modal.js

/**
 * --------------------------------------------------------------------------
 * Bootstrap (v5.0.0-beta3): modal.js
 * Licensed under MIT (https://github.com/twbs/bootstrap/blob/main/LICENSE)
 * --------------------------------------------------------------------------
 */

import {
  defineJQueryPlugin,
  emulateTransitionEnd,
  getElementFromSelector,
  getTransitionDurationFromElement,
  isRTL,
  isVisible,
  reflow,
  typeCheckConfig
} from './util/index'
import EventHandler from './dom/event-handler'
import Manipulator from './dom/manipulator'
import SelectorEngine from './dom/selector-engine'
import BaseComponent from './base-component'

/**
 * ------------------------------------------------------------------------
 * Constants
 * ------------------------------------------------------------------------
 */

const NAME = 'modal'
const DATA_KEY = 'bs.modal'
const EVENT_KEY = `.${DATA_KEY}`
const DATA_API_KEY = '.data-api'
const ESCAPE_KEY = 'Escape'

const Default = {
  backdrop: true,
  keyboard: true,
  focus: true
}

const DefaultType = {
  backdrop: '(boolean|string)',
  keyboard: 'boolean',
  focus: 'boolean'
}

const EVENT_HIDE = `hide${EVENT_KEY}`
const EVENT_HIDE_PREVENTED = `hidePrevented${EVENT_KEY}`
const EVENT_HIDDEN = `hidden${EVENT_KEY}`
const EVENT_SHOW = `show${EVENT_KEY}`
const EVENT_SHOWN = `shown${EVENT_KEY}`
const EVENT_FOCUSIN = `focusin${EVENT_KEY}`
const EVENT_RESIZE = `resize${EVENT_KEY}`
const EVENT_CLICK_DISMISS = `click.dismiss${EVENT_KEY}`
const EVENT_KEYDOWN_DISMISS = `keydown.dismiss${EVENT_KEY}`
const EVENT_MOUSEUP_DISMISS = `mouseup.dismiss${EVENT_KEY}`
const EVENT_MOUSEDOWN_DISMISS = `mousedown.dismiss${EVENT_KEY}`
const EVENT_CLICK_DATA_API = `click${EVENT_KEY}${DATA_API_KEY}`

const CLASS_NAME_SCROLLBAR_MEASURER = 'modal-scrollbar-measure'
const CLASS_NAME_BACKDROP = 'modal-backdrop'
const CLASS_NAME_OPEN = 'modal-open'
const CLASS_NAME_FADE = 'fade'
const CLASS_NAME_SHOW = 'show'
const CLASS_NAME_STATIC = 'modal-static'

const SELECTOR_DIALOG = '.modal-dialog'
const SELECTOR_MODAL_BODY = '.modal-body'
const SELECTOR_DATA_TOGGLE = '[data-bs-toggle="modal"]'
const SELECTOR_DATA_DISMISS = '[data-bs-dismiss="modal"]'
const SELECTOR_FIXED_CONTENT = '.fixed-top, .fixed-bottom, .is-fixed, .sticky-top'
const SELECTOR_STICKY_CONTENT = '.sticky-top'

/**
 * ------------------------------------------------------------------------
 * Class Definition
 * ------------------------------------------------------------------------
 */

class Modal extends BaseComponent {
  constructor(element, config) {
    super(element)

    this._config = this._getConfig(config)
    this._dialog = SelectorEngine.findOne(SELECTOR_DIALOG, this._element)
    this._backdrop = null
    this._isShown = false
    this._isBodyOverflowing = false
    this._ignoreBackdropClick = false
    this._isTransitioning = false
    this._scrollbarWidth = 0
  }

  // Getters

  static get Default() {
    return Default
  }

  static get DATA_KEY() {
    return DATA_KEY
  }

  // Public

  toggle(relatedTarget) {
    return this._isShown ? this.hide() : this.show(relatedTarget)
  }

  show(relatedTarget) {
    if (this._isShown || this._isTransitioning) {
      return
    }

    if (this._isAnimated()) {
      this._isTransitioning = true
    }

    const showEvent = EventHandler.trigger(this._element, EVENT_SHOW, {
      relatedTarget
    })

    if (this._isShown || showEvent.defaultPrevented) {
      return
    }

    this._isShown = true

    this._checkScrollbar()
    this._setScrollbar()

    this._adjustDialog()

    this._setEscapeEvent()
    this._setResizeEvent()

    EventHandler.on(this._element, EVENT_CLICK_DISMISS, SELECTOR_DATA_DISMISS, event => this.hide(event))

    EventHandler.on(this._dialog, EVENT_MOUSEDOWN_DISMISS, () => {
      EventHandler.one(this._element, EVENT_MOUSEUP_DISMISS, event => {
        if (event.target === this._element) {
          this._ignoreBackdropClick = true
        }
      })
    })

    this._showBackdrop(() => this._showElement(relatedTarget))
  }

  hide(event) {
    if (event) {
      event.preventDefault()
    }

    if (!this._isShown || this._isTransitioning) {
      return
    }

    const hideEvent = EventHandler.trigger(this._element, EVENT_HIDE)

    if (hideEvent.defaultPrevented) {
      return
    }

    this._isShown = false
    const isAnimated = this._isAnimated()

    if (isAnimated) {
      this._isTransitioning = true
    }

    this._setEscapeEvent()
    this._setResizeEvent()

    EventHandler.off(document, EVENT_FOCUSIN)

    this._element.classList.remove(CLASS_NAME_SHOW)

    EventHandler.off(this._element, EVENT_CLICK_DISMISS)
    EventHandler.off(this._dialog, EVENT_MOUSEDOWN_DISMISS)

    if (isAnimated) {
      const transitionDuration = getTransitionDurationFromElement(this._element)

      EventHandler.one(this._element, 'transitionend', event => this._hideModal(event))
      emulateTransitionEnd(this._element, transitionDuration)
    } else {
      this._hideModal()
    }
  }

  dispose() {
    [window, this._element, this._dialog]
      .forEach(htmlElement => EventHandler.off(htmlElement, EVENT_KEY))

    super.dispose()

    /**
     * `document` has 2 events `EVENT_FOCUSIN` and `EVENT_CLICK_DATA_API`
     * Do not move `document` in `htmlElements` array
     * It will remove `EVENT_CLICK_DATA_API` event that should remain
     */
    EventHandler.off(document, EVENT_FOCUSIN)

    this._config = null
    this._dialog = null
    this._backdrop = null
    this._isShown = null
    this._isBodyOverflowing = null
    this._ignoreBackdropClick = null
    this._isTransitioning = null
    this._scrollbarWidth = null
  }

  handleUpdate() {
    this._adjustDialog()
  }

  // Private

  _getConfig(config) {
    config = {
      ...Default,
      ...Manipulator.getDataAttributes(this._element),
      ...config
    }
    typeCheckConfig(NAME, config, DefaultType)
    return config
  }

  _showElement(relatedTarget) {
    const isAnimated = this._isAnimated()
    const modalBody = SelectorEngine.findOne(SELECTOR_MODAL_BODY, this._dialog)

    if (!this._element.parentNode || this._element.parentNode.nodeType !== Node.ELEMENT_NODE) {
      // Don't move modal's DOM position
      document.body.appendChild(this._element)
    }

    this._element.style.display = 'block'
    this._element.removeAttribute('aria-hidden')
    this._element.setAttribute('aria-modal', true)
    this._element.setAttribute('role', 'dialog')
    this._element.scrollTop = 0

    if (modalBody) {
      modalBody.scrollTop = 0
    }

    if (isAnimated) {
      reflow(this._element)
    }

    this._element.classList.add(CLASS_NAME_SHOW)

    if (this._config.focus) {
      this._enforceFocus()
    }

    const transitionComplete = () => {
      if (this._config.focus) {
        this._element.focus()
      }

      this._isTransitioning = false
      EventHandler.trigger(this._element, EVENT_SHOWN, {
        relatedTarget
      })
    }

    if (isAnimated) {
      const transitionDuration = getTransitionDurationFromElement(this._dialog)

      EventHandler.one(this._dialog, 'transitionend', transitionComplete)
      emulateTransitionEnd(this._dialog, transitionDuration)
    } else {
      transitionComplete()
    }
  }

  _enforceFocus() {
    EventHandler.off(document, EVENT_FOCUSIN) // guard against infinite focus loop
    EventHandler.on(document, EVENT_FOCUSIN, event => {
      if (document !== event.target &&
          this._element !== event.target &&
          !this._element.contains(event.target)) {
        this._element.focus()
      }
    })
  }

  _setEscapeEvent() {
    if (this._isShown) {
      EventHandler.on(this._element, EVENT_KEYDOWN_DISMISS, event => {
        if (this._config.keyboard && event.key === ESCAPE_KEY) {
          event.preventDefault()
          this.hide()
        } else if (!this._config.keyboard && event.key === ESCAPE_KEY) {
          this._triggerBackdropTransition()
        }
      })
    } else {
      EventHandler.off(this._element, EVENT_KEYDOWN_DISMISS)
    }
  }

  _setResizeEvent() {
    if (this._isShown) {
      EventHandler.on(window, EVENT_RESIZE, () => this._adjustDialog())
    } else {
      EventHandler.off(window, EVENT_RESIZE)
    }
  }

  _hideModal() {
    this._element.style.display = 'none'
    this._element.setAttribute('aria-hidden', true)
    this._element.removeAttribute('aria-modal')
    this._element.removeAttribute('role')
    this._isTransitioning = false
    this._showBackdrop(() => {
      document.body.classList.remove(CLASS_NAME_OPEN)
      this._resetAdjustments()
      this._resetScrollbar()
      EventHandler.trigger(this._element, EVENT_HIDDEN)
    })
  }

  _removeBackdrop() {
    this._backdrop.parentNode.removeChild(this._backdrop)
    this._backdrop = null
  }

  _showBackdrop(callback) {
    const isAnimated = this._isAnimated()
    if (this._isShown && this._config.backdrop) {
      this._backdrop = document.createElement('div')
      this._backdrop.className = CLASS_NAME_BACKDROP

      if (isAnimated) {
        this._backdrop.classList.add(CLASS_NAME_FADE)
      }

      document.body.appendChild(this._backdrop)

      EventHandler.on(this._element, EVENT_CLICK_DISMISS, event => {
        if (this._ignoreBackdropClick) {
          this._ignoreBackdropClick = false
          return
        }

        if (event.target !== event.currentTarget) {
          return
        }

        if (this._config.backdrop === 'static') {
          this._triggerBackdropTransition()
        } else {
          this.hide()
        }
      })

      if (isAnimated) {
        reflow(this._backdrop)
      }

      this._backdrop.classList.add(CLASS_NAME_SHOW)

      if (!isAnimated) {
        callback()
        return
      }

      const backdropTransitionDuration = getTransitionDurationFromElement(this._backdrop)

      EventHandler.one(this._backdrop, 'transitionend', callback)
      emulateTransitionEnd(this._backdrop, backdropTransitionDuration)
    } else if (!this._isShown && this._backdrop) {
      this._backdrop.classList.remove(CLASS_NAME_SHOW)

      const callbackRemove = () => {
        this._removeBackdrop()
        callback()
      }

      if (isAnimated) {
        const backdropTransitionDuration = getTransitionDurationFromElement(this._backdrop)
        EventHandler.one(this._backdrop, 'transitionend', callbackRemove)
        emulateTransitionEnd(this._backdrop, backdropTransitionDuration)
      } else {
        callbackRemove()
      }
    } else {
      callback()
    }
  }

  _isAnimated() {
    return this._element.classList.contains(CLASS_NAME_FADE)
  }

  _triggerBackdropTransition() {
    const hideEvent = EventHandler.trigger(this._element, EVENT_HIDE_PREVENTED)
    if (hideEvent.defaultPrevented) {
      return
    }

    const isModalOverflowing = this._element.scrollHeight > document.documentElement.clientHeight

    if (!isModalOverflowing) {
      this._element.style.overflowY = 'hidden'
    }

    this._element.classList.add(CLASS_NAME_STATIC)
    const modalTransitionDuration = getTransitionDurationFromElement(this._dialog)
    EventHandler.off(this._element, 'transitionend')
    EventHandler.one(this._element, 'transitionend', () => {
      this._element.classList.remove(CLASS_NAME_STATIC)
      if (!isModalOverflowing) {
        EventHandler.one(this._element, 'transitionend', () => {
          this._element.style.overflowY = ''
        })
        emulateTransitionEnd(this._element, modalTransitionDuration)
      }
    })
    emulateTransitionEnd(this._element, modalTransitionDuration)
    this._element.focus()
  }

  // ----------------------------------------------------------------------
  // the following methods are used to handle overflowing modals
  // ----------------------------------------------------------------------

  _adjustDialog() {
    const isModalOverflowing = this._element.scrollHeight > document.documentElement.clientHeight

    if ((!this._isBodyOverflowing && isModalOverflowing && !isRTL()) || (this._isBodyOverflowing && !isModalOverflowing && isRTL())) {
      this._element.style.paddingLeft = `${this._scrollbarWidth}px`
    }

    if ((this._isBodyOverflowing && !isModalOverflowing && !isRTL()) || (!this._isBodyOverflowing && isModalOverflowing && isRTL())) {
      this._element.style.paddingRight = `${this._scrollbarWidth}px`
    }
  }

  _resetAdjustments() {
    this._element.style.paddingLeft = ''
    this._element.style.paddingRight = ''
  }

  _checkScrollbar() {
    const rect = document.body.getBoundingClientRect()
    this._isBodyOverflowing = Math.round(rect.left + rect.right) < window.innerWidth
    this._scrollbarWidth = this._getScrollbarWidth()
  }

  _setScrollbar() {
    if (this._isBodyOverflowing) {
      this._setElementAttributes(SELECTOR_FIXED_CONTENT, 'paddingRight', calculatedValue => calculatedValue + this._scrollbarWidth)
      this._setElementAttributes(SELECTOR_STICKY_CONTENT, 'marginRight', calculatedValue => calculatedValue - this._scrollbarWidth)
      this._setElementAttributes('body', 'paddingRight', calculatedValue => calculatedValue + this._scrollbarWidth)
    }

    document.body.classList.add(CLASS_NAME_OPEN)
  }

  _setElementAttributes(selector, styleProp, callback) {
    SelectorEngine.find(selector)
      .forEach(element => {
        if (element !== document.body && window.innerWidth > element.clientWidth + this._scrollbarWidth) {
          return
        }

        const actualValue = element.style[styleProp]
        const calculatedValue = window.getComputedStyle(element)[styleProp]
        Manipulator.setDataAttribute(element, styleProp, actualValue)
        element.style[styleProp] = `${callback(Number.parseFloat(calculatedValue))}px`
      })
  }

  _resetScrollbar() {
    this._resetElementAttributes(SELECTOR_FIXED_CONTENT, 'paddingRight')
    this._resetElementAttributes(SELECTOR_STICKY_CONTENT, 'marginRight')
    this._resetElementAttributes('body', 'paddingRight')
  }

  _resetElementAttributes(selector, styleProp) {
    SelectorEngine.find(selector).forEach(element => {
      const value = Manipulator.getDataAttribute(element, styleProp)
      if (typeof value === 'undefined' && element === document.body) {
        element.style[styleProp] = ''
      } else {
        Manipulator.removeDataAttribute(element, styleProp)
        element.style[styleProp] = value
      }
    })
  }

  _getScrollbarWidth() { // thx d.walsh
    const scrollDiv = document.createElement('div')
    scrollDiv.className = CLASS_NAME_SCROLLBAR_MEASURER
    document.body.appendChild(scrollDiv)
    const scrollbarWidth = scrollDiv.getBoundingClientRect().width - scrollDiv.clientWidth
    document.body.removeChild(scrollDiv)
    return scrollbarWidth
  }

  // Static

  static jQueryInterface(config, relatedTarget) {
    return this.each(function () {
      const data = Modal.getInstance(this) || new Modal(this, typeof config === 'object' ? config : {})

      if (typeof config !== 'string') {
        return
      }

      if (typeof data[config] === 'undefined') {
        throw new TypeError(`No method named "${config}"`)
      }

      data[config](relatedTarget)
    })
  }
}

/**
 * ------------------------------------------------------------------------
 * Data Api implementation
 * ------------------------------------------------------------------------
 */

EventHandler.on(document, EVENT_CLICK_DATA_API, SELECTOR_DATA_TOGGLE, function (event) {
  const target = getElementFromSelector(this)

  if (['A', 'AREA'].includes(this.tagName)) {
    event.preventDefault()
  }

  EventHandler.one(target, EVENT_SHOW, showEvent => {
    if (showEvent.defaultPrevented) {
      // only register focus restorer if modal will actually get shown
      return
    }

    EventHandler.one(target, EVENT_HIDDEN, () => {
      if (isVisible(this)) {
        this.focus()
      }
    })
  })

  const data = Modal.getInstance(target) || new Modal(target)

  data.toggle(this)
})

/**
 * ------------------------------------------------------------------------
 * jQuery
 * ------------------------------------------------------------------------
 * add .Modal to jQuery only if jQuery is present
 */

defineJQueryPlugin(NAME, Modal)

export default Modal