Active Storage Demo - full files

_item.html.erb

<div id="<%= dom_id item %>">
  <p class="my-5">
    <strong class="block font-medium mb-1">Name:</strong>
    <%= item.name %>
  </p>

  <p class="my-5">
    <strong class="block font-medium mb-1">Contents:</strong>
    <% if item.contents.attached? %>
      <% if item.contents.content_type.start_with? 'image/' %>
        <img src=<%= item.contents.url %> alt="<%= item.contents.filename %>">
      <% elsif item.contents.content_type.start_with? 'audio/' %>
        <audio controls>
          <source src=<%= item.contents.url %> type=<%= item.contents.content_type %>>
        </audio>
      <% elsif item.contents.content_type.start_with? 'video/' %>
        <video controls>
          <source src=<%= item.contents.url %> type=<%= item.contents.content_type %>>
        </audio>
      <% else %>
        <%= link_to item.contents.filename, item.contents %>
      <% end %>
    <% end %>
  </p>

</div>

items_controller.rb

class ItemsController < ApplicationController
  before_action :set_item, only: %i[ show edit update destroy ]
  include ActiveStorage::SetCurrent

  # GET /items or /items.json
  def index
    @items = Item.all
  end

  # GET /items/1 or /items/1.json
  def show
  end

  # GET /items/new
  def new
    @item = Item.new
  end

  # GET /items/1/edit
  def edit
  end

  # POST /items or /items.json
  def create
    @item = Item.new(item_params)

    respond_to do |format|
      if @item.save
        format.html { redirect_to item_url(@item), notice: "Item was successfully created." }
        format.json { render :show, status: :created, location: @item }
      else
        format.html { render :new, status: :unprocessable_entity }
        format.json { render json: @item.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /items/1 or /items/1.json
  def update
    respond_to do |format|
      if @item.update(item_params)
        format.html { redirect_to item_url(@item), notice: "Item was successfully updated." }
        format.json { render :show, status: :ok, location: @item }
      else
        format.html { render :edit, status: :unprocessable_entity }
        format.json { render json: @item.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /items/1 or /items/1.json
  def destroy
    @item.destroy!

    respond_to do |format|
      format.html { redirect_to items_url, notice: "Item was successfully destroyed." }
      format.json { head :no_content }
    end
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_item
      @item = Item.find(params[:id])
    end

    # Only allow a list of trusted parameters through.
    def item_params
      params.require(:item).permit(:name, :contents)
    end
end

routes.rb

Rails.application.routes.draw do
  resources :items
  # Define your application routes per the DSL in https://guides.rubyonrails.org/routing.html

  # Reveal health status on /up that returns 200 if the app boots with no exceptions, otherwise 500.
  # Can be used by load balancers and uptime monitors to verify that the app is live.
  get "up" => "rails/health#show", as: :rails_health_check

  # Defines the root path route ("/")
  root "items#index"
end