Which HTML elements can receive focus?

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死守一世寂寞
死守一世寂寞 2020-11-22 00:20

I\'m looking for a definitive list of HTML elements which are allowed to take focus, i.e. which elements will be put into focus when focus() is called on them?<

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  • 2020-11-22 00:59

    There isn't a definite list, it's up to the browser. The only standard we have is DOM Level 2 HTML, according to which the only elements that have a focus() method are HTMLInputElement, HTMLSelectElement, HTMLTextAreaElement and HTMLAnchorElement. This notably omits HTMLButtonElement and HTMLAreaElement.

    Today's browsers define focus() on HTMLElement, but an element won't actually take focus unless it's one of:

    • HTMLAnchorElement/HTMLAreaElement with an href
    • HTMLInputElement/HTMLSelectElement/HTMLTextAreaElement/HTMLButtonElement but not with disabled (IE actually gives you an error if you try), and file uploads have unusual behaviour for security reasons
    • HTMLIFrameElement (though focusing it doesn't do anything useful). Other embedding elements also, maybe, I haven't tested them all.
    • Any element with a tabindex

    There are likely to be other subtle exceptions and additions to this behaviour depending on browser.

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  • 2020-11-22 01:08

    The ally.js accessibility library provides an unofficial, test-based list here:

    https://allyjs.io/data-tables/focusable.html

    (NB: Their page doesn't say how often tests were performed.)

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  • 2020-11-22 01:11

    Here I have a CSS-selector based on bobince's answer to select any focusable HTML element:

      a[href]:not([tabindex='-1']),
      area[href]:not([tabindex='-1']),
      input:not([disabled]):not([tabindex='-1']),
      select:not([disabled]):not([tabindex='-1']),
      textarea:not([disabled]):not([tabindex='-1']),
      button:not([disabled]):not([tabindex='-1']),
      iframe:not([tabindex='-1']),
      [tabindex]:not([tabindex='-1']),
      [contentEditable=true]:not([tabindex='-1'])
      {
          /* your CSS for focusable elements goes here */
      }
    

    or a little more beautiful in SASS:

    a[href],
    area[href],
    input:not([disabled]),
    select:not([disabled]),
    textarea:not([disabled]),
    button:not([disabled]),
    iframe,
    [tabindex],
    [contentEditable=true]
    {
        &:not([tabindex='-1'])
        {
            /* your SCSS for focusable elements goes here */
        }
    }
    

    I've added it as an answer, because that was, what I was looking for, when Google redirected me to this Stackoverflow question.

    EDIT: There is one more selector, which is focusable:

    [contentEditable=true]
    

    However, this is used very rarely.

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  • 2020-11-22 01:13

    Maybe this one can help:

    function focus(el){
    	el.focus();
    	return el==document.activeElement;
    }

    return value: true = success, false = failed

    Reff: https://developer.mozilla.org/en-US/docs/Web/API/DocumentOrShadowRoot/activeElement https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/focus

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  • 2020-11-22 01:22
    $focusable:
      'a[href]',
      'area[href]',
      'button',
      'details',
      'input',
      'iframe',
      'select',
      'textarea',
    
      // these are actually case sensitive but i'm not listing out all the possible variants
      '[contentEditable=""]',
      '[contentEditable="true"]',
      '[contentEditable="TRUE"]',
    
      '[tabindex]:not([tabindex^="-"])',
      ':not([disabled])';
    

    I'm creating a SCSS list of all focusable elements and I thought this might help someone due to this question's Google rank.

    A few things to note:

    • I changed :not([tabindex="-1"]) to :not([tabindex^="-"]) because it's perfectly plausible to generate -2 somehow. Better safe than sorry right?
    • Adding :not([tabindex^="-"]) to all the other focusable selectors is completely pointless. When using [tabindex]:not([tabindex^="-"]) it already includes all elements that you'd be negating with :not!
    • I included :not([disabled]) because disabled elements can never be focusable. So again it's useless to add it to every single element.
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