castle-haozijunqaq-utils
Version:
Common development utils
378 lines (355 loc) • 13 kB
JavaScript
const getChildren = (arr, pid, pidKey) => {
let result = [];
for (let i = 0; i < arr.length; i++) {
if (arr[i][pidKey] === pid) {
result.push(arr[i]);
}
}
return result;
};
const mapChildren = (arr, result, pidKey, idKey) => {
if (result.length === 0) {
return
}
for (let i = 0; i < result.length; i++) {
result[i].children = getChildren(arr, result[i][idKey], pidKey);
mapChildren(arr, result[i].children, pidKey);
}
};
export default {
/**
* 数组去重
* @param arr 去重数组
* @returns {any[]}
*/
uniq(arr) {
return [...new Set(arr)];
},
/**
* 数组取最大值
* @param arr
* @returns {number}
*/
max(arr) {
return Math.max.apply(null, arr);
},
/**
* 数组取最小值
* @param arr
* @returns {number}
*/
min(arr) {
return Math.min.apply(null, arr);
},
/**
* 对象数组排序
* @param arr
* @param attr 属性key
* @param order 排序方式 asc 升序 desc 降序
*/
sortBy(arr, attr, order = 'asc') {
const copy = JSON.parse(JSON.stringify(arr));
for (let i = 0; i < copy.length - 1; i++) {
for (let j = 0; j < copy.length - 1 - i; j++) {
if (typeof copy[j] === 'object' && !Array.isArray(copy[j])) {
if (order === 'asc') {
if (copy[j][attr] > copy[j + 1][attr]) {
const temp = copy[j];
copy[j] = copy[j + 1];
copy[j + 1] = temp;
}
} else if (order === 'desc') {
if (copy[j][attr] < copy[j + 1][attr]) {
const temp = copy[j];
copy[j] = copy[j + 1];
copy[j + 1] = temp;
}
}
} else {
throw Error('item type is invalid')
}
}
}
return copy;
},
/**
* 构建树形结构(不会改变原数组)
* @param {Array} arr 所有节点组成的数组
* @param {String | null} rootId 根节点id的pid 如果没有传null
* @param {String} idKey id的键名
* @param {String} pidKey pid的键名
* @returns {Array}
*/
formatTree(arr, rootId, idKey, pidKey) {
let result = [];
for (let i = 0; i < arr.length; i++) {
if (arr[i][pidKey] === rootId || arr[i][pidKey] === undefined) {
result.push(arr[i]);
}
}
for (let i = 0; i < result.length; i++) {
result[i].children = getChildren(arr, result[i][idKey], pidKey);
mapChildren(arr, result[i].children, pidKey, idKey);
}
return result
},
/**
* 格式化时间戳
* @param {Number | Date} time 毫秒时间戳 | 时间对象
* @param {String} fmt 格式化方式
* @returns {*}
*/
formatDate(time, fmt) {
if (!time) return '';
let date = typeof time === 'number' ? new Date(time) : time;
const expList = {
"M+": date.getMonth() + 1, //月份
"d+": date.getDate(), //日
"H+": date.getHours(), //小时
"h+": date.getHours() <= 12 ? date.getHours() : date.getHours() - 12, //12制小时
"m+": date.getMinutes(), //分
"s+": date.getSeconds(), //秒
"q+": Math.floor((date.getMonth() + 3) / 3), //季度
"S": date.getMilliseconds(), //毫秒
"n": date.getHours() < 12 ? 'AM' : 'PM', //上午am,下午pm
};
if (/(y+)/.test(fmt))
fmt = fmt.replace(RegExp.$1, (date.getFullYear() + '').substr(4 - RegExp.$1.length));
for (let exp in expList) {
if (new RegExp(`(${exp})`).test(fmt)) {
fmt = fmt.replace(RegExp.$1, (RegExp.$1.length === 1) ?
(expList[exp]) : ((`00${expList[exp]}`).substr((`${expList[exp]}`).length)));
}
}
return fmt;
},
/**
* 随机数方法,取[min, max]
* @param min 最小值
* @param max 最大值
* @returns {number}
*/
random(min, max) {
return Math.floor(Math.random() * (max - min + 1) + min);
},
/**
* 函数柯里化
* @param fn {function} 需要函数柯里化的函数
* @param args 需要被解耦的参数集
*/
curring(fn, ...args) {
return (..._args) => {
return fn.call(this, ...args, ..._args);
}
},
/**
* 浏览器直接下载文件
* @param blob {File | Blob} 文件blob | file 对象
* @param fileName {String} 文件名
*/
download(blob, fileName) {
if ('download' in document.createElement('a')) { // 非IE下载
const elink = document.createElement('a');
elink.download = fileName;
elink.style.display = 'none';
elink.href = window.URL.createObjectURL(blob);
document.body.appendChild(elink);
elink.click();
window.URL.revokeObjectURL(elink.href) ;
document.body.removeChild(elink);
} else { // IE10+下载
navigator.msSaveBlob(blob, fileName);
}
},
/**
* 加载图片完成
* @param imgElement
* @return {Promise<any>}
*/
imgLoad(imgElement) {
return new Promise((resolve) => {
imgElement.onload = (result) => {
resolve(result)
}
})
},
/**
* 压缩(放大)图片
* @param imgFile {File} 图片文件对象
* @param scale {Number} 压缩率
* @param mime {String} 文件类型
* @return {Promise<*|File>}
*/
compressImage(imgFile, scale = 1) {
return new Promise((resolve, reject) => {
let canvas = document.createElement('canvas');
let context = canvas.getContext('2d');
let fileName = imgFile.name;
let imgUrl = window.URL.createObjectURL(imgFile);
let imgElement = document.createElement('img');
imgElement.src = imgUrl;
document.body.appendChild(imgElement);
this.imgLoad(imgElement).then(res => {
let imgWidth = imgElement.width;
let imgHeight = imgElement.height;
canvas.width = imgWidth * scale;
canvas.height = imgHeight * scale;
context.drawImage(imgElement, 0 ,0 ,canvas.width, canvas.height);
let base64 = canvas.toDataURL('image/jpeg');
document.body.removeChild(imgElement);
resolve(this.convertBase64ToFile(base64, fileName))
}).catch(e => {
reject(e)
})
})
},
/**
* 压缩(放大)图片大小
* @param imgFile {File} 图片文件对象
* @param maxSize {Number} 文件大小基准点
* @param isFixSize {Boolean} 是否开启文件大小修正 开启后会等到精度更高的压缩效果
* @return {Promise<*|File>}
*/
compressImageSize(imgFile, maxSize = 100 * 1024, isFixSize = true) {
function appendCanvas(img) {
let canvas = document.createElement('canvas');
let context = canvas.getContext('2d');
let imgUrl = window.URL.createObjectURL(img);
let imgElement = document.createElement('img');
imgElement.src = imgUrl;
document.body.appendChild(imgElement);
return [canvas, imgElement, context]
}
return new Promise((resolve, reject) => {
if (isFixSize) {
this.compressImageSize(imgFile, maxSize, false).then(file => {
let fileName = file.name;
let fileSize = file.size;
if (fileSize <= maxSize) {
resolve(file);
return
}
let scale = (fileSize / maxSize).toFixed(2);
let [canvas, imgElement, context] = appendCanvas(file);
this.imgLoad(imgElement).then(res => {
let imgWidth = imgElement.width;
let imgHeight = imgElement.height;
canvas.width = imgWidth / Math.sqrt(scale);
canvas.height = imgHeight / Math.sqrt(scale);
context.drawImage(imgElement, 0 ,0 ,canvas.width, canvas.height);
let base64 = canvas.toDataURL('image/jpeg', 1);
document.body.removeChild(imgElement);
resolve(this.convertBase64ToFile(base64, fileName))
}).catch(e => {
reject(e)
})
})
} else {
let [canvas, imgElement, context] = appendCanvas(imgFile);
this.imgLoad(imgElement).then(res => {
let imgWidth = imgElement.width;
let imgHeight = imgElement.height;
canvas.width = imgWidth;
canvas.height = imgHeight;
context.drawImage(imgElement, 0 ,0 ,canvas.width, canvas.height);
let base64 = canvas.toDataURL('image/jpeg', 1);
document.body.removeChild(imgElement);
resolve(this.convertBase64ToFile(base64, imgFile.name))
}).catch(e => {
reject(e)
})
}
})
},
/**
* 将base64转成file对象
* @param base64 {String} 带mime前缀的base64字符串
* @param fileName {String} 文件名(后缀强制为mime类型)
* @return {File}
*/
convertBase64ToFile(base64, fileName) {
let arr = base64.split(',');
let mime = arr[0].match(/:(.*?);/)[1];
let bstr = window.atob(arr[1]);
let n = bstr.length;
let u8arr = new Uint8Array(n);
while (n--) {
u8arr[n] = bstr.charCodeAt(n);
}
return new File([u8arr], fileName, {type:mime});
},
/**
* 文件对象转base64字符串
* @param {File} file 文件对象
* @return {Promise<any>}
*/
convertFileToBase64(file) {
return new Promise((resolve, reject) => {
let fileReader = new FileReader();
fileReader.onload = () => {
resolve(fileReader.result);
};
fileReader.onerror = (error) => {
reject(error);
};
fileReader.readAsDataURL(file);
})
},
/**
* 防抖函数
* @param method 事件触发的操作
* @param delay 多少毫秒内连续触发事件，不会执行
* @returns {Function}
*/
debounce(method, delay) {
let timer = null;
return function () {
let self = this;
let args = arguments;
timer && clearTimeout(timer);
timer = setTimeout(function () {
method.apply(self, args);
},delay);
}
},
/**
* 节流函数
* @param method 事件触发的操作
* @param mustRunDelay 间隔多少毫秒需要触发一次事件
*/
throttle(method, mustRunDelay) {
let timer;
let start;
return function loop() {
let self = this;
let now = Date.now();
let args = arguments;
if(!start){
start = now;
}
if(timer){
clearTimeout(timer);
}
if(now - start >= mustRunDelay){
method.apply(self, args);
start = now;
}else {
timer = setTimeout(function () {
loop.apply(self, args);
}, 50);
}
}
},
setSession(key, value) {
window.sessionStorage.setItem(key, JSON.stringify(value));
},
getSession(key) {
return JSON.parse(window.sessionStorage.getItem(key));
},
setLocal(key, value) {
window.localStorage.setItem(key, JSON.stringify(value));
},
getLocal(key) {
return JSON.parse(window.localStorage.getItem(key));
},
}