# Custom fields

Avo ships with 20+ fields out of the box. They are well polished and ready to be used with your admins.

When you need a field that isn't provided by default, Avo makes it easy to add it.

# Generate a new field

Every new field comes with three view components (opens new window), edit (which is also used in the new view), and show and index. There's also a Field configuration file.

bin/rails generate avo:field progress_bar generates the files for you.

▶ bin/rails generate avo:field progress_bar
      create  app/components/avo/fields/progress_bar_field
      create  app/components/avo/fields/progress_bar_field/edit_component.html.erb
      create  app/components/avo/fields/progress_bar_field/edit_component.rb
      create  app/components/avo/fields/progress_bar_field/index_component.html.erb
      create  app/components/avo/fields/progress_bar_field/index_component.rb
      create  app/components/avo/fields/progress_bar_field/show_component.html.erb
      create  app/components/avo/fields/progress_bar_field/show_component.rb
      create  app/avo/fields/progress_bar_field.rb

The ProgressBarField file is what registers the field in your admin.

class ProgressBarField < Avo::Fields::BaseField
  def initialize(name, **args, &block)
    super(name, **args, &block)
  end
end

Now you can use your field like so:






 


# app/avo/resources/progress_bar_field.rb
class ProjectResource < Avo::BaseResource
  self.title = :name

  field :id, as: :id, link_to_resource: true
  field :progress, as: :progress_bar
end
Progress custom field

The generated view components are basic text fields for now.

# app/components/avo/fields/progress_bar_field/edit_component.html.erb
<%= edit_field_wrapper field: @field, index: @index, form: @form, resource: @resource, displayed_in_modal: @displayed_in_modal do %>
  <%= @form.text_field @field.id,
    class: helpers.input_classes('w-full', has_error: @field.model_errors.include?(@field.id)),
    placeholder: @field.placeholder,
    disabled: @field.readonly %>
<% end %>

# app/components/avo/fields/progress_bar_field/index_component.html.erb
<%= index_field_wrapper field: @field do %>
  <%= @field.value %>
<% end %>

# app/components/avo/fields/progress_bar_field/show_component.html.erb
<%= show_field_wrapper field: @field, index: @index do %>
  <%= @field.value %>
<% end %>

You can customize them and add as much or as little content as needed. More on customization below.

# Field options

This file is where you may add field-specific options.



 
 
 
 




 
 
 
 



# app/avo/fields/progress_bar_field.rb
class ProgressBarField < Avo::Fields::BaseField
 attr_reader :max
 attr_reader :step
 attr_reader :display_value
 attr_reader :value_suffix

 def initialize(name, **args, &block)
   super(name, **args, &block)

   @max = 100
   @step = 1
   @display_value = false
   @value_suffix = nil
 end
end

The field specific options can come from the field declaration as well.











 
 
 
 








 


# app/avo/fields/progress_bar_field.rb
class ProgressBarField < Avo::Fields::BaseField
  attr_reader :max
  attr_reader :step
  attr_reader :display_value
  attr_reader :value_suffix

  def initialize(name, **args, &block)
    super(name, **args, &block)

    @max = args[:max] || 100
    @step = args[:step] || 1
    @display_value = args[:display_value] || false
    @value_suffix = args[:value_suffix] || nil
  end
end

# app/avo/resources/progress_bar_field.rb
class ProjectResource < Avo::BaseResource
  self.title = :name

  field :id, as: :id, link_to_resource: true
  field :progress, as: :progress_bar, step: 10, display_value: true, value_suffix: "%"
end

# Field visibility

If you need to hide the field in some view you can use the visibility helpers.
















 



# app/avo/fields/progress_bar_field.rb
class ProgressBarField < Avo::Fields::BaseField
  attr_reader :max
  attr_reader :step
  attr_reader :display_value
  attr_reader :value_suffix

  def initialize(name, **args, &block)
    super(name, **args, &block)

    @max = args[:max] || 100
    @step = args[:step] || 1
    @display_value = args[:display_value] || false
    @value_suffix = args[:value_suffix] || nil

    hide_on :forms
  end
end

# Customize the views

No let's do something about those views. Let's add a progress bar to the index and show views.

# app/components/avo/fields/progress_bar_field/show_component.html.erb
<%= show_field_wrapper field: @field, index: @index do %>
  <!-- If display_value is set to true, show the value above the progress bar -->
  <% if @field.display_value %>
    <div class="text-center text-sm font-semibold w-full leading-none mb-1">
      <!-- Add the suffix if value_suffix is set -->
      <%= @field.value %><%= @field.value_suffix if @field.value_suffix.present? %>
    </div>
  <% end %>

  <!-- Show the progress input with the settings we passed to the field. -->
  <progress max="<%= @field.max %>" value="<%= @field.value %>" class="block w-full"></progress>
<% end %>

# app/components/avo/fields/progress_bar_field/index_component.html.erb
<%= index_field_wrapper field: @field do %>
  <!-- If display_value is set to true, show the value above the progress bar -->
  <% if @field.display_value %>
    <div class="text-center text-sm font-semibold w-full leading-none mb-1">
      <!-- Add the suffix if value_suffix is set -->
      <%= @field.value %><%= @field.value_suffix if @field.value_suffix.present? %>
    </div>
  <% end %>

  <!-- Show the progress input with the settings we passed to the field. -->
  <progress max="<%= @field.max %>" value="<%= @field.value %>" class="block w-24"></progress>
<% end %>
Progress bar custom field on index

For the edit view we're going to do something different. We'll implement a range input.

<%= edit_field_wrapper field: @field, index: @index, form: @form, resource: @resource, displayed_in_modal: @displayed_in_modal do %>
  <!-- Show the progress input with the settings we passed to the field. -->
  <% if @field.display_value %>
    <div class="text-center text-sm font-semibold w-full leading-none mb-1">
      <!-- Add the suffix if value_suffix is set -->
      <span class="js-progress-bar-value-<%= @field.id %>"><%= @field.value %></span><%= @field.value_suffix if @field.value_suffix.present? %>
    </div>
  <% end %>
  <!-- Add the range input with the settings we passed to the field -->
  <%= @form.range_field @field.id,
    class: 'w-full',
    placeholder: @field.placeholder,
    disabled: @field.readonly,
    min: 0,
    # add the field-specific options
    max: @field.max,
    step: @field.step,
    %>
<% end %>

<script>
// Get the input and value elements
var input = document.getElementById('project_progress');
// Scope the selector to the current field. You might have more than one progress field on the page.
var log = document.querySelector('.js-progress-bar-value-<%= @field.id %>');

// Add event listener for when the input is updated
input.addEventListener('input', updateValue);

// Update the value element with the value from the input
function updateValue(e) {
  log.textContent = e.target.value;
}
</script>
Progress bar custom field edit

# Field assets

Because there isn't just one standardized way of handling assets in Rails, we decided we won't provide asset loading support for custom fields for now. This doesn't mean that you can't use custom assets (javascript or css files), but that you will have to load them in your own pipeline in dedicated Avo files.

In the example above we added the javascript on the page just to demonstrate the functionality. In reality you might add that to a stimulus controller inside your own Avo dedicated pipeline (webpacker or sprockets).

There are also some styles that were added in the asset pipeline directly.

progress {
  @apply h-2 bg-white border border-gray-400 rounded shadow-inner;
}
progress[value]::-webkit-progress-bar {
  @apply bg-white border border-gray-500 rounded shadow-inner;
}
progress[value]::-webkit-progress-value{
  @apply bg-green-600 rounded;

}
progress[value]::-moz-progress-bar {
  @apply bg-green-600 rounded appearance-none;
}