Firebase: Remove the last item in a list. This snippet removes only the last item in a list.

firebase_pop.js

// Run test @ http://jsfiddle.net/NRJ4d/
 
function makeList(ref) {
  var fruits = ["banana", "apple", "grape", "orange"];
  for (var i = 0; i < fruits.length; i++) {
    ref.push(fruits[i]);
  }
}

function getLastFromList(ref, onComplete) {
  ref.limit(1).once("child_added", function(s) {
    onComplete(s);
  });
}

function pop(ref, onComplete) {
  // Remove last entry of the list
    getLastFromList(ref, function(s) {
      if (s.typeOf === "object") {
        // jQuery version
        // var val = $.extend(true, {}, s);
        // Pure javascript version
          var val = JSON.parse(JSON.stringify(s));
        } else {
          var val = s.val();
        }
        s.ref().remove(onComplete(val));
    });
}

// Running this should popup an alert with "orange"
// and "orange" should be removed from the list
function go() {
  var testRef = new Firebase("https://example.firebaseIO-demo.com/");
  makeList(testRef);
  pop(testRef, function(last_item) {
    alert(last_item);
  });
}