Avo::Meta

Overview

Avo::Meta equips your Avo application with the ability to add arbitrary "meta" attributes to your resources in a no-code manner.

Under the hood, it leverages a JSON database column and StoreModel to manage it.

Installation

Add this line to your application's Gemfile:

gem "avo-meta", source: "https://packager.dev/avo-hq/"

And then execute:

$ bundle

To use Avo::Meta, an additional database table containing the schemas for each resource has to be created. For this, simply install the necessary migrations:

$ bin/rails avo_meta:install:migrations
$ bin/rails db:migrate

Usage

Preparation

First, add a meta JSON column to your model:

$ bin/rails g migration AddMetaToUsers meta:json
$ bin/rails db:migrate

After that, simply include the Avo::Metaable module in said model:

class User < ApplicationRecord
  include Avo::Metaable
end

This will create two things under the hood:

• a "Meta Properties" resource available in the sidebar. Here, you can add new meta properties for each associated resource by adding a name and a type. Under the hood, it modifies the avo_meta_schemas database table created via the migrations.

NOTE

If the meta JSON column is missing on your model, a reminder to add it will be emitted.

• a meta class attribute for the associated Avo resource (in the example above, the User resource). This class attribute contains the schema definition (essentially a hash containing name, type, as, and other attributes) of the meta entries stored with the model. This will result in a "Meta" panel in your resource New/Show/Edit views where you can edit the defined attributes.

To display the meta panel in your resource view to modify these attributes, simply add meta_panel to your def fields definition:

class Avo::Resources::User < Avo::BaseResource
  # ...

  def fields
    # ...

    meta_panel
  end
end

Accessing Meta Attributes

To use the meta attributes in your application, simply access them like you would access a has_one association:

@user.meta.shoe_size

Menu entry

By default, "Meta Properties" will automatically appear in the sidebar if you are not using a custom menu.

If you are using a custom menu, you need to explicitly add the menu entry:

# config/initializers/avo.rb
Avo.configure do |config|
  config.main_menu = -> {
    section "Meta" do
      resource :meta_schema
    end
  }
end