Update Dropdown API (#613)

I'm preparing `Dropdown` component to be used in dotcom and later promoting it to beta. With that in mind, 

### Breaking changes

- Renamed `Dropdown` and `Dropdown::Menu` removing the suffix.
- Updated the `button` slot to be called `summary` and use `system_arguments` instead of relying in the `summary_classes` attribute.

### Dropdown::Menu

Before this update, we always built the menu using:

```html
<ul>
  <li class="dropdown-item">text</li>
...
```

but this isn't always how we use Dropdows, so I updated `Dropdown::Menu` to either render items using a `<ul><li><item_tag>` structure or just adding the tags inside `details-menu`

Author: manuelpuyol

CHANGELOG.md

@@ -2,18 +2,30 @@
 
 ## main
 
+### Updates
+
+* Allow `Dropdown` menu items to be rendered outside a list.
+
+    *Manuel Puyol*
+
 ### Breaking changes
 
 * Require a label or `aria-label` to be provided for `AutoComplete` component.
 
     *Kate Higa*
 
 * Renames:
+  * `DropdownComponent` to `Dropdown`.
+  * `Dropdown::MenuComponent` to `Dropdown::Menu`.
   * `Primer::ButtonMarketingComponent` to `Primer::Alpha::ButtonMarketing`.
   * `Primer::TextComponent` to `Primer::Beta::Text`.
 
     *Manuel Puyol*
 
+* Removes `summary_classes` attribute in favor of the `summary` slot in `Dropdown`.
+
+    *Manuel Puyol*
+
 ### Misc
 
 * Add linter suggestions for `Button` component.
@@ -32,11 +44,11 @@
 
     *Manuel Puyol, Kate Higa*
 
-## 0.0.43
+* Add preliminary criteria for new `alpha` components.
 
-* Upgrade primer/css to 17.2.1
+    *Joel Hawksley*
 
-  *Jon Rohan*
+## 0.0.43
 
 ### New
 
@@ -78,9 +90,9 @@
 
     *Manuel Puyol*
 
-* Add preliminary criteria for new `alpha` components.
+* Upgrade primer/css to 17.2.1
 
-    *Joel Hawksley*
+  *Jon Rohan*
 
 ## 0.0.42
 

app/assets/javascripts/primer_view_components.js

@@ -1,6 +1,7 @@
 <%= render(Primer::DetailsComponent.new(**@system_arguments)) do |c| %>
-  <% c.summary(classes: @summary_classes) do %>
+  <% c.summary(**@button_arguments) do %>
     <%= button %>
+    <% if @with_caret %><div class="dropdown-caret"></div><% end %>
   <% end %>
 
   <% c.body do %>

app/assets/javascripts/primer_view_components.js.map

@@ -0,0 +1,149 @@
+# frozen_string_literal: true
+
+module Primer
+  # `Dropdown` is a lightweight context menu for housing navigation and actions.
+  # They're great for instances where you don't need the full power (and code) of the SelectMenu.
+  class Dropdown < Primer::Component
+    # Required trigger for the dropdown. Has the same arguments as <%= link_to_component(Primer::ButtonComponent) %>,
+    # but it is locked as a `summary` tag.
+    renders_one :button, lambda { |**system_arguments, &block|
+      @button_arguments = system_arguments
+      @button_arguments[:button] = true
+
+      view_context.capture { block&.call }
+    }
+
+    # Required context menu for the dropdown.
+    #
+    # @param as [Symbol] When `as` is `:list`, wraps the menu in a `<ul>` with a `<li>` for each item.
+    # @param direction [Symbol] <%= one_of(Primer::Dropdown::Menu::DIRECTION_OPTIONS) %>
+    # @param scheme [Symbol] Pass `:dark` for dark mode theming
+    # @param header [String] Optional string to display as the header
+    # @param system_arguments [Hash] <%= link_to_system_arguments_docs %>
+    renders_one :menu, "Primer::Dropdown::Menu"
+
+    # @example Default
+    #   <%= render(Primer::Dropdown.new) do |c| %>
+    #     <% c.button do %>
+    #       Dropdown
+    #     <% end %>
+    #
+    #     <%= c.menu(header: "Options") do |menu|
+    #       menu.item { "Item 1" }
+    #       menu.item { "Item 2" }
+    #       menu.item { "Item 3" }
+    #     end %>
+    #   <% end %>
+    #
+    # @example With dividers
+    #
+    #   @description
+    #     Dividers can be used to separate a group of items. They don't have any content.
+    #   @code
+    #     <%= render(Primer::Dropdown.new) do |c| %>
+    #       <% c.button do %>
+    #         Dropdown
+    #       <% end %>
+    #
+    #       <%= c.menu(header: "Options") do |menu|
+    #         menu.item { "Item 1" }
+    #         menu.item { "Item 2" }
+    #         menu.item(divider: true)
+    #         menu.item { "Item 3" }
+    #         menu.item { "Item 4" }
+    #         menu.item(divider: true)
+    #         menu.item { "Item 5" }
+    #         menu.item { "Item 6" }
+    #       end %>
+    #     <% end %>
+    #
+    # @example With direction
+    #   <%= render(Primer::Dropdown.new(display: :inline_block)) do |c| %>
+    #     <% c.button do %>
+    #       Dropdown
+    #     <% end %>
+    #
+    #     <%= c.menu(header: "Options", direction: :s) do |menu|
+    #       menu.item { "Item 1" }
+    #       menu.item { "Item 2" }
+    #       menu.item { "Item 3" }
+    #       menu.item { "Item 4" }
+    #     end %>
+    #   <% end %>
+    #
+    # @example With caret
+    #   <%= render(Primer::Dropdown.new(with_caret: true)) do |c| %>
+    #     <% c.button do %>
+    #       Dropdown
+    #     <% end %>
+    #
+    #     <%= c.menu(header: "Options") do |menu|
+    #       menu.item { "Item 1" }
+    #       menu.item { "Item 2" }
+    #       menu.item { "Item 3" }
+    #       menu.item { "Item 4" }
+    #     end %>
+    #   <% end %>
+    #
+    # @example Customizing the button
+    #   <%= render(Primer::Dropdown.new) do |c| %>
+    #     <% c.button(scheme: :primary, variant: :small) do %>
+    #       Dropdown
+    #     <% end %>
+    #
+    #     <%= c.menu(header: "Options") do |menu|
+    #       menu.item { "Item 1" }
+    #       menu.item { "Item 2" }
+    #       menu.item { "Item 3" }
+    #       menu.item { "Item 4" }
+    #     end %>
+    #   <% end %>
+    #
+    # @example Menu as list
+    #   <%= render(Primer::Dropdown.new) do |c| %>
+    #     <% c.button do %>
+    #       Dropdown
+    #     <% end %>
+    #
+    #     <%= c.menu(as: :list, header: "Options") do |menu|
+    #       menu.item { "Item 1" }
+    #       menu.item { "Item 2" }
+    #       menu.item(divider: true)
+    #       menu.item { "Item 3" }
+    #       menu.item { "Item 4" }
+    #     end %>
+    #   <% end %>
+    #
+    # @example Customizing menu items
+    #   <%= render(Primer::Dropdown.new) do |c| %>
+    #     <% c.button do %>
+    #       Dropdown
+    #     <% end %>
+    #
+    #     <%= c.menu(header: "Options") do |menu|
+    #       menu.item(tag: :button) { "Item 1" }
+    #       menu.item(classes: "custom-class") { "Item 2" }
+    #       menu.item { "Item 3" }
+    #     end %>
+    #   <% end %>
+    #
+    # @param overlay [Symbol] <%= one_of(Primer::DetailsComponent::OVERLAY_MAPPINGS.keys) %>
+    # @param with_caret [Boolean] Whether or not a caret should be rendered in the button.
+    # @param system_arguments [Hash] <%= link_to_system_arguments_docs %>
+    def initialize(overlay: :default, with_caret: false, **system_arguments)
+      @with_caret = with_caret
+
+      @system_arguments = system_arguments
+      @system_arguments[:overlay] = overlay
+      @system_arguments[:reset] = true
+      @system_arguments[:classes] = class_names(
+        @system_arguments[:classes],
+        "dropdown"
+      )
+    end
+
+    def render?
+      button.present? && menu.present?
+    end
+  end
+end

app/components/primer/dropdown_component.html.erb renamed to app/components/primer/dropdown.html.erb

@@ -0,0 +1 @@
+import './dropdown/menu'

app/components/primer/dropdown.rb

@@ -0,0 +1,25 @@
+<%= render Primer::BaseComponent.new(**@system_arguments) do %>
+  <% if @header.present? %>
+    <div class="dropdown-header">
+      <%= @header %>
+    </div>
+  <% end %>
+
+  <% if list? %>
+    <ul>
+      <% items.each do |item| %>
+        <% if item.divider? %>
+          <%= item %>
+        <% else %>
+          <li>
+            <%= item %>
+          </li>
+        <% end %>
+      <% end %>
+    </ul>
+  <% else %>
+    <% items.each do |item| %>
+      <%= item %>
+    <% end %>
+  <% end %>
+<% end %>

app/components/primer/dropdown.ts

@@ -0,0 +1,99 @@
+# frozen_string_literal: true
+
+module Primer
+  class Dropdown
+    # This component is part of `Dropdown` and should not be
+    # used as a standalone component.
+    class Menu < Primer::Component
+      AS_DEFAULT = :default
+      AS_OPTIONS = [AS_DEFAULT, :list].freeze
+
+      SCHEME_DEFAULT = :default
+      SCHEME_MAPPINGS = {
+        SCHEME_DEFAULT => "",
+        :dark => "dropdown-menu-dark"
+      }.freeze
+
+      DIRECTION_DEFAULT = :se
+      DIRECTION_OPTIONS = [DIRECTION_DEFAULT, :sw, :w, :e, :ne, :s].freeze
+
+      # @param tag [Symbol] <%= one_of(Primer::Dropdown::Menu::Item::TAG_OPTIONS) %>.
+      # @param divider [Boolean] Whether the item is a divider without any function.
+      # @param system_arguments [Hash] <%= link_to_system_arguments_docs %>
+      renders_many :items, lambda { |divider: false, **system_arguments|
+        Primer::Dropdown::Menu::Item.new(as: @as, divider: divider, **system_arguments)
+      }
+
+      # @param as [Symbol] When `as` is `:list`, wraps the menu in a `<ul>` with a `<li>` for each item.
+      # @param direction [Symbol] <%= one_of(Primer::Dropdown::Menu::DIRECTION_OPTIONS) %>.
+      # @param header [String] Header to be displayed above the menu.
+      # @param system_arguments [Hash] <%= link_to_system_arguments_docs %>
+      def initialize(as: AS_DEFAULT, direction: DIRECTION_DEFAULT, scheme: SCHEME_DEFAULT, header: nil, **system_arguments)
+        @header = header
+        @direction = direction
+        @as = fetch_or_fallback(AS_OPTIONS, as, AS_DEFAULT)
+
+        @system_arguments = system_arguments
+        @system_arguments[:tag] = "details-menu"
+        @system_arguments[:role] = "menu"
+
+        @system_arguments[:classes] = class_names(
+          @system_arguments[:classes],
+          "dropdown-menu",
+          "dropdown-menu-#{fetch_or_fallback(DIRECTION_OPTIONS, direction, DIRECTION_DEFAULT)}",
+          SCHEME_MAPPINGS[fetch_or_fallback(SCHEME_MAPPINGS.keys, scheme, SCHEME_DEFAULT)]
+        )
+      end
+
+      private
+
+      def list?
+        @as == :list
+      end
+
+      # Items to be rendered in the `Dropdown` menu.
+      class Item < Primer::Component
+        TAG_DEFAULT = :a
+        BUTTON_TAGS = [:button, :summary].freeze
+        TAG_OPTIONS = [TAG_DEFAULT, *BUTTON_TAGS].freeze
+
+        def initialize(as:, tag: TAG_DEFAULT, divider: false, **system_arguments)
+          @divider = divider
+          @as = as
+
+          @system_arguments = system_arguments
+          @system_arguments[:tag] = fetch_or_fallback(TAG_OPTIONS, tag, TAG_DEFAULT)
+          @system_arguments[:tag] = :li if list? && divider?
+          @system_arguments[:role] ||= :menuitem
+          @system_arguments[:role] = :separator if divider
+          @system_arguments[:classes] = class_names(
+            @system_arguments[:classes],
+            "dropdown-item" => !divider,
+            "dropdown-divider" => divider
+          )
+        end
+
+        def call
+          component = if BUTTON_TAGS.include?(@system_arguments[:tag])
+                        Primer::ButtonComponent.new(scheme: :link, **@system_arguments)
+                      else
+                        Primer::BaseComponent.new(**@system_arguments)
+                      end
+
+          # divider has no content
+          render(component) if divider?
+
+          render(component) { content }
+        end
+
+        def divider?
+          @divider
+        end
+
+        def list?
+          @as == :list
+        end
+      end
+    end
+  end
+end

app/components/primer/dropdown/menu.html.erb

@@ -0,0 +1 @@
+import '@github/details-menu-element'