class ActiveAdmin::BatchAction

=> You can pass a hash of options to `:form` that will be rendered as form input fields for the user to fill out.
BatchAction.new(:flag, form: {foo: :text, bar: :checkbox}) { |selection, inputs| }

=> You can pass a custom confirmation message through `:confirm`
BatchAction.new(:flag, confirm: "Are you sure?") { |selection| }

=> You can pass `true` to `:confirm` to use the default confirm message.
BatchAction.new :flag, confirm: true

=> You can provide an `:if` proc to choose when the batch action should be displayed
BatchAction.new(:flag, if: proc{ can? :flag, AdminUser }) { |selection| }

=> You can create batch actions with a title instead of a Symbol
BatchAction.new("Perform Long Operation on") { |selection| }

=> Will create an action that uses a block to process the request (which receives one paramater of the selected objects)
BatchAction.new(:flag) { |selection| redirect_to collection_path, notice: "#{selection.length} users flagged" }

=> Will create an action that appears in the action list popover
BatchAction.new :flag

Examples:

Create a Batch Action

def initialize(sym, title, options = {}, &block)
  @sym, @title, @options, @block, @confirm = sym, title, options, block, options[:confirm]
  @block ||= proc {}
end