bootstrap-vue/es/mixins/listen-on-root.js

BootstrapVue provides one of the most comprehensive implementations of Bootstrap 4 components and grid system for Vue.js and with extensive and automated WAI-ARIA accessibility markup.

function _toConsumableArray(arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) { arr2[i] = arr[i]; } return arr2; } else { return Array.from(arr); } }

import { isArray } from '../utils/array';
/**
 * Issue #569: collapse::toggle::state triggered too many times
 * @link https://github.com/bootstrap-vue/bootstrap-vue/issues/569
 */

var BVRL = '__BV_root_listeners__';

export default {
  methods: {
    /**
         * Safely register event listeners on the root Vue node.
         * While Vue automatically removes listeners for individual components,
         * when a component registers a listener on root and is destroyed,
         * this orphans a callback because the node is gone,
         * but the root does not clear the callback.
         *
         * This adds a non-reactive prop to a vm on the fly
         * in order to avoid object observation and its performance costs
         * to something that needs no reactivity.
         * It should be highly unlikely there are any naming collisions.
         * @param {string} event
         * @param {function} callback
         * @chainable
         */
    listenOnRoot: function listenOnRoot(event, callback) {
      if (!this[BVRL] || !isArray(this[BVRL])) {
        this[BVRL] = [];
      }
      this[BVRL].push({ event: event, callback: callback });
      this.$root.$on(event, callback);
      return this;
    },


    /**
         * Convenience method for calling vm.$emit on vm.$root.
         * @param {string} event
         * @param {*} args
         * @chainable
         */
    emitOnRoot: function emitOnRoot(event) {
      var _$root;

      for (var _len = arguments.length, args = Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++) {
        args[_key - 1] = arguments[_key];
      }

      (_$root = this.$root).$emit.apply(_$root, [event].concat(_toConsumableArray(args)));
      return this;
    }
  },

  beforeDestroy: function beforeDestroy() {
    if (this[BVRL] && isArray(this[BVRL])) {
      while (this[BVRL].length > 0) {
        // shift to process in order
        var _BVRL$shift = this[BVRL].shift(),
            event = _BVRL$shift.event,
            callback = _BVRL$shift.callback;

        this.$root.$off(event, callback);
      }
    }
  }
};