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View Code? Open in Web Editor NEW前端笔记(持续更新.)
前端笔记(持续更新.)
import Vue from 'vue'
export default function pushQin(f, token, cak) {
var fp = [] // 空数组,存放批量上传后返回的url
for(let i in f){
let param = new FormData(); //创建form对象
// 文件名字
param.append('key', f[i].file.name);
// 七牛识别的上传凭证token
param.append('token', token);
// 文件资源
param.append('file', f[i].file);
Vue.http
.post("http://upload.qiniu.com", param, {
emulateJSON: true,
headers: {
"Content-Type": "multipart/form-data"
}
})
.then(r => {
fp.push('https://ohp96o3wl.qnssl.com/' + r.body.key)
if(fp.length == f.length){
cak(fp)
}
})
.catch(e => {
console.log(e);
});
}
// let param = new FormData(); //创建form对象
// param.append('key', t[0].file.name);
// param.append('token', this.token.qn_upToken);
// param.append('file', t[0].file);
// Vue.http
// .post("http://upload.qiniu.com", param, {
// emulateJSON: true,
// headers: {
// "Content-Type": "multipart/form-data"
// }
// })
// .then(r => {
// console.log('https://ohp96o3wl.qnssl.com/' + r.body.key);
// })
// .catch(e => {
// console.log(e);
// });
}
promise规定了一种方法,就是在then里面返回一个新的promise,称为promise2:promise2 = new Promise((resolve, reject)=>{})
function thenPromise(PromiseRelase, x, resolve, reject){
//判断x是不是在等待自己的resolve
// let p = new Promise(resolve => {
// resolve(0);
// });
// var p2 = p.then(data => {
// // 循环引用,自己等待自己完成,一辈子完不成
// return p2;
// })
if(x === PromiseRelase){
return reject(TypeError('Chaining cycle detected for promise'))
}
let repeat; // 防止重复调用
if(x != null && (typeof x === 'object' || typeof x === 'function')){
try {
// Promise A+规定,声明then == x的方法,,,
let then = x.then
// 如果then不是一个方法,也就是说then不是一个new promise,是一个普通的值
if(typeof then == 'function'){
// x是一个new Promise,所以会有then方法
then.call(x, y => {
if(repeat) return;
repeat = true;
// 如果resolve还是一个promise,继续递归解析
thenPromise(PromiseRelase, y, resolve, reject)
}, e => {
if(repeat) return;
repeat = true;
reject(e)
})
}else{
resolve(x)
}
} catch (e) {
// 异常也会报错
if(repeat) return;
repeat = true;
reject(e)
}
}else{
// x是一个普通值,可以直接输出
resolve(x)
}
}
class Promise{
constructor(fn){
this.state = 'pending'; // 当前状态值, pending---等待,resolve---成功,reject---失败
this.value = null; // 成功的值
this.err = null; // 失败的原因
this.onFulfilledCallbacks = [] // 存放then成功的数组
this.onRejectedCallbacks = [] // 存放this失败的数组
let resolve = value => { // 成功的回调
if(this.state == 'pending'){ // 等待的状态下赋值并且执行成功数组的回调
this.value = value
this.state = 'fulfilled';
this.onFulfilledCallbacks.forEach(fn => fn()) // 赋值后依次执行成功里的回调
}
}
let reject = err => { // 与resolve同理
if(this.state == 'pending'){
this.err = err
this.state = 'rejected'
this.onRejectedCallbacks.forEach(fn => fn()) // 赋值后依次执行失败里的回调
}
}
try {
fn(resolve, reject);
} catch (error) {
reject(error)
}
}
then(onFulfilled, onRejected){
// 如果不是function,则直接输出值
onFulfilled = typeof onFulfilled === 'function' ? onFulfilled : value => value;
onRejected = typeof onRejected === 'function' ? onRejected : err => ( TypeError(err) );
let PromiseRelase = new Promise( (resolve, reject) => {// 声明要返回的promise,用于链式调用then
if(this.state == 'fulfilled'){
// 使用setTimeout()实现then中onFulfilled和onRejected不能同步调用,只能异步调用,Promise A+规范规定
setTimeout(() => {
try {
var x = onFulfilled(this.value) // 相当于 x.then( onFulfilled(this.value) => {...}) value就是resolve的值
// 将then--------return的x值传给下一个then
thenPromise(PromiseRelase, x, resolve, reject)
} catch (e) {
reject(e)
}
}, 0)
}
if(this.state == 'reject'){
setTimeout(()=>{
try {
var x = onRejected(this.err) // 同上
thenPromise(PromiseRelase, x, resolve, reject)
} catch (e) {
reject(e)
}
}, 0)
}
if(this.state == 'pending'){ // 当异步时,state还未改变
this.onFulfilledCallbacks.push(()=>{ // 将成功的回调保存至数组中,当resolve执行时执行数组中的回调函数
setTimeout(() => {
try {
var x = onFulfilled(this.value)
thenPromise(PromiseRelase, x, resolve, reject)
} catch (e) {
reject(e)
}
}, 0)
})
this.onRejectedCallbacks.push(()=>{ // 将失败的回调保存至数组中,当reject执行时执行数组中的回调函数
var x = onRejected(this.err)
thenPromise(PromiseRelase, x, resolve, reject)
})
}
})
// 链式then
return PromiseRelase;
}
}
var pro = new Promise(rev => {
rev(123)
})
pro.then(res => {
return new Promise(rev => {
rev(1111)
})
}).then( res => {
return new Promise(rev => {
rev(222)
})
}).then( res => {
// console.log(res)
})
v8官网实现promise:https://chromium.googlesource.com/v8/v8/+/3.29.45/src/promise.js?autodive=0/
https://juejin.im/post/5b2f02cd5188252b937548ab#heading-0
过滤无效的值
[undefined,null,,123,123,123].filter(_=>_)
简单粗暴实现深拷贝
JSON.parse(JSON.stringify(obj))
用JSON实现深拷贝
刚建项目时config是默认隐藏的,需要npm run eject
webpack.config.dev.js , webpack.config.prod.js中找到exclude 添加/.scss$/
在rules中添加 { test: /\.scss$/, loaders: ['style-loader', 'css-loader', 'sass-loader'],},
dev只是在开发环境下,生产环境下需要改prod下的,内容一样
import Vue from 'vue'
export default function pushQin(f, token, cak) {
var fp = [] // 空数组,存放批量上传后返回的url
for(let i in f){
let param = new FormData(); //创建form对象
// 文件名字
param.append('key', f[i].file.name);
// 七牛识别的上传凭证token
param.append('token', token);
// 文件资源
param.append('file', f[i].file);
Vue.http
.post("http://upload.qiniu.com", param, {
emulateJSON: true,
headers: {
"Content-Type": "multipart/form-data"
}
})
.then(r => {
fp.push('https://ohp96o3wl.qnssl.com/' + r.body.key)
if(fp.length == f.length){
cak(fp)
}
})
.catch(e => {
console.log(e);
});
}
// let param = new FormData(); //创建form对象
// param.append('key', t[0].file.name);
// param.append('token', this.token.qn_upToken);
// param.append('file', t[0].file);
// Vue.http
// .post("http://upload.qiniu.com", param, {
// emulateJSON: true,
// headers: {
// "Content-Type": "multipart/form-data"
// }
// })
// .then(r => {
// console.log('https://ohp96o3wl.qnssl.com/' + r.body.key);
// })
// .catch(e => {
// console.log(e);
// });
}
在vue里想action,this.dispatch其他文件的action,未打包之前正常,但是打包会有问题
解决办法:注入文件,直接使用state赋值,如:
import hhotel from './hotel-form'
hhotel.state.fileCtns = record.proofImg ? record.proofImg.split(',') : []
一般调用相机是:capture='camera' ,但是在ios上 capture=''也会调用,必须没有capture属性才可以
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