ActiveAdmin Dynamic Fields

gem version gem downloads linters specs

An Active Admin plugin to add dynamic behaviors to some fields.


  • set conditional checks on fields
  • trigger actions on target elements
  • inline field editing
  • create links to load some content in a dialog

The easiest way to show how this plugin works is looking the examples below.

Please :star: if you like it.


First, add the gem to your ActiveAdmin project: gem 'activeadmin_dynamic_fields' (and execute bundle)

If you installed Active Admin without Webpacker support:

  • add at the end of your ActiveAdmin javascripts (app/assets/javascripts/active_admin.js):
//= require activeadmin/dynamic_fields

Otherwise with Webpacker:

  • Execute in your project root:
yarn add blocknotes/activeadmin_dynamic_fields
  • Add to your app/javascript/packs/active_admin.js:


Options are passed to fields using input_html parameter as data attributes.


  • data-if: check a condition, values:
    • checked: check if a checkbox is checked (ex. "data-if": "checked")
    • not_checked: check if a checkbox is not checked (equivalent to "data-if": "!checked")
    • blank: check if a field is blank
    • not_blank: check if a field is not blank
    • changed: check if the value of an input is changed (dirty)
  • data-eq: check if a field has a specific value (ex. "data-eq": "42" or "data-eq": "!5")
  • data-not: check if a field has not a specific value (equivalent to "data-eq": "!something")
  • data-match: check if a field match a regexp
  • data-mismatch: check if a field doesn't match a regexp (ex. "data-mismatch": "^\d+$")
  • data-function: check the return value of a custom function (ex. "data-function": "my_check")


  • data-then: action to trigger (alias data-action), values:
    • hide: hides elements (ex. "data-then": "hide", "data-target": ".errors")
    • slide: hides elements (using sliding)
    • fade: hides elements (using fading)
    • addClass: adds classes (ex. "data-then": "addClass red")
    • addStyle: adds some styles (ex. "data-then": "addStyle color: #fb1; font-size: 12px")
    • setText: set the text of an element (ex. "data-then": "setText A sample text")
    • setValue: set the value of an input element (ex. "data-then": "setValue A sample value")
    • callback: call a function (with arguments: data-args) (ex. "data-then": "callback a_fun")
  • data-else: action to trigger when the condition check is not true
  • data-args: arguments passed to the callback function


  • data-target: target css selector (from parent fieldset, look for the closest match)
  • data-gtarget: target css selector globally

A check condition or a custom check function are required. A trigger action is required too, unless you are using a custom function (in that case it is optional).


Dynamic fields examples

  • A checkbox that hides other fields if is checked (ex. model Article):
form do |f|
  f.inputs 'Article' do
    f.input :published, input_html: { data: { if: 'checked', then: 'hide', target: '.grp1' } }
    f.input :online_date, wrapper_html: { class: 'grp1' }
    f.input :draft_notes, wrapper_html: { class: 'grp1' }
  • Add 3 classes (first, second, third) if a checkbox is not checked, else add "forth" class:
data = { if: 'not_checked', then: 'addClass first second third', target: '.grp1', else: 'addClass forth' }
f.input :published, input_html: { data: data }
  • Set another field value if a string field is blank:
f.input :title, input_html: { data: { if: 'blank', then: 'setValue 10', target: '#article_position' } }
  • Use a custom function for conditional check (title_not_empty() must be available on global scope) (with alternative syntax for data attributes):
attrs = { 'data-function': 'title_empty', 'data-then': 'slide', 'data-target': '#article_description_input' }
f.input :title, input_html: attrs
function title_empty(el) {
  return ($('#article_title').val().trim() === '');
  • Call a callback function as action:
data = { if: 'checked', then: 'callback set_title', args: '["Unpublished !"]' }
f.input :published, input_html: { data: data }
function set_title(args) {
  if($('#article_title').val().trim() === '') {
  • Custom function without action:
collection = [['Cat 1', 'cat1'], ['Cat 2', 'cat2'], ['Cat 3', 'cat3']]
f2.input :category, as: :select, collection: collection, input_html: { 'data-function': 'on_change_category' }
function on_change_category(el) {
  var target = el.closest('fieldset').find('.pub');
  target.prop('checked', (el.val() == 'cat2');

Inline editing examples

  • Prepare a custom member action to save data, an update helper function is available (third parameter is optional, allow to filter using strong parameters):
member_action :save, method: [:post] do
  render ActiveAdmin::DynamicFields.update(resource, params)
  # render ActiveAdmin::DynamicFields.update(resource, params, [:published])
  # render ActiveAdmin::DynamicFields.update(resource, params, Article::permit_params)
  • In index config:
# Edit a string:
column :title do |row|
  div row.title, ActiveAdmin::DynamicFields.edit_string(:title, save_admin_article_path(
# Edit a boolean:
column :published do |row|
  status_tag row.published, ActiveAdmin::DynamicFields.edit_boolean(:published, save_admin_article_path(, row.published)
# Edit a select ([''] allow to have a blank value):
column :author do |row|
  select ActiveAdmin::DynamicFields.edit_select(:author_id, save_admin_article_path( do
    options_for_select([''] + Author.pluck(:name, :id), row.author_id)
  • In show config (inside attributes_table block): rb row :title do |row| div row.title, ActiveAdmin::DynamicFields.edit_string(:title, save_admin_article_path( end

Dialog example

Example with 2 models: Author and Article

Prepare the content dialog - in Active Admin Author config:

ActiveAdmin.register Author do
  # ...
  member_action :dialog do
    record = resource
    context = do
      dl do
        %i[name age created_at].each do |field|
          dt "#{Author.human_attribute_name(field)}:"
          dd record[field]
    render plain: context
  # ...

Add a link to show the dialog - in Active Admin Article config:

ActiveAdmin.register Article do
  # ...
  show do |object|
    attributes_table do
      # ...
      row :author do
        link_to, dialog_admin_author_path(, title:, 'data-df-dialog': true, 'data-df-icon': true
  # ...

The link url is loaded via AJAX before opening the dialog.

Do you like it? Star it!

If you use this component just star it. A developer is more motivated to improve a project when there is some interest. My other Active Admin components.

Or consider offering me a coffee, it's a small thing but it is greatly appreciated: about me.


  • Mattia Roccoberton: author
  • The good guys that opened issues and pull requests from time to time


The gem is available as open-source under the terms of the MIT.