bootstrap-vue/es/directives/scrollspy/scrollspy.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.

var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { return typeof obj; } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; };

/*
 * ScrollSpy directive v-b-scrollspy
 */

import ScrollSpy from './scrollspy.class';
import { keys } from '../../utils/object';

var inBrowser = typeof window !== 'undefined';
var isServer = !inBrowser;

// Key we use to store our Instance
var BVSS = '__BV_ScrollSpy__';

// Generate config from bindings
/* istanbul ignore next: not easy to test */
function makeConfig(binding) {
  var config = {};

  // If Argument, assume element ID
  if (binding.arg) {
    // Element ID specified as arg. We must pre-pend #
    config.element = '#' + binding.arg;
  }

  // Process modifiers
  keys(binding.modifiers).forEach(function (mod) {
    if (/^\d+$/.test(mod)) {
      // Offest value
      config.offset = parseInt(mod, 10);
    } else if (/^(auto|position|offset)$/.test(mod)) {
      // Offset method
      config.method = mod;
    }
  });

  // Process value
  if (typeof binding.value === 'string') {
    // Value is a CSS ID or selector
    config.element = binding.value;
  } else if (typeof binding.value === 'number') {
    // Value is offset
    config.offset = Math.round(binding.value);
  } else if (_typeof(binding.value) === 'object') {
    // Value is config object
    // Filter the object based on our supported config options
    keys(binding.value).filter(function (k) {
      return Boolean(ScrollSpy.DefaultType[k]);
    }).forEach(function (k) {
      config[k] = binding.value[k];
    });
  }

  return config;
}

/* istanbul ignore next: not easy to test */
function addBVSS(el, binding, vnode) {
  if (isServer) {
    return;
  }
  var cfg = makeConfig(binding);
  if (!el[BVSS]) {
    el[BVSS] = new ScrollSpy(el, cfg, vnode.context.$root);
  } else {
    el[BVSS].updateConfig(cfg, vnode.context.$root);
  }
  return el[BVSS];
}

/* istanbul ignore next: not easy to test */
function removeBVSS(el) {
  if (el[BVSS]) {
    el[BVSS].dispose();
    el[BVSS] = null;
  }
}

/*
 * Export our directive
 */

/* istanbul ignore next: not easy to test */
export default {
  bind: function bind(el, binding, vnode) {
    addBVSS(el, binding, vnode);
  },
  inserted: function inserted(el, binding, vnode) {
    addBVSS(el, binding, vnode);
  },
  update: function update(el, binding, vnode) {
    addBVSS(el, binding, vnode);
  },
  componentUpdated: function componentUpdated(el, binding, vnode) {
    addBVSS(el, binding, vnode);
  },
  unbind: function unbind(el) {
    if (isServer) {
      return;
    }
    // Remove scroll event listener on scrollElId
    removeBVSS(el);
  }
};