Files API

Per-option reference for the :files field. For setup and worked examples, see the Files guide.

Options are passed to the field declaration in an Avo resource, such as app/avo/resources/project.rb:

field :documents, as: :files

These options are specific to multiple attachments. See Common field options for the options shared by all fields.

Upload input

-> accept

The file input's HTML accept attribute. It accepts MIME types, file extensions, and comma-separated combinations as described in the HTML specification.

field :documents, as: :files, accept: "image/*,application/pdf"

• Type: String or nil
• Default: nil (no file-type filter)
• Validation: Not validated by Avo; passed to the file input.

WARNING

accept filters the browser's file picker; it does not enforce attachment content types on the server.

-> direct_upload

Enables Active Storage direct uploads for the multiple-file input. Requires a configured Active Storage direct-upload service.

field :documents, as: :files, direct_upload: true

• Type: Boolean
• Default: false

Attachment layout

-> view_type

The initial attachment layout on show and edit pages. A valid view_type request parameter takes precedence over this setting.

field :documents, as: :files, view_type: :list

Value	Behavior
:grid	Thumbnail tiles with previews for images, audio, and video.
:list	File rows with filenames, sizes, and attachment controls.

• Type: Symbol
• Default: :grid
• Values: :grid, :list
• Validation: No declaration-time validation. An unsupported layout can raise NameError when the attachment viewer resolves its component.

-> hide_view_type_switcher

Hides the grid/list switcher above the attachments. This does not prevent a valid view_type request parameter from selecting a layout.

field :documents, as: :files, hide_view_type_switcher: true

• Type: Boolean or nil
• Default: nil (switcher visible)

-> display_filename

Controls filename captions beneath grid previews and in the lightbox. List rows always display their filenames.

field :documents, as: :files, display_filename: false

• Type: Boolean
• Default: true (also used when explicitly set to nil)

Image preview

-> lightbox

Enables the in-page image lightbox on the show page for representable image attachments. Edit-page thumbnails are not lightbox triggers. Audio, video, and documents retain their existing players and controls; the original-file link in the lightbox respects download authorization.

field :documents, as: :files, lightbox: false

• Type: Boolean
• Default: true (also used when explicitly set to nil)