Dynamic select field

docs/customizing_dashboards.md

@@ -200,7 +200,8 @@ objects to display as.
 
 **Field::Select**
 
-`:collection` - Specify the array or range to select from. Defaults to `[]`.
+`:collection` - Specify the options shown on the select field. It accept either
+an array or an object responding to `:call`. Defaults to `[]`.
 
 `:searchable` - Specify if the attribute should be considered when searching.
 Default is `true`.

lib/administrate/field/select.rb

@@ -14,7 +14,10 @@ def selectable_options
       private
 
       def collection
-        @collection ||= options.fetch(:collection, [])
+        maybe_proc = options.fetch(:collection, [])
+        return maybe_proc.call if maybe_proc.respond_to? :call
+
+        @collection ||= maybe_proc
       end
     end
   end

spec/example_app/app/dashboards/product_dashboard.rb

@@ -7,6 +7,7 @@ class ProductDashboard < Administrate::BaseDashboard
     :description,
     :image_url,
     :product_meta_tag,
+    :release_year,
   ]
 
   ATTRIBUTE_TYPES = {
@@ -17,6 +18,9 @@ class ProductDashboard < Administrate::BaseDashboard
     name: Field::String,
     price: Field::Number.with_options(prefix: "$", decimals: 2),
     product_meta_tag: Field::HasOne,
+    release_year: Field::Select.with_options(
+      collection: -> { (Time.current.year - 10)..Time.current.year },
+    ),
   }
 
   COLLECTION_ATTRIBUTES = ATTRIBUTES

spec/example_app/app/models/product.rb

@@ -6,6 +6,11 @@ class Product < ApplicationRecord
   validates :image_url, presence: true
   validates :name, presence: true
   validates :price, presence: true
+  validates :release_year,
+            numericality: {
+              less_than_or_equal_to: ->(_product) { Time.current.year },
+            },
+            allow_blank: true
   validates :slug, uniqueness: true
   validate :valid_slug
 

spec/example_app/db/migrate/20200326202615_add_release_year_to_products.rb

@@ -0,0 +1,5 @@
+class AddReleaseYearToProducts < ActiveRecord::Migration[6.0]
+  def change
+    add_column :products, :release_year, :integer, limit: 2
+  end
+end

spec/example_app/db/schema.rb

@@ -2,15 +2,15 @@
 # of editing this file, please use the migrations feature of Active Record to
 # incrementally modify your database, and then regenerate this schema definition.
 #
-# Note that this schema.rb definition is the authoritative source for your
-# database schema. If you need to create the application database on another
-# system, you should be using db:schema:load, not running all the migrations
-# from scratch. The latter is a flawed and unsustainable approach (the more migrations
-# you'll amass, the slower it'll run and the greater likelihood for issues).
+# This file is the source Rails uses to define your schema when running `rails
+# db:schema:load`. When creating a new database, `rails db:schema:load` tends to
+# be faster and is potentially less error prone than running all of your
+# migrations from scratch. Old migrations may fail to apply correctly if those
+# migrations use external dependencies or application code.
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20180525115059) do
+ActiveRecord::Schema.define(version: 2020_03_26_202615) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -100,6 +100,7 @@
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
     t.string "slug", null: false
+    t.integer "release_year", limit: 2
     t.index ["slug"], name: "index_products_on_slug", unique: true
   end
 

spec/factories.rb

@@ -44,6 +44,7 @@
       "https://cdn.recombu.com/mobile/images/news/M11370/1264769196_w670.jpg"
     end
     product_meta_tag
+    release_year { [2018, 2019, 2020].sample }
   end
 
   factory :product_meta_tag do

spec/features/products_form_spec.rb

@@ -1,6 +1,8 @@
 require "rails_helper"
 
 describe "product form has_one relationship" do
+  include ActiveSupport::Testing::TimeHelpers
+
   it "saves product and meta tag data correctly" do
     visit new_admin_product_path
 
@@ -21,6 +23,18 @@
     )
   end
 
+  it "have dynamic release_year" do
+    visit new_admin_product_path
+    current_year = Time.current.year
+    expect(page).to have_select("Release year", with_options: [current_year])
+
+    travel_to(1.year.ago) do
+      visit new_admin_product_path
+      expect(page).
+        not_to have_select("Release year", with_options: [current_year])
+    end
+  end
+
   it "edits product and meta tag data correctly" do
     product = create(:product)
 

spec/models/product_spec.rb

@@ -7,6 +7,11 @@
     it { should validate_presence_of(:name) }
     it { should validate_presence_of(:price) }
 
+    it do
+      should validate_numericality_of(:release_year).
+        is_less_than_or_equal_to(Time.now.year)
+    end
+
     it "should not allow names that produce empty slugs" do
       product = build(:product, name: "???")