Input Range

no-jQuery cross-browser desktop-and-mobile ability to consistently respond to range/slider interactions

by borisjavier

HTML

<input type="range"/>
<p id="rangeValPar">range value: 50</p>
<table>
  <tr><th>row</th><th>event type                     </th><th>number of events    </th><tr>
  <tr><td>A</td><td>standard "change" events         </td><td id="numChgEvtsCell">0</td></tr>
  <tr><td>B</td><td>standard "input" events          </td><td id="numInpEvtsCell">0</td></tr>
  <tr><td>C</td><td>new custom "onRangeChange" events</td><td id="numCusEvtsCell">0</td></tr>
</table>

CSS

table {
  border-collapse: collapse;  
}
th, td {
  text-align: left;
  border: solid black 1px;
  padding: 5px 15px;
}

JavaScript

// main function for emulating IE11's "change" event:

function onRangeChange(rangeInputElmt, listener) {

  var inputEvtHasNeverFired = true;

  var rangeValue = {current: undefined, mostRecent: undefined};
  
  rangeInputElmt.addEventListener("input", function(evt) {
    inputEvtHasNeverFired = false;
    rangeValue.current = evt.target.value;
    if (rangeValue.current !== rangeValue.mostRecent) {
      listener(evt);
    }
    rangeValue.mostRecent = rangeValue.current;
  });

  rangeInputElmt.addEventListener("change", function(evt) {
    if (inputEvtHasNeverFired) {
      listener(evt);
    }
  }); 

}

// example usage:

var myRangeInputElmt = document.querySelector("input"          );
var myRangeValPar    = document.querySelector("#rangeValPar"   );
var myNumChgEvtsCell = document.querySelector("#numChgEvtsCell");
var myNumInpEvtsCell = document.querySelector("#numInpEvtsCell");
var myNumCusEvtsCell = document.querySelector("#numCusEvtsCell");

var myNumEvts = {input: 0, change: 0, custom: 0};

var myUpdate = function() {
  myNumChgEvtsCell.innerHTML = myNumEvts["change"];
  myNumInpEvtsCell.innerHTML = myNumEvts["input" ];
  myNumCusEvtsCell.innerHTML = myNumEvts["custom"];
};

["input", "change"].forEach(function(myEvtType) {
  myRangeInputElmt.addEventListener(myEvtType,  function() {
    myNumEvts[myEvtType] += 1;
    myUpdate();
  });
});

var myListener = function(myEvt) {
  myNumEvts["custom"] += 1;
  myRangeValPar.innerHTML = "range value: " + myEvt.target.value;
  myUpdate();
};

onRangeChange(myRangeInputElmt, myListener);