Now that we've got our User model set up, let's go ahead and add a feature that will allow us to upload profile pictures.

First have a look at the link for active storage.

Let's follow the documentation and set up the active storage

First, add the dependency of image_processing in the Gemfile

gem "image_processing", ">= 1.2"

Run the bundle install in the terminal

bundle install

Install active storage to generate migration for active storage table by running the following in the terminal

bin/rails active_storage:install

we get the tables like below

# This migration comes from active_storage (originally 20170806125915)
class CreateActiveStorageTables < ActiveRecord::Migration[7.0]
  def change
    # Use Active Record's configured type for primary and foreign keys
    primary_key_type, foreign_key_type = primary_and_foreign_key_types

    create_table :active_storage_blobs, id: primary_key_type do |t|
      t.string   :key,          null: false
      t.string   :filename,     null: false
      t.string   :content_type
      t.text     :metadata
      t.string   :service_name, null: false
      t.bigint   :byte_size,    null: false
      t.string   :checksum

      if connection.supports_datetime_with_precision?
        t.datetime :created_at, precision: 6, null: false
      else
        t.datetime :created_at, null: false
      end

      t.index [ :key ], unique: true
    end

    create_table :active_storage_attachments, id: primary_key_type do |t|
      t.string     :name,     null: false
      t.references :record,   null: false, polymorphic: true, index: false, type: foreign_key_type
      t.references :blob,     null: false, type: foreign_key_type

      if connection.supports_datetime_with_precision?
        t.datetime :created_at, precision: 6, null: false
      else
        t.datetime :created_at, null: false
      end

      t.index [ :record_type, :record_id, :name, :blob_id ], name: :index_active_storage_attachments_uniqueness, unique: true
      t.foreign_key :active_storage_blobs, column: :blob_id
    end

    create_table :active_storage_variant_records, id: primary_key_type do |t|
      t.belongs_to :blob, null: false, index: false, type: foreign_key_type
      t.string :variation_digest, null: false

      t.index [ :blob_id, :variation_digest ], name: :index_active_storage_variant_records_uniqueness, unique: true
      t.foreign_key :active_storage_blobs, column: :blob_id
    end
  end

  private
    def primary_and_foreign_key_types
      config = Rails.configuration.generators
      setting = config.options[config.orm][:primary_key_type]
      primary_key_type = setting || :primary_key
      foreign_key_type = setting || :bigint
      [primary_key_type, foreign_key_type]
    end
end

lets run the migration

rails db:migrate

We are setting the service for local and test only which is there by default. We can also add other services like amazon in config/storage.yml

We can tell the active storage which service to use by setting Rails.application.config.active_storage.service on per-environment basis.

For information about more services please visit active storage.

Attaching files to records

• has_one_attached The has_one_attached macro sets up a one-to-one mapping between records and files. Each record can have one file attached to it.

Here, we want a user photo so the User model looks like this

class User < ApplicationRecord
  has_one_attached :photo
end