Howto Trigger Input Event Programmatically on Input Text Field

Howto trigger input event programmatically on input text field?

Try this to manually dispatch the event, see EventTarget.dispatchEvent():

inputField.dispatchEvent(new Event("input"))

How do I programmatically trigger an “input” event without jQuery?

The proper way to trigger an event with plain JavaScript, would be to create an Event object, and dispatch it

var event = new Event('input', {
    bubbles: true,
    cancelable: true,
});
  
element.dispatchEvent(event);

Or, as a simple one-liner:

element.dispatchEvent(new Event('input', {bubbles:true}));

FIDDLE

This is not supported in IE, for that the old-fashioned way still has to be used

var event = document.createEvent('Event');
event.initEvent('input', true, true);

elem.dispatchEvent(event);

Trigger action on programmatic change to an input value

if the only problem with your solution is breaking of change event on value set. thn you can fire that event manually on set. (But this wont monitor set in case a user makes a change to the input via browser -- see edit bellow)

<html>
  <body>
    <input type='hidden' id='myInput' />
    <input type='text' id='myInputVisible' />
    <input type='button' value='Test' onclick='return testSet();'/>
    <script>
      //hidden input which your API will be changing
      var myInput=document.getElementById("myInput");
      //visible input for the users
      var myInputVisible=document.getElementById("myInputVisible");
      //property mutation for hidden input
      Object.defineProperty(myInput,"value",{
        get:function(){
          return this.getAttribute("value");
        },
        set:function(val){
          console.log("set");

          //update value of myInputVisible on myInput set
          myInputVisible.value = val;

          // handle value change here
          this.setAttribute("value",val);

          //fire the event
          if ("createEvent" in document) {  // Modern browsers
            var evt = document.createEvent("HTMLEvents");
            evt.initEvent("change", true, false);
            myInput.dispatchEvent(evt);
          }
          else {  // IE 8 and below
            var evt = document.createEventObject();
            myInput.fireEvent("onchange", evt);
          }
        }
      });  

      //listen for visible input changes and update hidden
      myInputVisible.onchange = function(e){
        myInput.value = myInputVisible.value;
      };

      //this is whatever custom event handler you wish to use
      //it will catch both the programmatic changes (done on myInput directly)
      //and user's changes (done on myInputVisible)
      myInput.onchange = function(e){
        console.log(myInput.value);
      };

      //test method to demonstrate programmatic changes 
      function testSet(){
        myInput.value=Math.floor((Math.random()*100000)+1);
      }
    </script>
  </body>
</html>

How to programmatically click on a text input using JQuery?

Thank you all for your help, but I somehow found the solution by randomly checking everything I saw:

$("#m").trigger("focus");

Use focus instead of click

Howto Trigger Input Event Programmatically on Input Text Field