Supporting IE 8

Why would anyone care about IE8 ?

Well sometime we have to if our clients is still on it, and yes in 2015, there are groups in the federal business that still only use IE 8.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/slice

Problem: Object doesn't support property or method 'preventDefault'

Basic solution #1
Replace
event.preventDefault()
with:
if (event.preventDefault) { event.preventDefault(); } else { event.returnValue = false; }

More elegant solution #2

Using a library to handle event handler will usually take care to shim all your event with a preventDefault() function. For example the most basic Javascript toolbox will take care of it when attaching your event. jQuery will also shim events so you don't have to worry about it.

Problem: The "onchange" event does not fire for checkboxes and radios

Solution #1 - Cry a lot and pretend it's not happening

Solution #2 (preferred) - Do this hack :

Problem: The UI renders additional blocks

Wrong (for IE8):

for (var i in streamsList) {
div = document.createElement("div");
(...)
}

Good:
for (var i=0; i<streamsList.length; i++;) {
div = document.createElement("div");
(...)
}

Problem: Object doesn't support property or method 'indexOf'

This is a known issue and not your fault. IE8 plainly doesn't support indexOf for Array type.

Use the following polyfill from MDN :

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/indexOf#Compatibility

// Production steps of ECMA-262, Edition 5, 15.4.4.14
// Reference: http://es5.github.io/#x15.4.4.14
if (!Array.prototype.indexOf) {
  Array.prototype.indexOf = function(searchElement, fromIndex) {

    var k;

    // 1. Let O be the result of calling ToObject passing
    //    the this value as the argument.
    if (this == null) {
      throw new TypeError('"this" is null or not defined');
    }

    var O = Object(this);

    // 2. Let lenValue be the result of calling the Get
    //    internal method of O with the argument "length".
    // 3. Let len be ToUint32(lenValue).
    var len = O.length >>> 0;

    // 4. If len is 0, return -1.
    if (len === 0) {
      return -1;
    }

    // 5. If argument fromIndex was passed let n be
    //    ToInteger(fromIndex); else let n be 0.
    var n = +fromIndex || 0;

    if (Math.abs(n) === Infinity) {
      n = 0;
    }

    // 6. If n >= len, return -1.
    if (n >= len) {
      return -1;
    }

    // 7. If n >= 0, then Let k be n.
    // 8. Else, n<0, Let k be len - abs(n).
    //    If k is less than 0, then let k be 0.
    k = Math.max(n >= 0 ? n : len - Math.abs(n), 0);

    // 9. Repeat, while k < len
    while (k < len) {
      // a. Let Pk be ToString(k).
      //   This is implicit for LHS operands of the in operator
      // b. Let kPresent be the result of calling the
      //    HasProperty internal method of O with argument Pk.
      //   This step can be combined with c
      // c. If kPresent is true, then
      //    i.  Let elementK be the result of calling the Get
      //        internal method of O with the argument ToString(k).
      //   ii.  Let same be the result of applying the
      //        Strict Equality Comparison Algorithm to
      //        searchElement and elementK.
      //  iii.  If same is true, return k.
      if (k in O && O[k] === searchElement) {
        return k;
      }
      k++;
    }
    return -1;
  };
}