How to advance to the next form input when the current input has a value?

Question

I am having a form with lots of entries. I would like to change my focus to the next textbox, once I entered the value in the current textbox. and want to continue this proc

Answer 1

This should work. Working with and without tabindex.

var currentlyFocused = undefined;
var tabableElements = undefined;

/**
 * Compare function for element sort
 * @param {string | null} a
 * @param {string | null} b
 * @param {boolean} asc
 */
function sortCompare(a, b, asc = true) {
  let result = null;
  if (a == null) result = 1;
  else if (b == null) result = -1;
  else if (parseInt(a) > parseInt(b)) result = 1;
  else if (parseInt(a) < parseInt(b)) result = -1;
  else result = 0;
  return result * (asc ? 1 : -1);
}

/**
 * When an element is focused assign it to the currentlyFocused variable
 * @param {Element} element
 */
function registerOnElementFocus(element) {
  element.addEventListener("focus", function(el) {
    currentlyFocused = el.srcElement;
  });
}

/**
 * Tab Trigger
 */
function onTabClick() {
  //Select currently focused element
  let currentIndex;
  tabableElements.forEach((el, idx) => {
    //return if no element is focused
    if (!currentlyFocused) return;
    if (currentlyFocused.isEqualNode(el)) {
      //assign current index and return
      currentIndex = idx;
      return;
    }
  });
  //if theres no focused element or the current focused element is last start over
  let lastIndex = tabableElements.length - 1;
  let nextElementidx = currentIndex === undefined || currentIndex == lastIndex ? 0 : currentIndex + 1;
  //Focus
  currentlyFocused = tabableElements[nextElementidx];
  currentlyFocused.focus();
}
/**
 * Init must be run after all elements are loadead in the dom
 */
function init() {
  //Get all tab-able elements
  let nodeList = document.querySelectorAll("input, button, a, area, object, select, textarea, [tabindex]");
  //To array for easier manipulation
  tabableElements = Array.prototype.slice.call(nodeList, 0);
  //Correcting tabindexes to ensure correct order
  tabableElements.forEach((el, idx, list) => {
    let tabindex = el.getAttribute("tabindex");
    //-1 tabindex will not receive focus
    if (tabindex == -1) list.splice(idx, 1);
    //null or 0 tabindex in normal source order
    else if (tabindex == null || tabindex == 0) {
      list[idx].setAttribute("tabindex", 9999 + idx);
    }
  });
  //sort elements by their tabindex in ascending order
  tabableElements.sort((elementA, elementB) => sortCompare(elementA.getAttribute("tabindex"), elementB.getAttribute("tabindex")));
  //register focus event to elements
  tabableElements.forEach(el => registerOnElementFocus(el));
}

  
  
  

  
  

  



  

    
Virtual Tab Demo
    

      

        Tab!
      
      

      

      Button1
      Button2
      

      

      text
      

      password
      

      number
      

      checkbox
      

      radio
      

      

      Button3
      Button4
      

      

      
        Volvo
        Saab
        Mercedes
        Audi
      
      

      
 textarea
      

      
        

        

        Focus other elements.