Web site Developer I Advertising I Social Media Advertising I Content material Creators I Branding Creators I Administration I System SolutionReplace JavaScript Dialogs With New HTML Dialog | CSS-Tips

Web site Developer I Advertising I Social Media Advertising I Content material Creators I Branding Creators I Administration I System SolutionReplace JavaScript Dialogs With New HTML Dialog | CSS-Tips

Web site Developer I Advertising I Social Media Advertising I Content material Creators I Branding Creators I Administration I System Answer

You know the way there are JavaScript dialogs for alerting, confirming, and prompting consumer actions? Say you wish to substitute JavaScript dialogs with the brand new HTML dialog component.

Let me clarify.

I just lately labored on a mission with quite a lot of API calls and consumer suggestions gathered with JavaScript dialogs. Whereas I used to be ready for one more developer to code the <Modal /> element, I used alert(), affirm() and immediate() in my code. As an example:

const deleteLocation = affirm('Delete location');
if (deleteLocation) {
  alert('Location deleted');

Then it hit me: you get quite a lot of modal-related options totally free with alert(), affirm(), and immediate() that usually go ignored:

  • It’s a real modal. As in, it would all the time be on prime of the stack — even on prime of that <div> with z-index: 99999;.
  • It’s accessible with the keyboard. Press Enter to simply accept and Escape to cancel.
  • It’s display screen reader-friendly. It strikes focus and permits the modal content material to be learn aloud.
  • It traps focus. Urgent Tab is not going to attain any focusable parts on the principle web page, however in Firefox and Safari it does certainly transfer focus to the browser UI. What’s bizarre although is that you would be able to’t transfer focus to the “settle for” or “cancel” buttons in any browser utilizing the Tab key.
  • It helps consumer preferences. We get computerized gentle and darkish mode help proper out of the field.
  • It pauses code-execution., Plus, it waits for consumer enter.

These three JavaScripts strategies work 99% of the time once I want any of those functionalities. So why don’t I — or actually some other net developer — use them? In all probability as a result of they appear to be system errors that can’t be styled. One other huge consideration: there was motion towards their deprecation. First removing from cross-domain iframes and, phrase is, from the net platform completely, though it additionally feels like plans for which might be on maintain.

With that huge consideration in thoughts, what are alert(), affirm() and immediate() alternate options do we’ve to switch them? You’ll have already heard concerning the <dialog> HTML component and that’s what I wish to take a look at on this article, utilizing it alongside a JavaScript class.

It’s unattainable to utterly substitute Javascript dialogs with equivalent performance, but when we use the showModal() technique of <dialog> mixed with a Promise that may both resolve (settle for) or reject (cancel) — then we’ve one thing virtually nearly as good. Heck, whereas we’re at it, let’s add sound to the HTML dialog component — identical to actual system dialogs!

In the event you’d prefer to see the demo instantly, it’s right here.

A dialog class

First, we’d like a fundamental JavaScript Class with a settings object that might be merged with the default settings. These settings might be used for all dialogs, until you overwrite them when invoking them (however extra on that later).

export default class Dialog {
constructor(settings = {}) {
  this.settings = Object.assign(
      /* DEFAULT SETTINGS - see description beneath */

The settings are:

  • settle for: That is the “Settle for” button’s label.
  • bodyClass: This can be a CSS class that’s added to <physique> component when the dialog is open and <dialog> is unsupported by the browser.
  • cancel: That is the “Cancel” button’s label.
  • dialogClass: This can be a customized CSS class added to the <dialog> component.
  • message: That is the content material contained in the <dialog>.
  • soundAccept: That is the URL to the sound file we’ll play when the consumer hits the “Settle for” button.
  • soundOpen: That is the URL to the sound file we’ll play when the consumer opens the dialog.
  • template: That is an non-obligatory, little HTML template that’s injected into the <dialog>.

The preliminary template to switch JavaScript dialogs

Within the init technique, we’ll add a helper operate for detecting help for the HTML dialog component in browsers, and arrange the fundamental HTML:

init() {
  // Testing for <dialog> help
  this.dialogSupported = typeof HTMLDialogElement === 'operate'
  this.dialog = doc.createElement('dialog')
  this.dialog.dataset.element = this.dialogSupported ? 'dialog' : 'no-dialog'
  // HTML template
  this.dialog.innerHTML = `
  <kind technique="dialog" data-ref="kind">
    <fieldset data-ref="fieldset" position="doc">
      <legend data-ref="message" id="${(Math.spherical(Date.now())).toString(36)}">
      <div data-ref="template"></div>
      <button data-ref="cancel" worth="cancel"></button>
      <button data-ref="settle for" worth="default"></button>
    <audio data-ref="soundAccept"></audio>
    <audio data-ref="soundOpen"></audio>


  // ...

Checking for help

The street for browsers to help <dialog> has been lengthy. Safari picked it up fairly just lately. Firefox much more just lately, although not the <kind technique="dialog"> half. So, we have to add sort="button" to the “Settle for” and “Cancel” buttons we’re mimicking. In any other case, they’ll POST the shape and trigger a web page refresh and we wish to keep away from that.

<button${this.dialogSupported ? '' : ` sort="button"`}...></button>

DOM node references

Did you discover all of the data-ref-attributes? We’ll use these for getting references to the DOM nodes:

this.parts = {}
this.dialog.querySelectorAll('[data-ref]').forEach(el => this.parts[el.dataset.ref] = el)

To this point, this.parts.settle for is a reference to the “Settle for” button, and this.parts.cancel refers back to the “Cancel” button.

Button attributes

For display screen readers, we’d like an aria-labelledby attribute pointing to the ID of the tag that describes the dialog — that’s the <legend> tag and it’ll include the message.

this.dialog.setAttribute('aria-labelledby', this.parts.message.id)

That id? It’s a novel reference to this a part of the <legend> component:

this.dialog.setAttribute('aria-labelledby', this.parts.message.id)

The “Cancel” button

Excellent news! The HTML dialog component has a built-in cancel() technique making it simpler to switch JavaScript dialogs calling the affirm() technique. Let’s emit that occasion once we click on the “Cancel” button:

this.parts.cancel.addEventListener('click on', () => { 
  this.dialog.dispatchEvent(new Occasion('cancel')) 

That’s the framework for our <dialog> to switch alert(), affirm(), and immediate().

Polyfilling unsupported browsers

We have to cover the HTML dialog component for browsers that don’t help it. To try this, we’ll wrap the logic for exhibiting and hiding the dialog in a brand new technique, toggle():

toggle(open = false) {
  if (this.dialogSupported && open) this.dialog.showModal()
  if (!this.dialogSupported) {
    doc.physique.classList.toggle(this.settings.bodyClass, open)
    this.dialog.hidden = !open
    /* If a `goal` exists, set concentrate on it when closing */
    if (this.parts.goal && !open) {
/* Then name it on the finish of `init`: */

Keyboard navigation

Subsequent up, let’s implement a technique to entice focus in order that the consumer can tab between the buttons within the dialog with out inadvertently exiting the dialog. There are lots of methods to do that. I like the CSS method, however sadly, it’s unreliable. As a substitute, let’s seize all focusable parts from the dialog as a NodeList and retailer it in this.focusable:

getFocusable() {
  return [...this.dialog.querySelectorAll('button,[href],choose,textarea,enter:not([type=&quot;hidden&quot;]),[tabindex]:not([tabindex=&quot;-1&quot;])')]

Subsequent, we’ll add a keydown occasion listener, dealing with all our keyboard navigation logic:

this.dialog.addEventListener('keydown', e => {
  if (e.key === 'Enter') {
    if (!this.dialogSupported) e.preventDefault()
    this.parts.settle for.dispatchEvent(new Occasion('click on'))
  if (e.key === 'Escape') this.dialog.dispatchEvent(new Occasion('cancel'))
  if (e.key === 'Tab') {
    const len =  this.focusable.size - 1;
    let index = this.focusable.indexOf(e.goal);
    index = e.shiftKey ? index-1 : index+1;
    if (index < 0) index = len;
    if (index > len) index = 0;

For Enter, we have to forestall the <kind> from submitting in browsers the place the <dialog> component is unsupported. Escape will emit a cancel occasion. Urgent the Tab key will discover the present component within the node checklist of focusable parts, this.focusable, and set concentrate on the following merchandise (or the earlier one should you maintain down the Shift key on the similar time).

Displaying the <dialog>

Now let’s present the dialog! For this, we’d like a small technique that merges an non-obligatory settings object with the default values. On this object — precisely just like the default settings object — we are able to add or change the settings for a selected dialog.

open(settings = {}) {
  const dialog = Object.assign({}, this.settings, settings)
  this.dialog.className = dialog.dialogClass || ''

  /* set innerText of the weather */
  this.parts.settle for.innerText = dialog.settle for
  this.parts.cancel.innerText = dialog.cancel
  this.parts.cancel.hidden = dialog.cancel === ''
  this.parts.message.innerText = dialog.message

  /* If sounds exists, replace `src` */
  this.parts.soundAccept.src = dialog.soundAccept || ''
  this.parts.soundOpen.src = dialog.soundOpen || ''

  /* A goal may be added (from the component invoking the dialog */
  this.parts.goal = dialog.goal || ''

  /* Non-obligatory HTML for customized dialogs */
  this.parts.template.innerHTML = dialog.template || ''

  /* Seize focusable parts */
  this.focusable = this.getFocusable()
  this.hasFormData = this.parts.fieldset.parts.size > 0
  if (dialog.soundOpen) {
  if (this.hasFormData) {
    /* If kind parts exist, concentrate on that first */
  else {
    this.parts.settle for.focus()

Phew! That was quite a lot of code. Now we are able to present the <dialog> component in all browsers. However we nonetheless must mimic the performance that waits for a consumer’s enter after execution, just like the native alert(), affirm(), and immediate() strategies. For that, we’d like a Promise and a brand new technique I’m calling waitForUser():

waitForUser() {
  return new Promise(resolve => {
    this.dialog.addEventListener('cancel', () => { 
    }, { as soon as: true })
    this.parts.settle for.addEventListener('click on', () => {
      let worth = this.hasFormData ? 
        this.collectFormData(new FormData(this.parts.kind)) : true;
      if (this.parts.soundAccept.src) this.parts.soundAccept.play()
    }, { as soon as: true })

This technique returns a Promise. Inside that, we add occasion listeners for “cancel” and “settle for” that both resolve false (cancel), or true (settle for). If formData exists (for customized dialogs or immediate), these might be collected with a helper technique, then returned in an object:

collectFormData(formData) {
  const object = {};
  formData.forEach((worth, key) => {
    if (!Mirror.has(object, key)) {
      object[key] = worth
    if (!Array.isArray(object[key])) {
      object[key] = [object[key]]
  return object

We are able to take away the occasion listeners instantly, utilizing { as soon as: true }.

To maintain it easy, I don’t use reject() however quite merely resolve false.

Hiding the <dialog>

Earlier on, we added occasion listeners for the built-in cancel occasion. We name this occasion when the consumer clicks the “cancel” button or presses the Escape key. The cancel occasion removes the open attribute on the <dialog>, thus hiding it.

The place to :focus?

In our open() technique, we concentrate on both the primary focusable kind area or the “Settle for” button:

if (this.hasFormData) {
else {
  this.parts.settle for.focus()

However is that this appropriate? Within the W3’s “Modal Dialog” instance, that is certainly the case. In Scott Ohara’s instance although, the main target is on the dialog itself — which is smart if the display screen reader ought to learn the textual content we outlined within the aria-labelledby attribute earlier. I’m unsure which is appropriate or finest, but when we wish to use Scott’s technique. we have to add a tabindex="-1" to the <dialog> in our init technique:

this.dialog.tabIndex = -1

Then, within the open() technique, we’ll substitute the main target code with this:


We are able to verify the activeElement (the component that has focus) at any given time in DevTools by clicking the “eye” icon and typing doc.activeElement within the console. Strive tabbing round to see it replace:

Showing the eye icon in DevTools, highlighted in bright green.
Clicking the “eye” icon

Including alert, affirm, and immediate

We’re lastly prepared so as to add alert(), affirm() and immediate() to our Dialog class. These might be small helper strategies that substitute JavaScript dialogs and the unique syntax of these strategies. All of them name the open()technique we created earlier, however with a settings object that matches the way in which we set off the unique strategies.

Let’s examine with the unique syntax.

alert() is often triggered like this:


In our Dialog, we’ll add an alert() technique that’ll mimic this:

/* dialog.alert() */
alert(message, config = { goal: occasion.goal }) {
  const settings = Object.assign({}, config, { cancel: '', message, template: '' })
  return this.waitForUser()

We set cancel and template to empty strings, in order that — even when we had set default values earlier — these is not going to be hidden, and solely message and settle for are proven.

affirm() is often triggered like this:


In our model, much like alert(), we create a customized technique that reveals the message, cancel and settle for gadgets:

/* dialog.affirm() */
affirm(message, config = { goal: occasion.goal }) {
  const settings = Object.assign({}, config, { message, template: '' })
  return this.waitForUser()

immediate() is often triggered like this:

window.immediate(message, default);

Right here, we have to add a template with an <enter> that we’ll wrap in a <label>:

/* dialog.immediate() */
immediate(message, worth, config = { goal: occasion.goal }) {
  const template = `
  <label aria-label="${message}">
    <enter identify="immediate" worth="${worth}">
  const settings = Object.assign({}, config, { message, template })
  return this.waitForUser()

{ goal: occasion.goal } is a reference to the DOM component that calls the strategy. We’ll use that to refocus on that component once we shut the <dialog>, returning the consumer to the place they have been earlier than the dialog was fired.

We ought to check this

It’s time to check and ensure every part is working as anticipated. Let’s create a brand new HTML file, import the category, and create an occasion:

<script sort="module">
  import Dialog from './dialog.js';
  const dialog = new Dialog();

Check out the next use instances one after the other!

/* alert */
dialog.alert('Please refresh your browser')
/* or */
dialog.alert('Please refresh your browser').then((res) => {  console.log(res) })

/* affirm */
dialog.affirm('Do you wish to proceed?').then((res) => { console.log(res) })

/* immediate */
dialog.immediate('The that means of life?', 42).then((res) => { console.log(res) })

Then watch the console as you click on “Settle for” or “Cancel.” Strive once more whereas urgent the Escape or Enter keys as an alternative.


We are able to additionally use the async/await method of doing this. We’re changing JavaScript dialogs much more by mimicking the unique syntax, but it surely requires the wrapping operate to be async, whereas the code inside requires the await key phrase:

doc.getElementById('promptButton').addEventListener('click on', async (e) => {
  const worth = await dialog.immediate('The that means of life?', 42);

Cross-browser styling

We now have a fully-functional cross-browser and display screen reader-friendly HTML dialog component that replaces JavaScript dialogs! We’ve coated lots. However the styling might use quite a lot of love. Let’s make the most of the prevailing data-component and data-ref-attributes so as to add cross-browser styling — no want for added courses or different attributes!

We’ll use the CSS :the place pseudo-selector to maintain our default kinds free from specificity:

:the place([data-component*="dialog"] *) {  
  box-sizing: border-box;
  outline-color: var(--dlg-outline-c, hsl(218, 79.19%, 35%))
:the place([data-component*="dialog"]) {
  --dlg-gap: 1em;
  background: var(--dlg-bg, #fff);
  border: var(--dlg-b, 0);
  border-radius: var(--dlg-bdrs, 0.25em);
  box-shadow: var(--dlg-bxsh, 0px 25px 50px -12px rgba(0, 0, 0, 0.25));
  font-family:var(--dlg-ff, ui-sansserif, system-ui, sans-serif);
  min-inline-size: var(--dlg-mis, auto);
  padding: var(--dlg-p, var(--dlg-gap));
  width: var(--dlg-w, fit-content);
:the place([data-component="no-dialog"]:not([hidden])) {
  show: block;
  inset-block-start: var(--dlg-gap);
  inset-inline-start: 50%;
  place: fastened;
  rework: translateX(-50%);
:the place([data-component*="dialog"] menu) {
  show: flex;
  hole: calc(var(--dlg-gap) / 2);
  justify-content: var(--dlg-menu-jc, flex-end);
  margin: 0;
  padding: 0;
:the place([data-component*="dialog"] menu button) {
  background-color: var(--dlg-button-bgc);
  border: 0;
  border-radius: var(--dlg-bdrs, 0.25em);
  shade: var(--dlg-button-c);
  font-size: var(--dlg-button-fz, 0.8em);
  padding: var(--dlg-button-p, 0.65em 1.5em);
:the place([data-component*="dialog"] [data-ref="accept"]) {
  --dlg-button-bgc: var(--dlg-accept-bgc, hsl(218, 79.19%, 46.08%));
  --dlg-button-c: var(--dlg-accept-c, #fff);
:the place([data-component*="dialog"] [data-ref="cancel"]) {
  --dlg-button-bgc: var(--dlg-cancel-bgc, clear);
  --dlg-button-c: var(--dlg-cancel-c, inherit);
:the place([data-component*="dialog"] [data-ref="fieldset"]) {
  border: 0;
  margin: unset;
  padding: unset;
:the place([data-component*="dialog"] [data-ref="message"]) {
  font-size: var(--dlg-message-fz, 1.25em);
  margin-block-end: var(--dlg-gap);
:the place([data-component*="dialog"] [data-ref="template"]:not(:empty)) {
  margin-block-end: var(--dlg-gap);
  width: 100%;

You’ll be able to fashion these as you’d like, in fact. Right here’s what the above CSS will provide you with:

To overwrite these kinds and use your individual, add a category in dialogClass,

dialogClass: 'customized'

…then add the category in CSS, and replace the CSS customized property values:

.customized {
  --dlg-accept-bgc: hsl(159, 65%, 75%);
  --dlg-accept-c: #000;
  /* and many others. */

A customized dialog instance

What if the usual alert(), affirm() and immediate() strategies we’re mimicking gained’t do the trick on your particular use case? We are able to truly do a bit extra to make the <dialog> extra versatile to cowl greater than the content material, buttons, and performance we’ve coated thus far — and it’s not far more work.

Earlier, I teased the thought of including a sound to the dialog. Let’s do this.

You need to use the template property of the settings object to inject extra HTML. Right here’s a customized instance, invoked from a <button> with id="btnCustom" that triggers a enjoyable little sound from an MP3 file:

doc.getElementById('btnCustom').addEventListener('click on', (e) => {
    settle for: 'Sign up',
    dialogClass: 'customized',
    message: 'Please enter your credentials',
    soundAccept: 'https://assets.yourdomain.com/accept.mp3',
    soundOpen: 'https://assets.yourdomain.com/open.mp3',
    goal: e.goal,
    template: `
    <label>Username<enter sort="textual content" identify="username" worth="admin"></label>
    <label>Password<enter sort="password" identify="password" worth="password"></label>`
  dialog.waitForUser().then((res) => {  console.log(res) })

Dwell demo

Right here’s a Pen with every part we constructed! Open the console, click on the buttons, and mess around with the dialogs, clicking the buttons and utilizing the keyboard to simply accept and cancel.

So, what do you suppose? Is that this a great way to switch JavaScript dialogs with the newer HTML dialog component? Or have you ever tried doing it one other method? Let me know within the feedback!

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