in development, config.active_storage.service = :local.

Model relations

Attachments are defined as model relations, see the User model in this example. You can use has_one_attached and has_many_attached and they do exactly what you might imagine.

Direct uploads

There is support for direct uploads out of the box, just set direct_upload: true on the form field. Uploads begin on form submission.

There are multiple javascript events you can then tap in to (start, initialize, progress, end etc) to make cool looking uploads.

Download links

You can create a download link using the view helper rails_blob_path, setting the disposition. The redirection has an HTTP expiration of 5 mins.