ActionView::Helpers::PrototypeHelper::JavaScriptGenerator::GeneratorMethods

JavaScriptGenerator generates blocks of JavaScript code that allow you to change the content and presentation of multiple DOM elements. Use this in your Ajax response bodies, either in a <script> tag or as plain JavaScript sent with a Content-type of "text/javascript".

Create new instances with PrototypeHelper#update_page or with ActionController::Base#render, then call insert_html, replace_html, remove, show, hide, visual_effect, or any other of the built-in methods on the yielded generator in any order you like to modify the content and appearance of the current page.

Example:

  # Generates:
  #     new Insertion.Bottom("list", "<li>Some item</li>");
  #     new Effect.Highlight("list");
  #     ["status-indicator", "cancel-link"].each(Element.hide);
  update_page do |page|
    page.insert_html :bottom, 'list', "<li>#{@item.name}</li>"
    page.visual_effect :highlight, 'list'
    page.hide 'status-indicator', 'cancel-link'
  end

Helper methods can be used in conjunction with JavaScriptGenerator. When a helper method is called inside an update block on the page object, that method will also have access to a page object.

Example:

  module ApplicationHelper
    def update_time
      page.replace_html 'time', Time.now.to_s(:db)
      page.visual_effect :highlight, 'time'
    end
  end

  # Controller action
  def poll
    render(:update) { |page| page.update_time }
  end

Calls to JavaScriptGenerator not matching a helper method below generate a proxy to the JavaScript <a href="/rails/Class">Class</a> named by the method called.

Examples:

  # Generates:
  #     Foo.init();
  update_page do |page|
    page.foo.init
  end

  # Generates:
  #     Event.observe('one', 'click', function () {
  #       $('two').show();
  #     });
  update_page do |page|
    page.event.observe('one', 'click') do |p|
     p[:two].show
    end
  end

You can also use PrototypeHelper#update_page_tag instead of PrototypeHelper#update_page to wrap the generated JavaScript in a <script> tag.