[How to] Use UUIDs

In order to use the public_activity gem with tables using UUIDs, you'll need to modify the *_create_activities.rb migration file, before running your migrations.

Assuming you want to use UUIDs for the activities table, and are using UUID's for your trackable, owner, and recipient tables, a migration like below should work:

class CreateActivities < (ActiveRecord.version.release() < Gem::Version.new('5.2.0') ? ActiveRecord::Migration : ActiveRecord::Migration[5.2])
  def self.up
    create_table :activities, id: :uuid, default: 'gen_random_uuid()' do |t|
      t.belongs_to :trackable, polymorphic: true, type: :uuid
      t.belongs_to :owner, polymorphic: true, type: :uuid
      t.string  :key
      t.text    :parameters
      t.belongs_to :recipient, polymorphic: true, type: :uuid

      t.timestamps
    end

    add_index :activities, [:trackable_id, :trackable_type]
    add_index :activities, [:owner_id, :owner_type]
    add_index :activities, [:recipient_id, :recipient_type]
  end

  def self.down
    drop_table :activities
  end
end