Allow NavList selection/deselection by id/href in javascript

.changeset/tender-islands-peel.md

@@ -0,0 +1,5 @@
+---
+'@primer/view-components': patch
+---
+
+Allow NavList selection/deselection by id/href in javascript

app/components/primer/alpha/action_list/item.rb

@@ -187,6 +187,9 @@ def initialize(
           @system_arguments[:aria] ||= {}
           @system_arguments[:aria][:disabled] = "true" if @disabled
 
+          @system_arguments[:data] ||= {}
+          @system_arguments[:data][:targets] = "#{list_class.custom_element_name}.items"
+
           @label_arguments = {
             classes: class_names(
               label_classes,
@@ -236,6 +239,10 @@ def before_render
             "ActionListContent--blockDescription" => description && @description_scheme == :block
           )
         end
+
+        def list_class
+          Primer::Alpha::ActionList
+        end
       end
     end
   end

app/components/primer/alpha/nav_list.rb

@@ -17,6 +17,11 @@ module Alpha
     class NavList < Primer::Component
       status :alpha
 
+      # @private
+      def self.custom_element_name
+        "nav-list"
+      end
+
       # Sections. Each section is a list of links and an optional heading.
       #
       # @param system_arguments [Hash] The arguments accepted by <%= link_to_component(Primer::Alpha::NavList::Section) %>.

app/components/primer/alpha/nav_list.ts

@@ -2,8 +2,9 @@
 import {controller, target, targets} from '@github/catalyst'
 
 @controller
-class NavListElement extends HTMLElement {
+export class NavListElement extends HTMLElement {
   @target list: HTMLElement
+  @targets items: HTMLElement[]
   @target showMoreItem: HTMLElement
   @targets focusMarkers: HTMLElement[]
 
@@ -40,6 +41,43 @@ class NavListElement extends HTMLElement {
     return this.showMoreItem.getAttribute('src') || ''
   }
 
+  selectItemById(itemId: string | null): boolean {
+    if (!itemId) return false
+
+    const selectedItem = this.#findSelectedNavItemById(itemId)
+
+    if (selectedItem) {
+      this.#select(selectedItem)
+      return true
+    }
+
+    return false
+  }
+
+  selectItemByHref(href: string | null): boolean {
+    if (!href) return false
+
+    const selectedItem = this.#findSelectedNavItemByHref(href)
+
+    if (selectedItem) {
+      this.#select(selectedItem)
+      return true
+    }
+
+    return false
+  }
+
+  selectItemByCurrentLocation(): boolean {
+    const selectedItem = this.#findSelectedNavItemByCurrentLocation()
+
+    if (selectedItem) {
+      this.#select(selectedItem)
+      return true
+    }
+
+    return false
+  }
+
   // expand collapsible item onClick
   expandItem(item: HTMLElement) {
     item.nextElementSibling?.removeAttribute('data-hidden')
@@ -95,7 +133,7 @@ class NavListElement extends HTMLElement {
       this.currentPage--
       return
     }
-    const fragment = this.parseHTML(document, html)
+    const fragment = this.#parseHTML(document, html)
     fragment?.querySelector('li > a')?.setAttribute('data-targets', 'nav-list.focusMarkers')
     this.list.insertBefore(fragment, this.showMoreItem)
     this.focusMarkers.pop()?.focus()
@@ -114,12 +152,76 @@ class NavListElement extends HTMLElement {
     }
   }
 
-  private parseHTML(document: Document, html: string): DocumentFragment {
+  #parseHTML(document: Document, html: string): DocumentFragment {
     const template = document.createElement('template')
     // eslint-disable-next-line github/no-inner-html
     template.innerHTML = html
     return document.importNode(template.content, true)
   }
+
+  #findSelectedNavItemById(itemId: string): HTMLElement | null {
+    // First we compare the selected link to data-item-id for each nav item
+    for (const navItem of this.items) {
+      const keys = navItem.getAttribute('data-item-id')?.split(' ') || []
+
+      if (keys.includes(itemId)) {
+        return navItem
+      }
+    }
+
+    return null
+  }
+
+  #findSelectedNavItemByHref(href: string): HTMLElement | null {
+    // If we didn't find a match, we compare the selected link to the href of each nav item
+    const selectedNavItem = this.querySelector<HTMLAnchorElement>(`.ActionListContent[href="${href}"]`)
+    if (selectedNavItem) {
+      return selectedNavItem.closest('.ActionListItem')
+    }
+
+    return null
+  }
+
+  #findSelectedNavItemByCurrentLocation(): HTMLElement | null {
+    return this.#findSelectedNavItemByHref(window.location.pathname)
+  }
+
+  #select(navItem: HTMLElement) {
+    const currentlySelectedItem = this.querySelector('.ActionListItem--navActive') as HTMLElement
+    if (currentlySelectedItem) this.#deselect(currentlySelectedItem)
+
+    navItem.classList.add('ActionListItem--navActive')
+
+    const parentMenu = this.#findParentMenu(navItem)
+
+    if (parentMenu) {
+      this.expandItem(parentMenu)
+      parentMenu.classList.add('ActionListContent--hasActiveSubItem')
+    }
+  }
+
+  #deselect(navItem: HTMLElement) {
+    navItem.classList.remove('ActionListItem--navActive')
+
+    const parentMenu = this.#findParentMenu(navItem)
+
+    if (parentMenu) {
+      this.collapseItem(parentMenu)
+      parentMenu.classList.remove('ActionListContent--hasActiveSubItem')
+    }
+  }
+
+  #findParentMenu(navItem: HTMLElement): HTMLElement | null {
+    if (!navItem.classList.contains('ActionListItem--subItem')) return null
+
+    const parent = navItem.closest('li.ActionListItem--hasSubItem')?.querySelector('button.ActionListContent')
+
+    if (parent) {
+      return parent as HTMLElement
+    } else {
+      return null
+    }
+  }
 }
 
 declare global {

app/components/primer/alpha/nav_list/item.rb

@@ -119,6 +119,10 @@ def active_sub_item?
         def current_page?(url)
           helpers.current_page?(url)
         end
+
+        def list_class
+          Primer::Alpha::NavList
+        end
       end
     end
   end

app/components/primer/alpha/nav_list/section.rb

@@ -38,7 +38,7 @@ class Section < ActionList
 
         # @private
         def self.custom_element_name
-          "nav-list"
+          Primer::Alpha::NavList.custom_element_name
         end
 
         # @param selected_item_id [Symbol] The ID of the currently selected item. Used internally.

test/system/alpha/nav_list_test.rb

@@ -29,5 +29,103 @@ def test_shows_more_items
       assert_selector "li", text: "Bachelor Chow"
       assert_selector "li", text: "LöBrau"
     end
+
+    def test_js_api_allows_selecting_item_by_id
+      visit_preview(:default)
+
+      select_item_by_id(:collaborators)
+      assert_item_id_selected(:collaborators)
+    end
+
+    def test_selecting_id_collapses_section
+      visit_preview(:default)
+
+      select_item_by_id(:collaborators)
+      assert_selector "button[aria-expanded=false]", text: "Moderation"
+    end
+
+    def test_js_api_allows_selecting_item_by_href
+      visit_preview(:default)
+
+      select_item_by_href("/collaborators")
+      assert_item_href_selected("/collaborators")
+    end
+
+    def test_selecting_href_collapses_section
+      visit_preview(:default)
+
+      select_item_by_href("/collaborators")
+      assert_selector "button[aria-expanded=false]", text: "Moderation"
+    end
+
+    def test_js_api_allows_selecting_item_by_current_location
+      visit_preview(:default)
+
+      # set the URL without reloading the page
+      page.evaluate_script(<<~JS)
+        (() => {
+          window.history.pushState({}, "", "http://localhost/collaborators")
+        })();
+      JS
+
+      select_item_by_current_location
+      assert_item_href_selected("/collaborators")
+      assert_selector "button[aria-expanded=false]", text: "Moderation"
+    end
+
+    private
+
+    def select_item_by_id(id)
+      select_item_by(id: id)
+    end
+
+    def select_item_by_href(href)
+      select_item_by(href: href)
+    end
+
+    def select_item_by_current_location
+      page.evaluate_script(<<~JS)
+        (() => {
+          const navLists = document.querySelectorAll('nav-list');
+
+          // Unfortunately the NavList component emits multiple <nav-list> elements,
+          // so we have to loop over all of them. This will be addressed in the very
+          // near future.
+          for (const navList of navLists) {
+            if (navList.selectItemByCurrentLocation()) {
+              return;
+            }
+          }
+        })();
+      JS
+    end
+
+    def select_item_by(id: nil, href: nil)
+      func = id ? "selectItemById" : "selectItemByHref"
+      param = id || href
+
+      page.evaluate_script(<<~JS)
+        (() => {
+          const navLists = document.querySelectorAll('nav-list');
+
+          // Unfortunately the NavList component emits multiple <nav-list> elements,
+          // so we have to loop over all of them. This will be addressed in the very
+          // near future.
+          for (const navList of navLists) {
+            if (navList.#{func}('#{param}')) {
+              return;
+            }
+          }
+        })();
+      JS
+    end
+
+    def assert_item_id_selected(item_id)
+      assert_selector("li[data-item-id='#{item_id}'].ActionListItem--navActive")
+    end
+
+    def assert_item_href_selected(item_href)
+      assert_selector("li.ActionListItem--navActive a[href='#{item_href}']")
+    end
   end
 end

test/system/test_case.rb

@@ -9,7 +9,7 @@
 
 module System
   class TestCase < ActionDispatch::SystemTestCase
-    driven_by :cuprite, using: :chrome, screen_size: [1400, 1400], options: { process_timeout: 240, timeout: 240 }
+    driven_by :primer_cuprite, using: :chrome, screen_size: [1400, 1400], options: { process_timeout: 240, timeout: 240 }
 
     # Skip `:region` which relates to preview page structure rather than individual component.
     # Skip `:color-contrast` which requires primer design-level change.

test/test_helpers/cuprite_setup.rb

@@ -5,7 +5,7 @@
 
 # Then, we need to register our driver to be able to use it later
 # with #driven_by method.
-Capybara.register_driver(:cuprite) do |app|
+Capybara.register_driver(:primer_cuprite) do |app|
   Capybara::Cuprite::Driver.new(
     app,
     **{