utils.js

import { animatedScrollTo } from 'es6-scroll-to'
import { easeInOutQuad } from 'es6-easings'

class Utils {
  constructor () {
    this.queryString = {}

    let query = window.location.search.substring(1)
    let vars = query.split('&')
    vars.map(v => {
      var pair = v.split('=')
      if (typeof this.queryString[pair[0]] === 'undefined') {
        this.queryString[pair[0]] = decodeURIComponent(pair[1])
      } else if (typeof this.queryString[pair[0]] === 'string') {
        var arr = [ this.queryString[pair[0]], decodeURIComponent(pair[1]) ]
        this.queryString[pair[0]] = arr
      } else {
        this.queryString[pair[0]].push(decodeURIComponent(pair[1]))
      }
    })

    Array.from(document.querySelectorAll('.back-to-top')).map(el => {
      el.addEventListener('click', e => {
        this.scrollToElement('#top')
        e.preventDefault()
      })
    })
  }

  closest (elem, selector) {
    for (; elem && elem !== document; elem = elem.parentNode) {
      if (elem.matches(selector)) return elem
    }
    return null
  }

  getParamByName (name) {
    return this.queryString[name]
  }

  getAudience () {
    if (document.querySelector('body').classList.contains('hcp')) {
      return 'hcp'
    } else {
      return 'pat'
    }
  }

  debounce (context, callback, wait) {
    let timeout
    return (...args) => {
      clearTimeout(timeout)
      timeout = setTimeout(() => callback.apply(context, args), wait)
    }
  }

  scrollTo (distance) {
    animatedScrollTo(distance)
  }

  scrollToElement (selector, shift) {
    let el
    try {
      el = document.querySelector(selector)
    } catch (e) {
      el = document.body
    }
    if (el) {
      if (!shift) {
        shift = 0
      }
      var offset = el.getBoundingClientRect().top - document.body.getBoundingClientRect().top
      offset -= shift
      this.scrollTo({
        to: parseInt(offset, 10),
        duration: 800,
        easing: easeInOutQuad
      })
    }
  }

  isScrolledIntoView (el) {
    var rect = el.getBoundingClientRect()
    var elemTop = rect.top
    var elemBottom = rect.bottom
    var isVisible = (elemTop >= 0) && (elemBottom <= window.innerHeight)
    return isVisible
  }

  live (eventType, elementQuerySelector, cb) {
    document.addEventListener(eventType, function (event) {
      var qs = document.querySelectorAll(elementQuerySelector)
      if (qs) {
        var el = event.target; var index = -1
        while (el && ((index = Array.prototype.indexOf.call(qs, el)) === -1)) {
          el = el.parentElement
        }
        if (index > -1) {
          cb.call(el, event)
        }
      }
    })
  }
}

export default new Utils()

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