basecoat/docs/_components/popover.njk

{% macro popover(
  id=None,
  trigger=None,
  main_attrs=None,
  trigger_attrs=None,
  content_attrs=None
) %}
{% if registerComponent('popover') %}
<script>
  document.addEventListener('alpine:init', () => {
    Alpine.data('popover', () => ({
      open: false,
      focusedIndex: null,
      menuItems: [],

      init() {
        this.$nextTick(() => {
          this.menuItems = Array.from(this.$el.querySelectorAll('[role=menuitem]'));
        });
      },
      
      handleTriggerClick() {
        this.open = !this.open;
      },
      
      handleEscape() {
        if (this.open) this.open = false;
      },

      focusNavItem() {
        if (this.menuItems.length === 0) return;
        if (this.focusedIndex >= this.menuItems.length) {
          this.focusedIndex = this.menuItems.length - 1;
        }
        if (this.focusedIndex < 0) {
          this.focusedIndex = 0;
        }
        this.menuItems[this.focusedIndex].focus();
      },
      
      nextNavItem() {
        if (this.menuItems.length === 0) return;
        if (this.focusedIndex === null) {
          this.focusedIndex = 0;
        } else {
          this.focusedIndex++;
        }
        this.focusNavItem();
      },
      
      prevNavItem() {
        if (this.menuItems.length === 0) return;
        if (this.focusedIndex === null) {
          this.focusedIndex = 0;
        } else {
          this.focusedIndex--;
        }
        this.focusNavItem();
      },

      handleNavItemClick(event) {
        if (this.menuItems.length === 0) return;
        const menuItem = event.target.closest('[role=menuitem]');
        if (menuItem && !menuItem.disabled) {
          menuItem.blur();
          this.open = false;
        }
      },

      $trigger: {
        '@click'() { this.handleTriggerClick() },
        '@keydown.down.prevent'() { this.open && this.nextNavItem() },
        ':aria-expanded'() { return this.open },
      },
      
      $content: {
        '@click'(e) { this.handleNavItemClick(e) },
        '@keydown.escape.window'() { this.handleEscape() },
        '@keydown.down.prevent'() { this.nextNavItem() },
        '@keydown.up.prevent'() { this.prevNavItem() },
        '@keydown.home.prevent'() { this.focusNavItem(0) },
        '@keydown.end.prevent'() { this.focusNavItem(this.menuItems.length - 1) },
        ':aria-hidden'() { return !this.open },
        'x-cloak': ''
      },
    }));
  });
</script>
{% endif %}

<div
  class="popover {% if main_attrs %}{{ main_attrs.pop('class', '') }}{% endif %}"
  x-data="popover"
  @click.away="open = false"
  {% if id %}id="{{ id }}"{% endif %}
  {% for key, value in main_attrs %}
    {{ key }}="{{ value }}"
  {% endfor %}
>
  {% if trigger %}
  <button
    type="button"
    aria-haspopup="menu"
    aria-expanded="false"
    x-bind="$trigger"
    {% if id %}
    id="{{ id }}-trigger"
    aria-controls="{{ id }}-menu"
    {% endif %}
    {% for key, value in trigger_attrs %}
      {{ key }}="{{ value }}"
    {% endfor %}
  >
    {{ trigger | safe }}
  </button>
  {% endif %}
  <div
    data-popover
    aria-hidden="true"
    x-bind="$content"
    {% if id %}id="{{ id }}-menu"{% endif %}
    {% for key, value in content_attrs %}
      {{ key }}="{{ value }}"
    {% endfor %}
  >
    {{ caller() }}
  </div>
</div>
{% endmacro %}