Resource tools

Similar to adding custom fields to a resource, you can add custom tools. A custom tool is a partial added to your resource's Show and Edit views.

Generate a resource tool

Run bin/rails generate avo:resource_tool post_info. That will create two files. The configuration file app/avo/resource_tools/post_info.rb and the partial file app/views/avo/resource_tools/_post_info.html.erb.

The configuration file holds the tool's name and the partial path if you want to override it.

class Avo::ResourceTools::PostInfo < Avo::BaseResourceTool
  self.name = "Post info"
  # self.partial = "avo/resource_tools/post_info"
end

The partial is ready for you to customize further.

<div class="flex flex-col">
  <%= render Avo::PanelComponent.new title: "Post info" do |c| %>
    <% c.with_tools do %>
      <%= a_link('/avo', icon: 'heroicons/solid/academic-cap', style: :primary) do %>
        Dummy link
      <% end %>
    <% end %>

    <% c.with_body do %>
      <div class="flex flex-col p-4 min-h-24">
        <div class="space-y-4">
          <h3>🪧 This partial is waiting to be updated</h3>

          <p>
            You can edit this file here <code class="p-1 rounded bg-gray-500 text-white text-sm">app/views/avo/resource_tools/post_info.html.erb</code>.
          </p>

          <p>
            The resource tool configuration file should be here <code class="p-1 rounded bg-gray-500 text-white text-sm">app/avo/resource_tools/post_info.rb</code>.
          </p>

          <%
            # In this partial, you have access to the following variables:
            # tool
            # @resource
            # @resource.model
            # form (on create & edit pages. please check for presence first)
            # params
            # Avo::Current.context
            # current_user
          %>
        </div>
      </div>
    <% end %>
  <% end %>
</div>

Partial context

You might need access to a few things in the partial.

You have access to the tool, which is an instance of your tool PostInfo, and the @resource, which holds all the information about that particular resource (view, model, params, and others), the params of the request, the Avo::Current.context and the current_user. That should give you all the necessary data to scope out the partial content.

Tool visibility

The resource tool is default visible on the Show view of a resource. You can change that using the visibility options (show_on, only_on).

# app/avo/resources/post.rb
class Avo::Resources::Post < Avo::BaseResource
  def fields
    tool Avo::ResourceTools::PostInfo, show_on: :edit
  end
end

Using path helpers

Because you're in a Rails engine, you will have to prepend the engine object to the path.

For Avo paths

Instead of writing resources_posts_path(1) you have to write avo.resources_posts_path(1).

For the main app paths

When you want to reference paths from your main app, instead of writing posts_path(1), you have to write main_app.posts_path.

Add custom fields on forms

From Avo 2.12

You might want to add a few more fields or pieces of functionality besides the CRUD-generated fields on your forms. Of course, you can already create new custom fields to do it in a more structured way, but you can also use a resource tool to achieve more custom behavior.

You have access to the form object that is available on the new/edit pages on which you can attach inputs of your choosing. You can even achieve nested form functionality.

You have to follow three steps to enable this functionality:

1. Add the inputs in a resource tool and enable the tool on the form pages
2. Tell Avo which params it should permit to write to the model
3. Make sure the model is equipped to receive the params

In the example below, we'll use the Avo::Resources::Fish, add a few input fields (they will be a bit unstyled because this is not the scope of the exercise), and do some actions with some of them.

We first need to generate the tool with bin/rails g avo:resource_tool fish_information and add the tool to the resource file.

class Avo::ResourcesFish < Avo::BaseResource
  def fields
    tool Avo::ResourceTools::FishInformation, show_on: :forms
  end
end

In the _fish_information.html.erb partial, we'll add a few input fields. Some are directly on the form, and some are nested with form.fields_for.

The fields are:

• fish_type as a text input
• properties as a multiple text input which will produce an array in the back-end
• information as nested inputs which will produce a Hash in the back-end

<!-- _fish_information.html.erb -->
<div class="flex flex-col">
  <%= render Avo::PanelComponent.new(title: @resource.model.name) do |c| %>
    <% c.with_tools do %>
      <%= a_link('/admin', icon: 'heroicons/solid/academic-cap', style: :primary) do %>
        Primary
      <% end %>
    <% end %>

    <% c.with_body do %>
      <div class="flex flex-col p-4 min-h-24">
        <div class="space-y-4">
          <% if form.present? %>
            <%= form.label :fish_type %>
            <%= form.text_field :fish_type, value: 'default type of fish', class: input_classes %>
            <br>

            <%= form.label :properties %>
            <%= form.text_field :properties, multiple: true, value: 'property 1', class: input_classes %>
            <%= form.text_field :properties, multiple: true, value: 'property 2', class: input_classes %>
            <br>

            <% form.fields_for :information do |information_form| %>
              <%= form.label :information_name %>
              <%= information_form.text_field :name, value: 'information name', class: input_classes %>
              <div class="text-gray-600 mt-2 text-sm">This is going to be passed to the model</div>
              <br>
              <%= form.label :information_history %>
              <%= information_form.text_field :history, value: 'information history', class: input_classes %>
              <div class="text-gray-600 mt-2 text-sm">This is going to be passed to the model</div>
              <br>
              <%= form.label :information_age %>
              <%= information_form.text_field :age, value: 'information age', class: input_classes %>
              <div class="text-gray-600 mt-2 text-sm">This is NOT going to be passed to the model</div>
            <% end %>
          <% end %>
        </div>
      </div>
    <% end %>
  <% end %>
</div>

Next, we need to tell Avo and Rails which params are welcomed in the create/update request. We do that using the extra_params option on the Avo::Resources::Fish. Avo's internal implementation is to assign the attributes you specify here to the underlying model (model.assign_attributes params.permit(extra_params)).

class Avo::Resources::Fish < Avo::BaseResource
  self.extra_params = [:fish_type, :something_else, properties: [], information: [:name, :history]]

  def fields
    tool Avo::ResourceTools::FishInformation, show_on: :forms
  end
end

The third step is optional. You must ensure your model responds to the params you're sending. Our example should have the fish_type, properties, and information attributes or setter methods on the model class. We chose to add setters to demonstrate the params are called to the model.

class Fish < ApplicationRecord
  self.inheritance_column = nil # required in order to use the type DB attribute

  def fish_type=(value)
    self.type = value
  end

  def properties=(value)
    # properties should be an array
    puts ["properties in the Fish model->", value].inspect
  end

  def information=(value)
    # properties should be a hash
    puts ["information in the Fish model->", value].inspect
  end
end

If you run this code, you'll notice that the information.information_age param will not reach the information= method because we haven't allowed it in the extra_params option.

Where to add logic

It's a good practice not to keep login in view files (partials). You can hide that logic inside the tool using instance variables and methods, and access it in the partial using the tool variable.

Here's an example on how you could do that.

class Avo::ResourceTools::PostInfo < Avo::BaseResourceTool
  self.name = "Post info"
  # self.partial = "avo/resource_tools/post_info"

  attr_reader :foo

  def initialize(**kwargs)
    super **kwargs # It's important to call super with the same keyword arguments

    # You'll have access to the following objects:
    # resource - when attached to a resource
    # parent - which is the object it's attached to (resource if attached to a resource)
    # view

    @foo = :bar # Add your variables
  end

  def custom_method_call
    :called
  end
end

<div class="flex flex-col">
  <%= render Avo::PanelComponent.new title: "Post info" do |c| %>

    <% c.with_body do %>
      <p>
        This variable was declared in the initializer:
        <%= tool.foo %>
      </p>

      <p>
        This is a method called on the tool:
        <%= tool.custom_method_call %>
      </p>
    <% end %>
  <% end %>
</div>