# Show/hide buttons throughout the admin

You might want to hide some buttons and not show them to your users. That's pretty handy using the Authorization feature. You control the display of those buttons using the policy methods.

  • Show button -> show? method
  • Edit button -> edit? method
  • Delete button -> destroy? method
  • Upload attachments button -> upload_attachments? method
  • Download attachments button -> download_attachments? method
  • Delete attachments button -> delete_attachments? method
  • Attach button -> attach_#{RESOURCE_PLURL_NAME}? (eg: attach_posts?) method
  • Detach button -> detach_#{RESOURCE_PLURL_NAME}? (eg: detach_posts?) method

# Why don't regular url helpers work as expected?

When writing rails code somewhere in Avo domain you might want to use your regular url helpers like below:


field :partner_home, as: :text, as_html: true do |model, *args|
  link_to 'Partner', partner_home_url(model)

This will not work because Avo will execute that code inside itself, a Rails engine. So per the Rails documentation (opens new window) you have to preprend the helper with main_app for it to work. Rails need to know for which engine should it search the route. So the above query becomes this 👇


field :partner_home, as: :text, as_html: true do |model, *args|
  link_to 'Partner', main_app.partner_home_url(model)

# I want to give access to different kind of users to different resources.

You can do that using Pundit scopes and the Authorization feature. You create a policy for that resource and set the condition on the index? method. More on that on the authorization page and Pundit's docs (opens new window).

Authorization is a Pro feature for Avo. Please let us know if you need a trial key to test it out.

# How can I set a homepage for the admin section

You can do that using the home_path configuration. You just set config.home_path = "/avo/resources/posts" (or whatever path you'd like) in the Avo initializer and you're all set up. The user will be redirected to that path when navigating to /avo.


# config/initializers/avo.rb

Avo.configure do |config|
  config.root_path = '/avo'
  config.license = 'pro'
  config.license_key = ENV['AVO_LICENSE_KEY']
  config.id_links_to_resource = true
  config.home_path = '/avo/resources/posts'
  config.set_context do
      foo: 'bar',
      user: current_user,
      params: request.params,

# I want to have 2 different resources maped to the same model with different type

This depends on your setup:

  1. If you have Rails STI (opens new window), then it will work. Avo knows how to handle STI models. So you'll have two models and an Avo resource for each one. That will render two resources in your admin panel's sidebar.
  2. You don't have Rails STI but something custom. Then the response is it depends. Because something custom is... custom, we offer a few mechanisms to get over that.

If you have one model User, then you'll have one Avo resource UserResource. Then you can customize different things based your requirements. Like if for instance you want to show only some types of users on the Index view, you can use custom query scopes (opens new window) to hide specific types (if that's what you want to do). Same if you want to show/hide fields (opens new window) based on the type of resource or type of user.

All in all we're confident you'll have the necessary instruments you need to build your admin.

# Try a pre-release version

From time to time we push pre-release versions of the gem for you to try out before pushing to the main branch. To test them out you need to specify the exact version in your Gemfile.

Let's say you want to try out 1.19.1.pre.1. You need to specify it like below 👇

# Gemfile

# ... other gems

gem 'avo', '1.19.1.pre.1'

# The authorization features are not working

If you're having trouble with the authorization feature, make sure you have the following enabled:

  • you are on a Pro license
  • you have set the current_user_method
  • you have reset the rails server after the above settings
  • you have the pundit policy on the appropriate model

# Add custom methods/get custom data

You might want to be able to send custom data to some of the blocks you use (default block, computed fields, field formatters, etc.). You can use the context block. The block is evaluated in the ApplicationController so it has access to the params and other common controller methods. More on that here.