nguyenbathanh / You-Dont-Need-jQuery

Examples of how to do query, style, dom, ajax, event etc like jQuery with plain javascript.

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

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 [].slice.call(document.querySelectorAll(selector) || []);
  • If no elements matched, jQuery would return [] whereas the DOM API will return null. Pay attention to Null Pointer Exception. You can also use || to set default value if not found, like document.querySelectorAll(selector) || []

Notice: document.querySelector and document.querySelectorAll are quite SLOW, try to use 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 Find sth.

    • Find nodes

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

      // jQuery
      $('body');
      
      // Native
      document.body;
    • Find Attribute

      // jQuery
      $el.attr('foo');
      
      // Native
      e.getAttribute('foo');
    • Find data attribute

      // jQuery
      $el.data('foo');
      
      // Native
      // using getAttribute
      el.getAttribute('data-foo');
      // you can also use `dataset` if only need to support IE 11+
      el.dataset['foo'];
  • 1.5 Sibling/Previous/Next Elements

    • Sibling elements

      // jQuery
      $el.siblings();
      
      // Native
      [].filter.call(el.parentNode.children, function(child) {
        return 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(queryString);
    
    // Native
    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
      [].indexOf.call(document.querySelectAll('.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');

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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 return pseudo styles
      win.getComputedStyle(el, null).color;
    • Set style

      // jQuery
      $el.css({ color: "#ff0011" });
      
      // Native
      el.style.color = '#ff0011';
    • 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();
      // without scrollbar, behaves like jQuery
      window.document.documentElement.clientHeight;
      // with scrollbar
      window.innerHeight;
    • Document height

      // jQuery
      $(document).height();
      
      // Native
      document.documentElement.scrollHeight;
    • Element height

      // jQuery
      $el.height();
      
      // Native
      function getHeight(el) {
        const styles = this.getComputedStyles(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

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

      // 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

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

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DOM Manipulation

  • 3.1 Remove

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

    • Get text

      // jQuery
      $el.text();
      
      // Native
      el.textContent;
    • Set 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</div>");
    
    // Native
    let newEl = document.createElement('div');
    newEl.setAttribute('id', 'container');
    newEl.innerHTML = 'hello';
    el.appendChild(newEl);
  • 3.5 Prepend

    // jQuery
    $el.prepend("<div id='container'>hello</div>");
    
    // Native
    let newEl = document.createElement('div');
    newEl.setAttribute('id', 'container');
    newEl.innerHTML = 'hello';
    el.insertBefore(newEl, el.firstChild);
  • 3.6 insertBefore

    Insert a new node before the selected elements

    // jQuery
    $newEl.insertBefore(queryString);
    
    // Native
    const target = document.querySelector(queryString);
    target.parentNode.insertBefore(newEl, target);
  • 3.7 insertAfter

    Insert a new node after the selected elements

    // jQuery
    $newEl.insertAfter(queryString);
    
    // Native
    const target = document.querySelector(queryString);
    target.parentNode.insertBefore(newEl, target.nextSibling);

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Ajax

Replace with fetch and fetch-jsonp

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Events

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

  • 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

  • 6.1 isArray

    // jQuery
    $.isArray(range);
    
    // Native
    Array.isArray(range);
  • 6.2 Trim

    // jQuery
    $.trim(string);
    
    // Native
    string.trim();
  • 6.3 Object Assign

    Extend, use object.assign polyfill https://github.com/ljharb/object.assign

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

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

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Alternatives

Translations

Browser Support

Chrome Firefox IE Opera Safari
Latest ✔ Latest ✔ 10+ ✔ Latest ✔ 6.1+ ✔

License

MIT

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Examples of how to do query, style, dom, ajax, event etc like jQuery with plain javascript.

License:MIT License


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