Create a dashbard generator

[c-lliope]

The generator pulls column names and types from the database,
using the methods #column_names and column_types.

• Fill in missing mappings to BaseDashboard#field_registry.

References:
http://edgeguides.rubyonrails.org/generators.html
https://github.com/ryanb/nifty-generators

When the user runs rails generate dashboard order,
they get a file app/dashboards/order_dashboard.rb with the contents:

require "base_dashboard"

class OrderDashboard < BaseDashboard

  # This method returns 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.
  def attribute_types
    {
      id: :integer,
      customer_id: :integer,
      address_line_one: :string,
      address_line_two: :string,
      address_city: :string,
      address_state: :string,
      address_zip: :string,
      created_at: :datetime,
      updated_at: :datetime,
      customer: :belongs_to,
      line_items: :has_many,
    }
  end

  # This method returns an array of attributes
  # that will be displayed on the model's index page.
  def index_page_attributes
    attributes
  end

  # This method returns an array of attributes
  # that will be displayed on the model's show page
  def show_page_attributes
    attributes
  end

  # This method returns an array of attributes
  # that will be displayed on the model's form pages (`new` and `edit`)
  def form_attributes
    attributes - read_only_attributes
  end

  private

  def attributes
    [
      :id,
      :customer_id,
      :address_line_one,
      :address_line_two,
      :address_city,
      :address_state,
      :address_zip,
      :created_at,
      :updated_at,
      :customer,
      :line_items,
    ]
  end

  def read_only_attributes
    [
      :id,
      :created_at,
      :updated_at,
    ]
  end
end

https://trello.com/c/My9ldlzZ

[houndci-bot]

Prefer double-quoted strings unless you need single quotes to avoid extra backslashes for escaping.

[c-lliope]

• make sure it works for has_many relationships
• make sure it works for belongs_to relationships
• add light comments to describe the API?

[jayroh]

Could you clarify why this file was updated within the context of this commit? Wondering if it is related/within the context of the commit's purpose.

[c-lliope]

No, it's not super related. I updated the structure a little to reflect the generated dashboard.

[c-lliope]

Any thoughts on how to test this?

[sgrif]

attribute_names

[derekprior]

This looks correct to me from a generator standpoint. Is the reflection stuff public API?

Ammeter can help you test the file creation aspect of this, verify the generated file is valid ruby, etc. Faking a model out and all of that reflection seems like it would be hard. I'd probably try to have a real model available for the test.

[sgrif]

Is the reflection stuff public API?

It's probably the most ambiguous part of Active Record as to whether it's public or not. Generally speaking, no.

[c-lliope]

Recommended by @derekprior for testing generators: https://github.com/alexrothenberg/ammeter

Examples:
https://github.com/thoughtbot/clearance/blob/master/spec/support/generator_spec_helpers.rb
https://github.com/thoughtbot/scenic/blob/master/spec/support/generator_spec_setup.rb
https://github.com/thoughtbot/scenic/blob/master/spec/generators/scenic/model/model_generator_spec.rb

[houndci-bot]

Use 2 (not 0) spaces for indenting an expression spanning multiple lines.

[c-lliope]

Related deprecation issues on ActiveAdmin: activeadmin/activeadmin#3930

[c-lliope]

Alright, I'm willing to merge this for a few reasons:

• We're going for an MVP here. The only requirement is that it works with the latest version of Rails (nothing more, nothing less).
• Without a clearer idea of how Rails 5 will be structured, it'll be pretty rough trying to find a forward-compatible solution.
• This is generator code. If people upgrade to Rails 5, their already-generated code will continue to work.
• If worst comes to worst, we can always create adapters for different major versions of Rails.

@sgrif I'm really interested in playing with the Attributes API, and making sure this is forwards-compatible before we launch 1.0. Thanks for the advice with this! I'm sure we'll have some more conversations along similar lines before too long 😄