bootstrap-vue/esm/directives/scrollspy/scrollspy.js

BootstrapVue, with over 40 plugins and more than 80 custom components, custom directives, and over 300 icons, provides one of the most comprehensive implementations of Bootstrap v4 components and grid system for Vue.js. With extensive and automated WAI-AR

import ScrollSpy from './scrollspy.class';
import { isBrowser } from '../../utils/env';
import { keys } from '../../utils/object';
import { isNumber, isObject, isString } from '../../utils/inspect'; // Key we use to store our instance

var BV_SCROLLSPY = '__BV_ScrollSpy__'; // Pre-compiled regular expressions

var onlyDigitsRE = /^\d+$/;
var offsetRE = /^(auto|position|offset)$/; // Build a ScrollSpy config based on bindings (if any)
// Arguments and modifiers take precedence over passed value config object

/* istanbul ignore next: not easy to test */

var parseBindings = function parseBindings(bindings)
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{
  var config = {}; // If argument, assume element ID

  if (bindings.arg) {
    // Element ID specified as arg
    // We must prepend '#' to become a CSS selector
    config.element = "#".concat(bindings.arg);
  } // Process modifiers


  keys(bindings.modifiers).forEach(function (mod) {
    if (onlyDigitsRE.test(mod)) {
      // Offset value
      config.offset = parseInt(mod, 10);
    } else if (offsetRE.test(mod)) {
      // Offset method
      config.method = mod;
    }
  }); // Process value

  if (isString(bindings.value)) {
    // Value is a CSS ID or selector
    config.element = bindings.value;
  } else if (isNumber(bindings.value)) {
    // Value is offset
    config.offset = Math.round(bindings.value);
  } else if (isObject(bindings.value)) {
    // Value is config object
    // Filter the object based on our supported config options
    keys(bindings.value).filter(function (k) {
      return !!ScrollSpy.DefaultType[k];
    }).forEach(function (k) {
      config[k] = bindings.value[k];
    });
  }

  return config;
}; // Add or update ScrollSpy on our element


var applyScrollspy = function applyScrollspy(el, bindings, vnode)
/* istanbul ignore next: not easy to test */
{
  if (!isBrowser) {
    /* istanbul ignore next */
    return;
  }

  var config = parseBindings(bindings);

  if (el[BV_SCROLLSPY]) {
    el[BV_SCROLLSPY].updateConfig(config, vnode.context.$root);
  } else {
    el[BV_SCROLLSPY] = new ScrollSpy(el, config, vnode.context.$root);
  }
}; // Remove ScrollSpy on our element

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var removeScrollspy = function removeScrollspy(el)
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{
  if (el[BV_SCROLLSPY]) {
    el[BV_SCROLLSPY].dispose();
    el[BV_SCROLLSPY] = null;
    delete el[BV_SCROLLSPY];
  }
};
/*
 * Export our directive
 */


export var VBScrollspy = {
  bind: function bind(el, bindings, vnode)
  /* istanbul ignore next: not easy to test */
  {
    applyScrollspy(el, bindings, vnode);
  },
  inserted: function inserted(el, bindings, vnode)
  /* istanbul ignore next: not easy to test */
  {
    applyScrollspy(el, bindings, vnode);
  },
  update: function update(el, bindings, vnode)
  /* istanbul ignore next: not easy to test */
  {
    if (bindings.value !== bindings.oldValue) {
      applyScrollspy(el, bindings, vnode);
    }
  },
  componentUpdated: function componentUpdated(el, bindings, vnode)
  /* istanbul ignore next: not easy to test */
  {
    if (bindings.value !== bindings.oldValue) {
      applyScrollspy(el, bindings, vnode);
    }
  },
  unbind: function unbind(el)
  /* istanbul ignore next: not easy to test */
  {
    removeScrollspy(el);
  }
};