Created
May 2, 2018 23:10
-
-
Save geotrev/a2d367f3996359e910cb6bfb41c1da39 to your computer and use it in GitHub Desktop.
Lightbox Class
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| // Example: | |
| // | |
| // Include a link anywhere in the document: | |
| // <a data-lightbox-button href='#' id="lightbox-1">lightbox 1</a> | |
| // | |
| // Then include the lightbox itself at the end of your <body> content: | |
| // <div data-lightbox-overlay data-lightbox-1> | |
| // <div class='lightbox-content' aria-labelledby="lightbox-heading-1" role="dialog"> | |
| // <header> | |
| // <h2 id="lightbox-heading-1">Lightbox Heading</h2> | |
| // <a data-lightbox-close href='#'>x</a> | |
| // </header> | |
| // <section> | |
| // <p>This is some body content 1</p> | |
| // <button>This is a button</button> | |
| // </section> | |
| // <footer> | |
| // <a data-lightbox-close href='#'>OK</a> | |
| // <a data-lightbox-close href='#'>Cancel</a> | |
| // </footer> | |
| // </div> | |
| // </div> | |
| document.addEventListener('DOMContentLoaded', () => { | |
| new Lightbox() | |
| }) | |
| class Utils { | |
| getFocusableElements(container) { | |
| const tags = [ "a", "button", "input", "object", "select", "textarea", "[tabindex]" ] | |
| let focusables = [], selectors = [] | |
| tags.map(tag => { | |
| focusables.push(`${tag}:not(.is-visually-hidden)`) | |
| }) | |
| focusables.map(selector => { | |
| return selectors.push(`${container} ${selector}`) | |
| }) | |
| const nodes = document.querySelectorAll(selectors.join(", ")) | |
| return Array.apply(null, nodes) | |
| } | |
| trapFocus(container, title, stop = false) { | |
| const children = this.getFocusableElements(container), | |
| firstChild = children[0], | |
| lastChild = children[children.length - 1] | |
| if (stop) { | |
| title.removeEventListener('keydown', (e) => this.handleFocus(e, lastChild, false)) | |
| lastChild.removeEventListener('keydown', (e) => this.handleFocus(e, firstChild, false)) | |
| firstChild.removeEventListener('keydown', (e) => this.handleFocus(e, lastChild, true)) | |
| return | |
| } | |
| title.addEventListener('keydown', (e) => this.handleFocus(e, lastChild, true)) | |
| firstChild.addEventListener('keydown', (e) => this.handleFocus(e, lastChild, true)) | |
| lastChild.addEventListener('keydown', (e) => this.handleFocus(e, firstChild, false)) | |
| } | |
| handleFocus(e, element, shift) { | |
| let shiftKey = shift === true ? e.shiftKey : !e.shiftKey | |
| if (shiftKey && e.which === 9) { | |
| e.preventDefault() | |
| element.focus() | |
| } | |
| } | |
| } | |
| class Lightbox extends Utils { | |
| constructor() { | |
| super() | |
| this.getSelectors() | |
| this.getComponent() | |
| } | |
| getSelectors() { | |
| this.closeButtonAttr = '[data-lightbox-close]' | |
| this.noScrollClass = 'no-scroll'; | |
| this.visibilityAttr = 'data-lightbox-visible' | |
| this.lightboxes = document.querySelectorAll('[data-lightbox-overlay]') | |
| this.lightboxButtons = document.querySelectorAll('[data-lightbox-button]') | |
| this.closeButtons = document.querySelectorAll(this.closeButtonAttr) | |
| this.body = document.body | |
| this.html = document.querySelector('html') | |
| } | |
| getComponent() { | |
| if (this.lightboxButtons.length === 0) return | |
| this.lightboxes.forEach(lightbox => { | |
| lightbox.setAttribute('aria-hidden', 'true') | |
| }) | |
| this.lightboxButtons.forEach(button => { | |
| button.addEventListener('click', (e) => { | |
| e.preventDefault() | |
| this.renderLightbox(button) | |
| }) | |
| }) | |
| } | |
| renderLightbox(button) { | |
| this.stopScroll() | |
| const lightboxAttr = `[data-${button.id}]`, | |
| lightbox = document.querySelector(lightboxAttr), | |
| lightboxContent = lightbox.children[0], | |
| lightboxHeader = document.querySelector(`${lightboxAttr} h2`), | |
| lightboxCloseButtons = document.querySelectorAll(`${lightboxAttr} ${this.closeButtonAttr}`) | |
| this.setupLightbox(lightbox, lightboxAttr, lightboxHeader) | |
| lightboxCloseButtons.forEach(closeButton => { | |
| closeButton.addEventListener('click', (e) => { | |
| e.preventDefault() | |
| this.closeLightbox(lightbox, lightboxAttr, lightboxHeader, button) | |
| }) | |
| }) | |
| } | |
| setupLightbox(container, attr, title) { | |
| this.getLightboxOffset(container) | |
| this.trapFocus(attr, title) | |
| this.watchChildren(container, attr, title) | |
| container.setAttribute(this.visibilityAttr, "") | |
| container.setAttribute('aria-hidden', 'false') | |
| title.setAttribute('tabindex', '-1') | |
| title.focus() | |
| } | |
| closeLightbox(container, attr, title, button) { | |
| container.removeAttribute(this.visibilityAttr) | |
| container.setAttribute('aria-hidden', 'true') | |
| container.removeEventListener('resize', () => this.getOffsetValue(container)) | |
| container.removeEventListener('click', () => this.trapFocus(attr, title)) | |
| this.trapFocus(attr, title, true) | |
| this.returnFocus(button) | |
| this.restoreScroll() | |
| } | |
| watchChildren(container, attr, title) { | |
| container.addEventListener('click', () => this.trapFocus(attr, title)) | |
| } | |
| returnFocus(button) { | |
| button.setAttribute('tabindex', '-1') | |
| button.focus() | |
| button.setAttribute('tabindex', null) | |
| } | |
| getLightboxOffset(container) { | |
| this.getOffsetValue(container) | |
| window.addEventListener('resize', () => this.getOffsetValue(container)) | |
| } | |
| getOffsetValue(container) { | |
| let scrollPosition = Math.round(document.body.scrollTop || window.pageYOffset); | |
| container.style.top = `${scrollPosition}px` | |
| } | |
| restoreScroll() { | |
| this.body.classList.remove(this.noScrollClass) | |
| this.html.classList.remove(this.noScrollClass) | |
| } | |
| stopScroll() { | |
| this.body.classList.add(this.noScrollClass) | |
| this.html.classList.add(this.noScrollClass) | |
| } | |
| } |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment