Rails Assets and URLs

A native Ruflet client runs on a different process or device from Rails. Asset URLs used by that client must therefore be reachable from the client.

Backend URL

Configure the deployed or device-reachable Rails URL in ruflet.yaml:

app:
  name: My Rails App
  backend_url: https://app.example.com

Ruflet::Rails.backend_url resolves an explicit host: first, then the configured backend URL, then the host of the active Ruflet request.

For development on a physical device, use the computer's LAN address instead of localhost:

app:
  backend_url: http://192.168.1.20:3000

Rails asset URLs

Use asset_url to resolve an asset-pipeline path and make it absolute:

image(src: Ruflet::Rails.asset_url("logo.png"), fit: "cover")
image(src: Ruflet::Rails.image_url("brand/header.png"))

image_url is an alias for asset_url.

Ruflet::Rails.asset_url("logo.png", host: "https://app.example.com")

An existing absolute URL or asset-host URL passes through unchanged.

Embed a mounted Ruflet web app

Use ruflet_frame inside an ERB view to embed a mounted Ruflet web frontend:

<%= ruflet_frame "/dashboard", height: 640 %>
<%= ruflet_frame "/showcase", height: "80vh", width: "100%" %>

Relative paths stay same-origin. Numeric dimensions become pixels, string dimensions pass through, and additional HTML attributes are escaped.

The helper is included in Action View automatically.