mbeaudru/You-Dont-Need-jQuery

You Don't Need jQuery

Frontend environments evolve rapidly nowadays, modern browsers have already implemented a great deal of DOM/BOM APIs which are good enough. We don't have to learn jQuery from scratch for DOM manipulation or events. In the meantime, thanks to the prevailment of frontend libraries such as React, Angular and Vue, manipulating DOM directly becomes anti-pattern, jQuery has never been less important. This project summarizes most of the jQuery method alternatives in native implementation, with IE 10+ support.

Table of Contents

1. Translations
2. Query Selector
3. CSS & Style
4. DOM Manipulation
5. Ajax
6. Events
7. Utilities
8. Promises
9. Animation
10. Alternatives
11. Browser Support

Translations

• 한국어
• 简体中文
• Bahasa Melayu
• Bahasa Indonesia
• Português(PT-BR)
• Tiếng Việt Nam
• Español
• Русский
• Кыргызча
• Türkçe
• Italiano
• Français
• 日本語

Query Selector

In place of common selectors like class, id or attribute we can use document.querySelector or document.querySelectorAll for substitution. The differences lie in:

• document.querySelector returns the first matched element
• document.querySelectorAll returns all matched elements as NodeList. It can be converted to Array using Array.prototype.slice.call(document.querySelectorAll(selector));
• If there are no elements matched, jQuery and document.querySelectorAll will return [], whereas document.querySelector will return null.

Notice: document.querySelector and document.querySelectorAll are quite SLOW, try to use document.getElementById, document.getElementsByClassName or document.getElementsByTagName if you want to get a performance bonus.

• 1.0 Query by selector

  // jQuery
  $('selector');
  
  // Native
  document.querySelectorAll('selector');
  

• 1.1 Query by class

  // jQuery
  $('.class');
  
  // Native
  document.querySelectorAll('.class');
  
  // or
  document.getElementsByClassName('class');
  

• 1.2 Query by id

  // jQuery
  $('#id');
  
  // Native
  document.querySelector('#id');
  
  // or
  document.getElementById('id');
  

• 1.3 Query by attribute

  // jQuery
  $('a[target=_blank]');
  
  // Native
  document.querySelectorAll('a[target=_blank]');
  

• 1.4 Query in descendents

  // jQuery
  $el.find('li');
  
  // Native
  el.querySelectorAll('li');
  

• 1.5 Sibling/Previous/Next Elements

  • Sibling elements

    // jQuery
    $el.siblings();
    
    // Native
    Array.prototype.filter.call(el.parentNode.children, (child) =>
      child !== el
    );
    

  • Previous elements

    // jQuery
    $el.prev();
    
    // Native
    el.previousElementSibling;
    

  • Next elements

    // jQuery
    $el.next();
    
    // Native
    el.nextElementSibling;
    

• 1.6 Closest

  Return the first matched element by provided selector, traversing from current element to document.

  // jQuery
  $el.closest(selector);
  
  // Native - Only latest, NO IE
  el.closest(selector);
  
  // Native - IE10+
  function closest(el, selector) {
    const matchesSelector = el.matches || el.webkitMatchesSelector || el.mozMatchesSelector || el.msMatchesSelector;
  
    while (el) {
      if (matchesSelector.call(el, selector)) {
        return el;
      } else {
        el = el.parentElement;
      }
    }
    return null;
  }
  

• 1.7 Parents Until

  Get the ancestors of each element in the current set of matched elements, up to but not including the element matched by the selector, DOM node, or jQuery object.

  // jQuery
  $el.parentsUntil(selector, filter);
  
  // Native
  function parentsUntil(el, selector, filter) {
    const result = [];
    const matchesSelector = el.matches || el.webkitMatchesSelector || el.mozMatchesSelector || el.msMatchesSelector;
  
    // match start from parent
    el = el.parentElement;
    while (el && !matchesSelector.call(el, selector)) {
      if (!filter) {
        result.push(el);
      } else {
        if (matchesSelector.call(el, filter)) {
          result.push(el);
        }
      }
      el = el.parentElement;
    }
    return result;
  }
  

• 1.8 Form

  • Input/Textarea

    // jQuery
    $('#my-input').val();
    
    // Native
    document.querySelector('#my-input').value;
    

  • Get index of e.currentTarget between .radio

    // jQuery
    $(e.currentTarget).index('.radio');
    
    // Native
    Array.prototype.indexOf.call(document.querySelectorAll('.radio'), e.currentTarget);
    

• 1.9 Iframe Contents

  $('iframe').contents() returns contentDocument for this specific iframe

  • Iframe contents

    // jQuery
    $iframe.contents();
    
    // Native
    iframe.contentDocument;
    

  • Iframe Query

    // jQuery
    $iframe.contents().find('.css');
    
    // Native
    iframe.contentDocument.querySelectorAll('.css');
    

• 1.10 Get body

  // jQuery
  $('body');
  
  // Native
  document.body;
  

• 1.11 Attribute getter and setter

  • Get an attribute

    // jQuery
    $el.attr('foo');
    
    // Native
    el.getAttribute('foo');
    

  • Set an attribute

    // jQuery, note that this works in memory without change the DOM
    $el.attr('foo', 'bar');
    
    // Native
    el.setAttribute('foo', 'bar');
    

  • Get a data- attribute

    // jQuery
    $el.data('foo');
    
    // Native (use `getAttribute`)
    el.getAttribute('data-foo');
    
    // Native (use `dataset` if only need to support IE 11+)
    el.dataset['foo'];
    

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CSS & Style

• 2.1 CSS

  • Get style

    // jQuery
    $el.css('color');
    
    // Native
    // NOTE: Known bug, will return 'auto' if style value is 'auto'
    const win = el.ownerDocument.defaultView;
    
    // null means not to return pseudo styles
    win.getComputedStyle(el, null).color;
    

  • Set style

    // jQuery
    $el.css({ color: '#f01' });
    
    // Native
    el.style.color = '#f01';
    

  • Get/Set Styles

    Note that if you want to set multiple styles once, you could refer to setStyles method in oui-dom-utils package.

  • Add class

    // jQuery
    $el.addClass(className);
    
    // Native
    el.classList.add(className);
    

  • Remove class

    // jQuery
    $el.removeClass(className);
    
    // Native
    el.classList.remove(className);
    

  • has class

    // jQuery
    $el.hasClass(className);
    
    // Native
    el.classList.contains(className);
    

  • Toggle class

    // jQuery
    $el.toggleClass(className);
    
    // Native
    el.classList.toggle(className);
    

• 2.2 Width & Height

  Width and Height are theoretically identical, take Height as example:

  • Window height

    // window height
    $(window).height();
    
    // with scrollbar
    window.document.documentElement.clientHeight;
    
    // without scrollbar, behaves like jQuery
    window.innerHeight;
    

  • Document height

    // jQuery
    $(document).height();
    
    // Native
    const body = document.body;
    const html = document.documentElement;
    const height = Math.max(
      body.offsetHeight,
      body.scrollHeight,
      html.clientHeight,
      html.offsetHeight,
      html.scrollHeight
    );
    

  • Element height

    // jQuery
    $el.height();
    
    // Native
    function getHeight(el) {
      const styles = window.getComputedStyle(el);
      const height = el.offsetHeight;
      const borderTopWidth = parseFloat(styles.borderTopWidth);
      const borderBottomWidth = parseFloat(styles.borderBottomWidth);
      const paddingTop = parseFloat(styles.paddingTop);
      const paddingBottom = parseFloat(styles.paddingBottom);
      return height - borderBottomWidth - borderTopWidth - paddingTop - paddingBottom;
    }
    
    // accurate to integer（when `border-box`, it's `height`; when `content-box`, it's `height + padding + border`）
    el.clientHeight;
    
    // accurate to decimal（when `border-box`, it's `height`; when `content-box`, it's `height + padding + border`）
    el.getBoundingClientRect().height;
    

• 2.3 Position & Offset

  • Position

    Get the current coordinates of the element relative to the offset parent.

    // jQuery
    $el.position();
    
    // Native
    { left: el.offsetLeft, top: el.offsetTop }
    

  • Offset

    Get the current coordinates of the element relative to the document.

    // jQuery
    $el.offset();
    
    // Native
    function getOffset (el) {
      const box = el.getBoundingClientRect();
    
      return {
        top: box.top + window.pageYOffset - document.documentElement.clientTop,
        left: box.left + window.pageXOffset - document.documentElement.clientLeft
      };
    }
    

• 2.4 Scroll Top

  Get the current vertical position of the scroll bar for the element.

  // jQuery
  $(window).scrollTop();
  
  // Native
  (document.documentElement && document.documentElement.scrollTop) || document.body.scrollTop;
  

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DOM Manipulation

• 3.1 Remove

  Remove the element from the DOM.

  // jQuery
  $el.remove();
  
  // Native
  el.parentNode.removeChild(el);
  

• 3.2 Text

  • Get text

    Get the combined text contents of the element including their descendants,

    // jQuery
    $el.text();
    
    // Native
    el.textContent;
    

  • Set text

    Set the content of the element to the specified text.

    // jQuery
    $el.text(string);
    
    // Native
    el.textContent = string;
    

• 3.3 HTML

  • Get HTML

    // jQuery
    $el.html();
    
    // Native
    el.innerHTML;
    

  • Set HTML

    // jQuery
    $el.html(htmlString);
    
    // Native
    el.innerHTML = htmlString;
    

• 3.4 Append

  Append child element after the last child of parent element

  // jQuery
  $el.append('<div id="container">Hello World</div>');
  
  // Native (HTML string)
  el.insertAdjacentHTML('beforeend', '<div id="container">Hello World</div>');
  
  // Native (Element)
  el.appendChild(newEl);
  

• 3.5 Prepend

  // jQuery
  $el.prepend('<div id="container">Hello World</div>');
  
  // Native (HTML string)
  el.insertAdjacentHTML('afterbegin', '<div id="container">Hello World</div>');
  
  // Native (Element)
  el.insertBefore(newEl, el.firstChild);
  

• 3.6 insertBefore

  Insert a new node before the selected elements

  // jQuery
  $newEl.insertBefore(selector);
  
  // Native (HTML string)
  el.insertAdjacentHTML('beforebegin ', '<div id="container">Hello World</div>');
  
  // Native (Element)
  const el = document.querySelector(selector);
  if (el.parentNode) {
    el.parentNode.insertBefore(newEl, el);
  }
  

• 3.7 insertAfter

  Insert a new node after the selected elements

  // jQuery
  $newEl.insertAfter(selector);
  
  // Native (HTML string)
  el.insertAdjacentHTML('afterend', '<div id="container">Hello World</div>');
  
  // Native (Element)
  const el = document.querySelector(selector);
  if (el.parentNode) {
    el.parentNode.insertBefore(newEl, el.nextSibling);
  }
  

• 3.8 is

  Return true if it matches the query selector

  // jQuery - Notice `is` also work with `function` or `elements` which is not concerned here
  $el.is(selector);
  
  // Native
  el.matches(selector);
  

• 3.9 clone

  Create a deep copy of that element

  // jQuery
  $el.clone();
  
  // Native
  el.cloneNode();
  
  // For Deep clone , set param as `true`
  

• 3.10 empty

  Remove all child nodes

  // jQuery
  $el.empty();
  
  // Native
  el.innerHTML = '';
  

• 3.11 wrap

  Wrap an HTML structure around each element

  // jQuery
  $('.inner').wrap('<div class="wrapper"></div>');
  
  // Native
  Array.prototype.forEach.call(document.querySelectorAll('.inner'), (el) => {
    const wrapper = document.createElement('div');
    wrapper.className = 'wrapper';
    el.parentNode.insertBefore(wrapper, el);
    el.parentNode.removeChild(el);
    wrapper.appendChild(el);
  });
  

• 3.12 unwrap

  Remove the parents of the set of matched elements from the DOM

  // jQuery
  $('.inner').unwrap();
  
  // Native
  Array.prototype.forEach.call(document.querySelectorAll('.inner'), (el) => {
    Array.prototype.forEach.call(el.childNodes, (child) => {
      el.parentNode.insertBefore(child, el);
    });
    el.parentNode.removeChild(el);
  });
  

• 3.13 replaceWith

  Replace each element in the set of matched elements with the provided new content

  // jQuery
  $('.inner').replaceWith('<div class="outer"></div>');
  
  // Native
  Array.prototype.forEach.call(document.querySelectorAll('.inner'), (el) => {
    const outer = document.createElement('div');
    outer.className = 'outer';
    el.parentNode.insertBefore(outer, el);
    el.parentNode.removeChild(el);
  });
  

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Ajax

Fetch API is the new standard to replace XMLHttpRequest to do ajax. It works on Chrome and Firefox, you can use polyfills to make it work on legacy browsers.

Try github/fetch on IE9+ or fetch-ie8 on IE8+, fetch-jsonp to make JSONP requests.

• 4.1 Load data from the server and place the returned HTML into the matched element.

  // jQuery
  $(selector).load(url, completeCallback)
  
  // Native
  fetch(url).then(data => data.text()).then(data => {
    document.querySelector(selector).innerHTML = data
  }).then(completeCallback)
  

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Events

For a complete replacement with namespace and delegation, refer to https://github.com/oneuijs/oui-dom-events

• 5.0 Document ready by DOMContentLoaded

  // jQuery
  $(document).ready(eventHandler);
  
  // Native
  // Check if the DOMContentLoaded has already been completed
  if (document.readyState === 'complete' || document.readyState !== 'loading') {
    eventHandler();
  } else {
    document.addEventListener('DOMContentLoaded', eventHandler);
  }
  

• 5.1 Bind an event with on

  // jQuery
  $el.on(eventName, eventHandler);
  
  // Native
  el.addEventListener(eventName, eventHandler);
  

• 5.2 Unbind an event with off

  // jQuery
  $el.off(eventName, eventHandler);
  
  // Native
  el.removeEventListener(eventName, eventHandler);
  

• 5.3 Trigger

  // jQuery
  $(el).trigger('custom-event', {key1: 'data'});
  
  // Native
  if (window.CustomEvent) {
    const event = new CustomEvent('custom-event', {detail: {key1: 'data'}});
  } else {
    const event = document.createEvent('CustomEvent');
    event.initCustomEvent('custom-event', true, true, {key1: 'data'});
  }
  
  el.dispatchEvent(event);
  

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Utilities

Most of utilities are found by native API. Others advanced functions could be choosed better utilities library focus on consistency and performance. Recommend lodash to replace.

• 6.1 Basic utilities

  • isArray

  Determine whether the argument is an array.

  // jQuery
  $.isArray(array);
  
  // Native
  Array.isArray(array);
  

  • isWindow

  Determine whether the argument is a window.

  // jQuery
  $.isWindow(obj);
  
  // Native
  function isWindow(obj) {
    return obj !== null && obj !== undefined && obj === obj.window;
  }
  

  • inArray

  Search for a specified value within an array and return its index (or -1 if not found).

  // jQuery
  $.inArray(item, array);
  
  // Native
  array.indexOf(item) > -1;
  
  // ES6-way
  array.includes(item);
  

  • isNumeric

  Determine if the argument passed is numerical. Use typeof to decide the type or the type example for better accuracy.

  // jQuery
  $.isNumeric(item);
  
  // Native
  function isNumeric(value) {
    var type = typeof value;
  
    return (type === 'number' || type === 'string') && !Number.isNaN(value - Number.parseFloat(value));
  }
  

  • isFunction

  Determine if the argument passed is a JavaScript function object.

  // jQuery
  $.isFunction(item);
  
  // Native
  function isFunction(item) {
    if (typeof item === 'function') {
      return true;
    }
    var type = Object.prototype.toString(item);
    return type === '[object Function]' || type === '[object GeneratorFunction]';
  }
  

  • isEmptyObject

  Check to see if an object is empty (contains no enumerable properties).

  // jQuery
  $.isEmptyObject(obj);
  
  // Native
  function isEmptyObject(obj) {
    return Object.keys(obj).length === 0;
  }
  

  • isPlainObject

  Check to see if an object is a plain object (created using “{}” or “new Object”).

  // jQuery
  $.isPlainObject(obj);
  
  // Native
  function isPlainObject(obj) {
    if (typeof (obj) !== 'object' || obj.nodeType || obj !== null && obj !== undefined && obj === obj.window) {
      return false;
    }
  
    if (obj.constructor &&
        !Object.prototype.hasOwnProperty.call(obj.constructor.prototype, 'isPrototypeOf')) {
      return false;
    }
  
    return true;
  }
  

  • extend

  Merge the contents of two or more objects together into the first object. object.assign is ES6 API, and you could use polyfill also.

  // jQuery
  $.extend({}, defaultOpts, opts);
  
  // Native
  Object.assign({}, defaultOpts, opts);
  

  • trim

  Remove the white-space from the beginning and end of a string.

  // jQuery
  $.trim(string);
  
  // Native
  string.trim();
  

  • map

  Translate all items in an array or object to new array of items.

  // jQuery
  $.map(array, (value, index) => {
  });
  
  // Native
  array.map((value, index) => {
  });
  

  • each

  A generic iterator function, which can be used to seamlessly iterate over both objects and arrays.

  // jQuery
  $.each(array, (index, value) => {
  });
  
  // Native
  array.forEach((value, index) => {
  });
  

  • grep

  Finds the elements of an array which satisfy a filter function.

  // jQuery
  $.grep(array, (value, index) => {
  });
  
  // Native
  array.filter((value, index) => {
  });
  

  • type

  Determine the internal JavaScript [Class] of an object.

  // jQuery
  $.type(obj);
  
  // Native
  function type(item) {
    const reTypeOf = /(?:^\[object\s(.*?)\]$)/;
    return Object.prototype.toString.call(item)
      .replace(reTypeOf, '$1')
      .toLowerCase();
  }
  

  • merge

  Merge the contents of two arrays together into the first array.

  // jQuery
  $.merge(array1, array2);
  
  // Native
  // But concat function doesn't remove duplicate items.
  function merge(...args) {
    return [].concat(...args)
  }
  

  • now

  Return a number representing the current time.

  // jQuery
  $.now();
  
  // Native
  Date.now();
  

  • proxy

  Takes a function and returns a new one that will always have a particular context.

  // jQuery
  $.proxy(fn, context);
  
  // Native
  fn.bind(context);
  

  • makeArray

  Convert an array-like object into a true JavaScript array.

  // jQuery
  $.makeArray(arrayLike);
  
  // Native
  Array.prototype.slice.call(arrayLike);
  
  // ES6-way
  Array.from(arrayLike);
  

• 6.2 Contains

  Check to see if a DOM element is a descendant of another DOM element.

  // jQuery
  $.contains(el, child);
  
  // Native
  el !== child && el.contains(child);
  

• 6.3 Globaleval

  Execute some JavaScript code globally.

  // jQuery
  $.globaleval(code);
  
  // Native
  function Globaleval(code) {
    const script = document.createElement('script');
    script.text = code;
  
    document.head.appendChild(script).parentNode.removeChild(script);
  }
  
  // Use eval, but context of eval is current, context of $.Globaleval is global.
  eval(code);
  

• 6.4 parse

  • parseHTML

  Parses a string into an array of DOM nodes.

  // jQuery
  $.parseHTML(htmlString);
  
  // Native
  function parseHTML(string) {
    const context = document.implementation.createHTMLDocument();
  
    // Set the base href for the created document so any parsed elements with URLs
    // are based on the document's URL
    const base = context.createElement('base');
    base.href = document.location.href;
    context.head.appendChild(base);
  
    context.body.innerHTML = string;
    return context.body.children;
  }
  

  • parseJSON

  Takes a well-formed JSON string and returns the resulting JavaScript value.

  // jQuery
  $.parseJSON(str);
  
  // Native
  JSON.parse(str);
  

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Promises

A promise represents the eventual result of an asynchronous operation. jQuery has its own way to handle promises. Native JavaScript implements a thin and minimal API to handle promises according to the Promises/A+ specification.

• 7.1 done, fail, always

  done is called when promise is resolved, fail is called when promise is rejected, always is called when promise is either resolved or rejected.

  // jQuery
  $promise.done(doneCallback).fail(failCallback).always(alwaysCallback)
  
  // Native
  promise.then(doneCallback, failCallback).then(alwaysCallback, alwaysCallback)
  

• 7.2 when

  when is used to handle multiple promises. It will resolve when all promises are resolved, and reject if either one is rejected.

  // jQuery
  $.when($promise1, $promise2).done((promise1Result, promise2Result) => {
  });
  
  // Native
  Promise.all([$promise1, $promise2]).then([promise1Result, promise2Result] => {});
  

• 7.3 Deferred

  Deferred is a way to create promises.

  // jQuery
  function asyncFunc() {
    const defer = new $.Deferred();
    setTimeout(() => {
      if(true) {
        defer.resolve('some_value_computed_asynchronously');
      } else {
        defer.reject('failed');
      }
    }, 1000);
  
    return defer.promise();
  }
  
  // Native
  function asyncFunc() {
    return new Promise((resolve, reject) => {
      setTimeout(() => {
        if (true) {
          resolve('some_value_computed_asynchronously');
        } else {
          reject('failed');
        }
      }, 1000);
    });
  }
  
  // Deferred way
  function defer() {
    const deferred = {};
    const promise = new Promise((resolve, reject) => {
      deferred.resolve = resolve;
      deferred.reject = reject;
    });
  
    deferred.promise = () => {
      return promise;
    };
  
    return deferred;
  }
  
  function asyncFunc() {
    const defer = defer();
    setTimeout(() => {
      if(true) {
        defer.resolve('some_value_computed_asynchronously');
      } else {
        defer.reject('failed');
      }
    }, 1000);
  
    return defer.promise();
  }
  

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Animation

• 8.1 Show & Hide

  // jQuery
  $el.show();
  $el.hide();
  
  // Native
  // More detail about show method, please refer to https://github.com/oneuijs/oui-dom-utils/blob/master/src/index.js#L363
  el.style.display = ''|'inline'|'inline-block'|'inline-table'|'block';
  el.style.display = 'none';
  

• 8.2 Toggle

  Display or hide the element.

  // jQuery
  $el.toggle();
  
  // Native
  if (el.ownerDocument.defaultView.getComputedStyle(el, null).display === 'none') {
    el.style.display = ''|'inline'|'inline-block'|'inline-table'|'block';
  } else {
    el.style.display = 'none';
  }
  

• 8.3 FadeIn & FadeOut

  // jQuery
  $el.fadeIn(3000);
  $el.fadeOut(3000);
  
  // Native
  el.style.transition = 'opacity 3s';
  // fadeIn
  el.style.opacity = '1';
  // fadeOut
  el.style.opacity = '0';
  

• 8.4 FadeTo

  Adjust the opacity of the element.

  // jQuery
  $el.fadeTo('slow',0.15);
  // Native
  el.style.transition = 'opacity 3s'; // assume 'slow' equals 3 seconds
  el.style.opacity = '0.15';
  

• 8.5 FadeToggle

  Display or hide the element by animating their opacity.

  // jQuery
  $el.fadeToggle();
  
  // Native
  el.style.transition = 'opacity 3s';
  const { opacity } = el.ownerDocument.defaultView.getComputedStyle(el, null);
  if (opacity === '1') {
    el.style.opacity = '0';
  } else {
    el.style.opacity = '1';
  }
  

• 8.6 SlideUp & SlideDown

  // jQuery
  $el.slideUp();
  $el.slideDown();
  
  // Native
  const originHeight = '100px';
  el.style.transition = 'height 3s';
  // slideUp
  el.style.height = '0px';
  // slideDown
  el.style.height = originHeight;
  

• 8.7 SlideToggle

  Display or hide the element with a sliding motion.

  // jQuery
  $el.slideToggle();
  
  // Native
  const originHeight = '100px';
  el.style.transition = 'height 3s';
  const { height } = el.ownerDocument.defaultView.getComputedStyle(el, null);
  if (parseInt(height, 10) === 0) {
    el.style.height = originHeight;
  }
  else {
   el.style.height = '0px';
  }
  

• 8.8 Animate

  Perform a custom animation of a set of CSS properties.

  // jQuery
  $el.animate({ params }, speed);
  
  // Native
  el.style.transition = 'all ' + speed;
  Object.keys(params).forEach((key) =>
    el.style[key] = params[key];
  )
  

Alternatives

• You Might Not Need jQuery - Examples of how to do common event, element, ajax etc with plain javascript.
• npm-dom and webmodules - Organizations you can find individual DOM modules on NPM

Browser Support

License

MIT