show()

in Legacy.Monolith/Scripts/bootstrap.esm.js [2050:2110]

• 42 lines of code
• 13 McCabe index (conditional complexity)

  show() {
    if (isDisabled(this._element) || this._menu.classList.contains(CLASS_NAME_SHOW$7)) {
      return;
    }

    const parent = Dropdown.getParentFromElement(this._element);
    const relatedTarget = {
      relatedTarget: this._element
    };
    const showEvent = EventHandler.trigger(this._element, EVENT_SHOW$4, relatedTarget);

    if (showEvent.defaultPrevented) {
      return;
    } // Totally disable Popper for Dropdowns in Navbar


    if (this._inNavbar) {
      Manipulator.setDataAttribute(this._menu, 'popper', 'none');
    } else {
      if (typeof Popper === 'undefined') {
        throw new TypeError('Bootstrap\'s dropdowns require Popper (https://popper.js.org)');
      }

      let referenceElement = this._element;

      if (this._config.reference === 'parent') {
        referenceElement = parent;
      } else if (isElement(this._config.reference)) {
        referenceElement = getElement(this._config.reference);
      } else if (typeof this._config.reference === 'object') {
        referenceElement = this._config.reference;
      }

      const popperConfig = this._getPopperConfig();

      const isDisplayStatic = popperConfig.modifiers.find(modifier => modifier.name === 'applyStyles' && modifier.enabled === false);
      this._popper = Popper.createPopper(referenceElement, this._menu, popperConfig);

      if (isDisplayStatic) {
        Manipulator.setDataAttribute(this._menu, 'popper', 'static');
      }
    } // If this is a touch-enabled device we add extra
    // empty mouseover listeners to the body's immediate children;
    // only needed because of broken event delegation on iOS
    // https://www.quirksmode.org/blog/archives/2014/02/mouse_event_bub.html


    if ('ontouchstart' in document.documentElement && !parent.closest(SELECTOR_NAVBAR_NAV)) {
      [].concat(...document.body.children).forEach(elem => EventHandler.on(elem, 'mouseover', noop));
    }

    this._element.focus();

    this._element.setAttribute('aria-expanded', true);

    this._menu.classList.toggle(CLASS_NAME_SHOW$7);

    this._element.classList.toggle(CLASS_NAME_SHOW$7);

    EventHandler.trigger(this._element, EVENT_SHOWN$4, relatedTarget);
  }