Administrate::Field::LazyHasMany

An input field that shows search results of has many association, lazily from a custom endpoint.

Add this line to your application's Gemfile:

gem 'administrate-field-lazy_has_many'

And then execute:

$ bundle

Or install it yourself as:

$ gem install administrate-field-lazy_has_many

You need to have a route that does the following:

1. yields an array of objects with at least the value and text you want to show i.e [{value: 1, text: option1}]
2. Respond to search attribute
3. Limit result result_limit

The best way is to re-use everything administrate search feature. You must define this action in administrate related entity controller

     def books_data
      result_limit = params[:result_limit] || 10
      search_term = params[:search].to_s.strip
      resources = Administrate::Search.new(scoped_resource, dashboard_class, search_term).run
      resources = resources.limit(result_limit).map do |resource|
        { value: resource.id, text: dashboard.display_resource(resource) }
      end
      if resources.blank?
        render_empty_array
      else
        render json: resources
      end
    end

Above example action that could work for every model, but you can change the implementation as per need. The only catch is it must return the comply with above conditions.

Field is pretty easy and it does support all the features of administrate has_many field. You can provide all has_many options as per your use case. The only require attribute is action which must be rails path helper.

require "administrate/base_dashboard"

class PostDashboard < Administrate::BaseDashboard
  # ATTRIBUTE_TYPES
  # a hash that describes the type of each of the model's fields.
  #
  # Each different type represents an Administrate::Field object,
  # which determines how the attribute is displayed
  # on pages throughout the dashboard.
  ATTRIBUTE_TYPES = {
    id: Field::String,
    title: Field::String,
    contributors: Field::LazyHasMany.with_options(
      action: 'admin_form_contributors_data_path', result_limit: 10
    ),
    created_at: Field::DateTime,
    updated_at: Field::DateTime
  }.freeze

  # ...
end

i.e result_limit attribute maximum result value the field will post to action endpoint with search paramter

1. Fork it ( https://github.com/Aftab-Akram/administrate-field-lazy_has_many )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

Aftab Akram - LinkedIn - aftabakram04@gmail.com