function Popper()

in js/popper.js [2477:2541]


  function Popper(reference, popper) {
    var _this = this;

    var options = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : {};
    classCallCheck(this, Popper);

    this.scheduleUpdate = function () {
      return requestAnimationFrame(_this.update);
    };

    // make update() debounced, so that it only runs at most once-per-tick
    this.update = debounce(this.update.bind(this));

    // with {} we create a new object with the options inside it
    this.options = _extends({}, Popper.Defaults, options);

    // init state
    this.state = {
      isDestroyed: false,
      isCreated: false,
      scrollParents: []
    };

    // get reference and popper elements (allow jQuery wrappers)
    this.reference = reference && reference.jquery ? reference[0] : reference;
    this.popper = popper && popper.jquery ? popper[0] : popper;

    // Deep merge modifiers options
    this.options.modifiers = {};
    Object.keys(_extends({}, Popper.Defaults.modifiers, options.modifiers)).forEach(function (name) {
      _this.options.modifiers[name] = _extends({}, Popper.Defaults.modifiers[name] || {}, options.modifiers ? options.modifiers[name] : {});
    });

    // Refactoring modifiers' list (Object => Array)
    this.modifiers = Object.keys(this.options.modifiers).map(function (name) {
      return _extends({
        name: name
      }, _this.options.modifiers[name]);
    })
    // sort the modifiers by order
    .sort(function (a, b) {
      return a.order - b.order;
    });

    // modifiers have the ability to execute arbitrary code when Popper.js get inited
    // such code is executed in the same order of its modifier
    // they could add new properties to their options configuration
    // BE AWARE: don't add options to `options.modifiers.name` but to `modifierOptions`!
    this.modifiers.forEach(function (modifierOptions) {
      if (modifierOptions.enabled && isFunction(modifierOptions.onLoad)) {
        modifierOptions.onLoad(_this.reference, _this.popper, _this.options, modifierOptions, _this.state);
      }
    });

    // fire the first update to position the popper in the right place
    this.update();

    var eventsEnabled = this.options.eventsEnabled;
    if (eventsEnabled) {
      // setup event listeners, they will take care of update the position in specific situations
      this.enableEventListeners();
    }

    this.state.eventsEnabled = eventsEnabled;
  }