dwui/utils/assist.js

a part of wrapper on iView UI

/**
 * 比较两个数组中 返回newArr相对oldArr发生变化的数据
 * @param oldArr 变动之前的数组副本
 * @param newArr 变动之后的数据
 * @return {Array} 返回变动的数据,actionType标记发生的变化
 */
export function compareArr (oldArr, newArr) {
  let changeItems = []
  if (oldArr.length === 0) {
    if (newArr.length > 0) {
      for (let j = 0; j < newArr.length; j++) {
        if ((!checkIsEmptyObject(newArr[j], '$actionType'))) {
          changeItems.push(deepCopy(newArr[j]))
        }
      }
      return changeItems
    } else {
      return []
    }
  }
  newArr.forEach((item) => {
    if (item.$actionType === 'update') {
      for (let i = 0; i < oldArr.length; i++) {
        if (compareObject(item, oldArr[i])) {
          break
        }
        if (i === oldArr.length - 1) {
          changeItems.push(deepCopy(item))
        }
      }
    } else {
      if ((!checkIsEmptyObject(item, '$actionType'))) {
        changeItems.push(deepCopy(item))
      }
    }
  })
  return changeItems
}

/**
 * 根据对象删除数组中的数据的第一个值，返回新数组
 * @param arr 数据数组
 * @param delObject 需要删除的对象
 * @return {Array} 返回 arr 中删除掉 delObject 后的新数组
 */
export function delArrObject (arr, delObject) {
  let newArr = []
  let hasDelete = false
  let deepCopyObj = deepCopy(delObject)
  if (arr.length === 0) {
    return newArr
  } else {
    arr.forEach((item) => {
      if (!compareObject(item, deepCopyObj) || hasDelete) {
        newArr.push(item)
      } else {
        hasDelete = true
      }
    })
    return newArr
  }
}

/**
 * 返回typeOf 类类型
 * @param obj
 * @return {*}
 */
function typeOf (obj) {
  const toString = Object.prototype.toString
  const map = {
    '[object Boolean]': 'boolean',
    '[object Number]': 'number',
    '[object String]': 'string',
    '[object Function]': 'function',
    '[object Array]': 'array',
    '[object Date]': 'date',
    '[object RegExp]': 'regExp',
    '[object Undefined]': 'undefined',
    '[object Null]': 'null',
    '[object Object]': 'object'
  }
  return map[toString.call(obj)]
}

/**
 * 深复制一个对象
 * @param data
 * @return {*}
 */
function deepCopy (data) {
  const t = typeOf(data)
  let o

  if (t === 'array') {
    o = []
  } else if (t === 'object') {
    o = {}
  } else {
    return data
  }

  if (t === 'array') {
    for (let i = 0; i < data.length; i++) {
      o.push(deepCopy(data[i]))
    }
  } else if (t === 'object') {
    for (let i in data) {
      o[i] = deepCopy(data[i])
    }
  }
  return o
}

export { deepCopy }

/**
 * 比较对象是否相等（无嵌套的属性）
 * @param x
 * @param y
 * @return {boolean} true：相等 false:不相等
 * @note: 忽略$actionType,$rowKeyIndex 属性的比较
 */
export function compareObject (x, y) {
  if (x === y) {
    return true
  }
  if (!(x instanceof Object) || !(y instanceof Object)) {
    return false
  }
  for (let p in x) {
    // Inherited properties were tested using x.constructor === y.constructor
    if (p === '$actionType' || p === '$rowKeyIndex') {
      continue
    }
    if (x.hasOwnProperty(p)) {
      // Allows comparing x[ p ] and y[ p ] when set to undefined
      if (!y.hasOwnProperty(p)) {
        return false
      }

      // If they have the same strict value or identity then they are equal
      if (x[ p ] === y[ p ]) {
        continue
      }

      // Numbers, Strings, Functions, Booleans must be strictly equal
      if (typeof (x[ p ]) !== 'object') {
        return false
      }
      if (Array.isArray(x[ p ])) {
        if (x[p] === y[p]) {
          continue
        } else if (x[p].length === y[p].length) {
          if (x[p].toString() === y[p].toString()) {
            continue
          } else {
            return false
          }
        } else {
          return false
        }
      }
      // Objects and Arrays must be tested recursively
      if (!Object.equals(x[ p ], y[ p ])) {
        return false
      }
    }
  }

  for (let p in y) {
    // allows x[ p ] to be set to undefined
    if (y.hasOwnProperty(p) && !x.hasOwnProperty(p)) {
      return false
    }
  }
  return true
}

/**
 * 判断某个对象是否为空
 * @param o 需要比较的对象
 * @param filterProperty 判断为空过程中需要忽略的属性
 * @return {boolean} true:对象为空 false:对象不为空
 */
function checkIsEmptyObject (o, filterProperty) {
  let properties = Object.getOwnPropertyNames(o)
  if (properties.length === 0) {
    return true
  } else {
    let flag = true
    properties.forEach((pro) => {
      if (pro !== filterProperty && pro !== '$rowKeyIndex' && pro !== '__ob__' && pro !== 'state') {
        if (o[pro]) {
          flag = false
        }
      }
    })
    return flag
  }
}

// For Modal scrollBar hidden
let cached
export function getScrollBarSize () {
  if (cached === undefined) {
    const inner = document.createElement('div')
    inner.style.width = '100%'
    inner.style.height = '200px'

    const outer = document.createElement('div')
    const outerStyle = outer.style

    outerStyle.position = 'absolute'
    outerStyle.top = 0
    outerStyle.left = 0
    outerStyle.pointerEvents = 'none'
    outerStyle.visibility = 'hidden'
    outerStyle.width = '200px'
    outerStyle.height = '150px'
    outerStyle.overflow = 'hidden'

    outer.appendChild(inner)

    document.body.appendChild(outer)

    const widthContained = inner.offsetWidth
    outer.style.overflow = 'scroll'
    let widthScroll = inner.offsetWidth

    if (widthContained === widthScroll) {
      widthScroll = outer.clientWidth
    }

    document.body.removeChild(outer)

    cached = widthContained - widthScroll
  }
  return cached
}