Demo.prototype.displayAllUsers = function()

in fcm-notifications/public/main.js [80:136]
46 lines of code
4 McCabe index (conditional complexity)

Demo.prototype.displayAllUsers = function() {
  var usersRef = firebase.database().ref('users');
  usersRef.on('child_added', function(snapshot) {
    // Create the HTML for a user.
    var photoURL = snapshot.val().photoURL;
    var displayName = snapshot.val().displayName;
    var uid = snapshot.key;
    var userTemplate =
        '<div class="demo-user-container">' +
        '  <img class="demo-profile-pic" src="' + photoURL + '">' +
        '  <span class="demo-name">' + displayName + '</span>' +
        '  <span class="demo-notifications-enabled">(notifications enabled)</span>' +
        '  <label class="mdl-switch mdl-js-switch mdl-js-ripple-effect" for="demo-follow-switch-' + uid + '">' +
        '    <input type="checkbox" id="demo-follow-switch-' + uid + '" class="mdl-switch__input">' +
        '    <span class="mdl-switch__label">Follow</span>' +
        '  </label>' +
        '</div>';

    // Create the DOM element from the HTML.
    var div = document.createElement('div');
    div.innerHTML = userTemplate;
    var userElement = div.firstChild;
    this.usersContainer.appendChild(userElement);

    // Activate the Material Design Lite Switch element.
    var materialSwitchContainer = userElement.getElementsByClassName('mdl-switch')[0];
    if (componentHandler) {
      componentHandler.upgradeElement(materialSwitchContainer);
    }

    // Check if the user has notifications enabled and show a flag if he has.
    var notificationEnabledElement = userElement.getElementsByClassName('demo-notifications-enabled')[0];
    var notificationsEnabledRef = snapshot.ref.child('notificationTokens');
    notificationsEnabledRef.on('value', function(notificationsEnabledSnapshot) {
      notificationEnabledElement.style.display = notificationsEnabledSnapshot.hasChildren() ? 'inline' : 'none';
    });
    this.listeners.push(notificationsEnabledRef);

    // Listen for the Switch state from the Realtime database.
    var switchElement = document.getElementById('demo-follow-switch-' + uid);
    var followUserRef = firebase.database().ref('followers/' + uid + '/' + this.currentUid);
    this.listeners.push(followUserRef);
    followUserRef.on('value', function(followSnapshot) {
      switchElement.checked = !!followSnapshot.val();
      if (materialSwitchContainer.MaterialSwitch) {
        materialSwitchContainer.MaterialSwitch.checkDisabled();
        materialSwitchContainer.MaterialSwitch.checkToggleState();
      }
    });

    // Listen for switch state changes from the user.
    switchElement.addEventListener('change', function() {
      followUserRef.set(!!switchElement.checked);
    });
  }.bind(this));
  this.listeners.push(usersRef);
};