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

With more than 85 components, over 45 available plugins, several directives, and 1000+ icons, BootstrapVue provides one of the most comprehensive implementations of the Bootstrap v4 component and grid system available for Vue.js v2.6, complete with extens

// @vue/component
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
     *
     * When registering a `$root` listener, it also registers a listener on
     * the component's `beforeDestroy()` hook to automatically remove the
     * event listener from the `$root` instance
     *
     * @param {string} event
     * @param {function} callback
     */
    listenOnRoot: function listenOnRoot(event, callback) {
      var _this = this;

      this.$root.$on(event, callback);
      this.$on('hook:beforeDestroy', function () {
        _this.$root.$off(event, callback);
      });
    },

    /**
     * Safely register a `$once()` event listener 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
     *
     * When registering a $root listener, it also registers a listener on
     * the component's `beforeDestroy` hook to automatically remove the
     * event listener from the $root instance.
     *
     * @param {string} event
     * @param {function} callback
     */
    listenOnRootOnce: function listenOnRootOnce(event, callback) {
      var _this2 = this;

      this.$root.$once(event, callback);
      this.$on('hook:beforeDestroy', function () {
        _this2.$root.$off(event, callback);
      });
    },

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

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

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