前端项目常用工具函数集

export function parseTime(time, cFormat) {
if (arguments.length === 0 || !time) {
return null
}
const format = cFormat || ‘{y}-{m}-{d} {h}:{i}:{s}’
let date
if (typeof time === ‘object’) {
date = time
} else {
if ((typeof time === ‘string’)) {
if ((/¹+$/.test(time))) {
// support “1548221490638”
time = parseInt(time)
} else {
// support safari
// https://stackoverflow.com/questions/4310953/invalid-date-in-safari
time = time.replace(new RegExp(/-/gm), ‘/’)
}
}

if ((typeof time === 'number') && (time.toString().length === 10)) {
  time = time * 1000
}
date = new Date(time)

}
const formatObj = {
y: date.getFullYear(),
m: date.getMonth() + 1,
d: date.getDate(),
h: date.getHours(),
i: date.getMinutes(),
s: date.getSeconds(),
a: date.getDay()
}
const time_str = format.replace(/{([ymdhisa])+}/g, (result, key) => {
const value = formatObj[key]
// Note: getDay() returns 0 on Sunday
if (key === ‘a’) { return [‘日’, ‘一’, ‘二’, ‘三’, ‘四’, ‘五’, ‘六’][value ] }
return value.toString().padStart(2, ‘0’)
})
return time_str
}

/**

• @param {number} time
• @param {string} option
• @returns {string}
  */
  export function formatTime(time, option) {
  if ((’’ + time).length === 10) {
  time = parseInt(time) * 1000
  } else {
  time = +time
  }
  const d = new Date(time)
  const now = Date.now()

const diff = (now - d) / 1000

if (diff < 30) {
return ‘刚刚’
} else if (diff < 3600) {
// less 1 hour
return Math.ceil(diff / 60) + ‘分钟前’
} else if (diff < 3600 * 24) {
return Math.ceil(diff / 3600) + ‘小时前’
} else if (diff < 3600 * 24 * 2) {
return ‘1天前’
}
if (option) {
return parseTime(time, option)
} else {
return (
d.getMonth() +
1 +
‘月’ +
d.getDate() +
‘日’ +
d.getHours() +
‘时’ +
d.getMinutes() +
‘分’
)
}
}

/**

• @param {string} url
• @returns {Object}
  /
  export function getQueryObject(url) {
  url = url == null ? window.location.href : url
  const search = url.substring(url.lastIndexOf(’?’) + 1)
  const obj = {}
  const reg = /([^?&=]+)=([?&=])/g
  search.replace(reg, (rs, $1, $2) => {
  const name = decodeURIComponent($1)
  let val = decodeURIComponent($2)
  val = String(val)
  obj[name] = val
  return rs
  })
  return obj
  }

/**

• @param {string} input value
• @returns {number} output value
  */
  export function byteLength(str) {
  // returns the byte length of an utf8 string
  let s = str.length
  for (var i = str.length - 1; i >= 0; i–) {
  const code = str.charCodeAt(i)
  if (code > 0x7f && code <= 0x7ff) s++
  else if (code > 0x7ff && code <= 0xffff) s += 2
  if (code >= 0xDC00 && code <= 0xDFFF) i–
  }
  return s
  }

/**

• @param {Array} actual
• @returns {Array}
  */
  export function cleanArray(actual) {
  const newArray = []
  for (let i = 0; i < actual.length; i++) {
  if (actual[i]) {
  newArray.push(actual[i])
  }
  }
  return newArray
  }

/**

• @param {Object} json
• @returns {Array}
  */
  export function param(json) {
  if (!json) return ‘’
  return cleanArray(
  Object.keys(json).map(key => {
  if (json[key] === undefined) return ‘’
  return encodeURIComponent(key) + ‘=’ + encodeURIComponent(json[key])
  })
  ).join(’&’)
  }

/**

• @param {string} url
• @returns {Object}
  */
  export function param2Obj(url) {
  const search = decodeURIComponent(url.split(’?’)[1]).replace(/+/g, ’ ‘)
  if (!search) {
  return {}
  }
  const obj = {}
  const searchArr = search.split(’&’)
  searchArr.forEach(v => {
  const index = v.indexOf(’=’)
  if (index !== -1) {
  const name = v.substring(0, index)
  const val = v.substring(index + 1, v.length)
  obj[name] = val
  }
  })
  return obj
  }

/**

• @param {string} val
• @returns {string}
  */
  export function html2Text(val) {
  const div = document.createElement(‘div’)
  div.innerHTML = val
  return div.textContent || div.innerText
  }

/**

• Merges two objects, giving the last one precedence
• @param {Object} target
• @param {(Object|Array)} source
• @returns {Object}
  */
  export function objectMerge(target, source) {
  if (typeof target !== ‘object’) {
  target = {}
  }
  if (Array.isArray(source)) {
  return source.slice()
  }
  Object.keys(source).forEach(property => {
  const sourceProperty = source[property]
  if (typeof sourceProperty === ‘object’) {
  target[property] = objectMerge(target[property], sourceProperty)
  } else {
  target[property] = sourceProperty
  }
  })
  return target
  }

/**

• @param {HTMLElement} element
• @param {string} className
  */
  export function toggleClass(element, className) {
  if (!element || !className) {
  return
  }
  let classString = element.className
  const nameIndex = classString.indexOf(className)
  if (nameIndex === -1) {
  classString += ‘’ + className
  } else {
  classString =
  classString.substr(0, nameIndex) +
  classString.substr(nameIndex + className.length)
  }
  element.className = classString
  }

/**

• @param {string} type
• @returns {Date}
  */
  export function getTime(type) {
  if (type === ‘start’) {
  return new Date().getTime() - 3600 * 1000 * 24 * 90
  } else {
  return new Date(new Date().toDateString())
  }
  }

/**

• @param {Function} func
• @param {number} wait
• @param {boolean} immediate
• @return {*}
  */
  export function debounce(func, wait, immediate) {
  let timeout, args, context, timestamp, result

const later = function() {
// 据上一次触发时间间隔
const last = +new Date() - timestamp

// 上次被包装函数被调用时间间隔 last 小于设定时间间隔 wait
if (last < wait && last > 0) {
  timeout = setTimeout(later, wait - last)
} else {
  timeout = null
  // 如果设定为immediate===true，因为开始边界已经调用过了此处无需调用
  if (!immediate) {
    result = func.apply(context, args)
    if (!timeout) context = args = null
  }
}

}

return function(…args) {
context = this
timestamp = +new Date()
const callNow = immediate && !timeout
// 如果延时不存在，重新设定延时
if (!timeout) timeout = setTimeout(later, wait)
if (callNow) {
result = func.apply(context, args)
context = args = null
}

return result

}
}

/**

• This is just a simple version of deep copy
• Has a lot of edge cases bug
• If you want to use a perfect deep copy, use lodash’s _.cloneDeep
• @param {Object} source
• @returns {Object}
  */
  export function deepClone(source) {
  if (!source && typeof source !== ‘object’) {
  throw new Error(‘error arguments’, ‘deepClone’)
  }
  const targetObj = source.constructor === Array ? [] : {}
  Object.keys(source).forEach(keys => {
  if (source[keys] && typeof source[keys] === ‘object’) {
  targetObj[keys] = deepClone(source[keys])
  } else {
  targetObj[keys] = source[keys]
  }
  })
  return targetObj
  }

/**

• @param {Array} arr
• @returns {Array}
  */
  export function uniqueArr(arr) {
  return Array.from(new Set(arr))
  }

/**

• @returns {string}
  */
  export function createUniqueString() {
  const timestamp = +new Date() + ‘’
  const randomNum = parseInt((1 + Math.random()) * 65536) + ‘’
  return (+(randomNum + timestamp)).toString(32)
  }

/**

• Check if an element has a class
• @param {HTMLElement} elm
• @param {string} cls
• @returns {boolean}
  */
  export function hasClass(ele, cls) {
  return !!ele.className.match(new RegExp(’(\s|^)’ + cls + ‘(\s|$)’))
  }

/**

• Add class to element
• @param {HTMLElement} elm
• @param {string} cls
  */
  export function addClass(ele, cls) {
  if (!hasClass(ele, cls)) ele.className += ’ ’ + cls
  }

/**

• Remove class from element
• @param {HTMLElement} elm
• @param {string} cls
  */
  export function removeClass(ele, cls) {
  if (hasClass(ele, cls)) {
  const reg = new RegExp(’(\s|^)’ + cls + ‘(\s|$)’)
  ele.className = ele.className.replace(reg, ’ ')
  }
  }

/**

• Show plural label if time is plural number
• @param {number} time
• @param {string} label
• @return {string}
  */
  function pluralize(time, label) {
  if (time === 1) {
  return time + label
  }
  return time + label + ‘s’
  }

/**

• @param {number} time
  */
  export function timeAgo(time) {
  const between = Date.now() / 1000 - Number(time)
  if (between < 3600) {
  return pluralize((between / 60), ’ minute’)
  } else if (between < 86400) {
  return pluralize((between / 3600), ’ hour’)
  } else {
  return pluralize(~~(between / 86400), ’ day’)
  }
  }

/**

• Number formatting
• like 10000 => 10k
• @param {number} num
• @param {number} digits
  */
  export function numberFormatter(num, digits) {
  const si = [
  { value: 1E18, symbol: ‘E’ },
  { value: 1E15, symbol: ‘P’ },
  { value: 1E12, symbol: ‘T’ },
  { value: 1E9, symbol: ‘G’ },
  { value: 1E6, symbol: ‘M’ },
  { value: 1E3, symbol: ‘k’ }
  ]
  for (let i = 0; i < si.length; i++) {
  if (num >= si[i].value) {
  return (num / si[i].value).toFixed(digits).replace(/.0+KaTeX parse error: Can't use function '\.' in math mode at position 3: |(\̲.̲[0-9]*[1-9])0+/, ‘$1’) + si[i].symbol
  }
  }
  return num.toString()
  }

/**

• 10000 => “10,000”
• @param {number} num
  */
  export function toThousandFilter(num) {
  return (+num || 0).toString().replace(/^-?\d+/g, m => m.replace(/(?=(?!\b)(\d{3})+$)/g, ‘,’))
  }

/**

• Upper case first char
• @param {String} string
  */
  export function uppercaseFirst(string) {
  return string.charAt(0).toUpperCase() + string.slice(1)
  }

// 文件流转blob对象下载
export function downLoadFileBlob(file, fileType, name, isDate) {
let fileName = name
// isDate 默认不加时间拼接
if (isDate) {
fileName = fileName + ‘’ + parseTime(new Date())
}
if (window.navigator.msSaveOrOpenBlob) {
// 兼容ie11
const blob_ie = new Blob([file])
window.navigator.msSaveOrOpenBlob(blob_ie, fileName + ‘.’ + fileType)
} else {
const blob = new Blob([file], { type: ‘application/’ + fileType + ‘;charset=utf-8’ })
const url = window.URL.createObjectURL(blob)
const a = document.createElement(‘a’)
a.style.display = ‘none’
a.href = url
a.download = fileName + ‘.’ + fileType
a.target = ‘_blank’
document.body.appendChild(a)
a.click()
document.body.removeChild(a) // 下载完成移除元素
window.URL.revokeObjectURL(url) // 释放掉blob对象
}
}

/* 递归循环 */
export function loopFn(data, key, value, title) {
const tempData = []
data.forEach(function(item, index) {
let tempChildren
if (item.children && item.children.length > 0) {
tempChildren = loopFn(item.children, key, value, title)
}
tempData.push({
key: item[key || ‘id’],
value: item[value || ‘id’],
title: item[title || ‘name’],
children: tempChildren
})
})
return tempData
}

// 判断当前设备类型
export function getDeviceType() {
let res = ‘’
if (!window.navigator) {
res = ‘WEBAPP’
} else if (/Mobile|Android|webOS|iPhone|iPad|Phone/i.test(navigator.userAgent)) {
res = ‘H5’
} else {
res = ‘PC’
}
return res
}

/**

• @description: 在提效表单时,去掉输入框中的首尾空格
• @param {Object} data 表单数据
• @return {Object} 返回去掉首尾空格的参数值
  */
  export function clearSpace(data) {
  const newData = {}
  for (const key in data) {
  if (data[key] && typeof(data[key]) === ‘string’) {
  newData[key] = data[key].trim()
  }
  }
  const finalData = Object.assign(data, newData)
  return finalData
  }

/**

• @description: 判断文件类型是否为可选类型
• @param {string} file 文件名
• @param {string} accept 可选的文件类型
• @return {boolean} 返回是否为可选类型
  */
  export function isType(file, accept) {
  const index = file.lastIndexOf(’.’)
  const suffix = file.substr(index+1)
  return accept.indexOf(suffix.toLowerCase()) === -1
  }

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1. 0-9 ↩︎