在我的应用程序中,我会调用fetchData函数来验证用户身份。如果用户令牌变为无效,应用程序将运行axios.all()
并且我的拦截器将返回许多错误。
如何防止axios.all()
在第一次出错后继续运行?并只向用户显示一个通知?
interceptors.js
export default (http, store, router) => {
http.interceptors.response.use(response => response, (error) => {
const {response} = error;
let message = 'Ops. Algo de errado aconteceu...';
if([401].indexOf(response.status) > -1){
localforage.removeItem('token');
router.push({
name: 'login'
});
Vue.notify({
group: 'panel',
type: 'error',
duration: 5000,
text: response.data.message ? response.data.message : message
});
}
return Promise.reject(error);
})
}
auth.js
const actions = {
fetchData({commit, dispatch}) {
function getChannels() {
return http.get('channels')
}
function getContacts() {
return http.get('conversations')
}
function getEventActions() {
return http.get('events/actions')
}
// 20 more functions calls
axios.all([
getChannels(),
getContacts(),
getEventActions()
]).then(axios.spread(function (channels, contacts, eventActions) {
dispatch('channels/setChannels', channels.data, {root: true})
dispatch('contacts/setContacts', contacts.data, {root: true})
dispatch('events/setActions', eventActions.data, {root: true})
}))
}
}
编辑:@tony19's answer更好,因为它允许取消在第一次错误后仍然挂起的请求,并且不需要任何额外的库。
一种解决方案是为您同时使用的所有请求分配一个唯一标识符(我将在此示例中使用uuid/v4
包,随意使用其他内容):
import uuid from 'uuid/v4'
const actions = {
fetchData({commit, dispatch}) {
const config = {
_uuid: uuid()
}
function getChannels() {
return http.get('channels', config)
}
function getContacts() {
return http.get('conversations', config)
}
function getEventActions() {
return http.get('events/actions', config)
}
// 20 more functions calls
axios.all([
getChannels(),
getContacts(),
getEventActions()
]).then(axios.spread(function (channels, contacts, eventActions) {
dispatch('channels/setChannels', channels.data, {root: true})
dispatch('contacts/setContacts', contacts.data, {root: true})
dispatch('events/setActions', eventActions.data, {root: true})
}))
}
}
然后,在您的拦截器中,您可以选择使用此唯一标识符一次处理错误:
export default (http, store, router) => {
// Here, you create a variable that memorize all the uuid that have
// already been handled
const handledErrors = {}
http.interceptors.response.use(response => response, (error) => {
// Here, you check if you have already handled the error
if (error.config._uuid && handledErrors[error.config._uuid]) {
return Promise.reject(error)
}
// If the request contains a uuid, you tell
// the handledErrors variable that you handled
// this particular uuid
if (error.config._uuid) {
handledErrors[error.config._uuid] = true
}
// And then you continue on your normal behavior
const {response} = error;
let message = 'Ops. Algo de errado aconteceu...';
if([401].indexOf(response.status) > -1){
localforage.removeItem('token');
router.push({
name: 'login'
});
Vue.notify({
group: 'panel',
type: 'error',
duration: 5000,
text: response.data.message ? response.data.message : message
});
}
return Promise.reject(error);
})
}
另外请注意,您可以将fetchData
函数简化为:
const actions = {
fetchData({commit, dispatch}) {
const config = {
_uuid: uuid()
}
const calls = [
'channels',
'conversations',
'events/actions'
].map(call => http.get(call, config))
// 20 more functions calls
axios.all(calls).then(axios.spread(function (channels, contacts, eventActions) {
dispatch('channels/setChannels', channels.data, {root: true})
dispatch('contacts/setContacts', contacts.data, {root: true})
dispatch('events/setActions', eventActions.data, {root: true})
}))
}
}
作为Axios取消的替代方案,您可以使用更简单的Bluebird Promise Cancellation。
与旧取消相比,新取消的优点是:
- .cancel()是同步的。
- 取消工作不需要设置代码
- 与其他蓝鸟功能组合,如Promise.all
这是一个演示。我在axios.get(...).then(...)
中添加了一些日志记录,以跟踪每个调用是否完成。
注释掉行promises.forEach(p => p.cancel())
以验证没有取消,非错误调用将运行完成。
//for demo, check if fetch completes
const logCompleted = (res) => console.log(`Promise completed, '${res.config.url}'`)
function getChannels() {
return axios.get("https://reqres.in/api/users?page=1&delay=5").then(logCompleted)
}
function getContacts() {
return axios.get("https://reqres.in/api/users?page=2").then(logCompleted)
}
function getEventActions() {
return axios.get("https://httpbin.org/status/401").then(logCompleted)
}
Promise.config({ cancellation: true }); // Bluebird config
window.Promise = Promise; // axios promises are now Bluebird flavor
const promises = [getChannels(), getContacts(), getEventActions()];
Promise.all(promises)
.then(([channels, contacts, eventActions]) => {
console.log('Promise.all.then', { channels, contacts, eventActions });
})
.catch(err => {
console.log(`Promise.all.catch, '${err.message}'`)
promises.forEach(p => p.cancel());
})
.finally(() => console.log('Promise.all.finally'))
<script src="https://cdnjs.cloudflare.com/ajax/libs/axios/0.18.0/axios.min.js"></script>
<script src="https://cdn.jsdelivr.net/bluebird/latest/bluebird.core.min.js"></script>
Promise.all()而不是axios.all()
看看这个老axios问题Remove axios.all
and axios.spread
#1042可以看到
Axios在引擎盖下使用Promise.all ......
还有这个
axios.all([getUserAccount(), getUserPermissions()])
.then(axios.spread(function (acct, perms) {
// Both requests are now complete
}));
可以用这个代替
Promise.all([getUserAccount(), getUserPermissions()])
.then(function ([acct, perms]) {
// Both requests are now complete
});
所以我们可以直接切换到与Promise一起使用,并且仍然具有相同的功能。
承诺失败很快
从MDN我们看到
如果任何元素被拒绝,Promise.all将被拒绝。例如,如果传入四个在超时后解析的promise和一个立即拒绝的promise,则Promise.all将立即拒绝。
所以在这种模式中
Promise.all(...)
.then(...)
.catch(...);
当第一个承诺失败时,.catch()
将触发(与then()
相反,等待所有承诺完成)。
组成Promise.all
和.cancel()
模式非常简单,只需取消.catch()
中的所有承诺(在第一次错误时调用)。
有关详细信息,请参阅此问题Stop other promises when Promise.all() rejects
在Vue商店代替Bluebird
这是Vuex中的基本实现。
yarn add bluebird
import Vue from "vue";
import Vuex from "vuex";
import axios from "axios";
import Promise from 'bluebird';
Vue.use(Vuex);
Promise.config({ cancellation: true }); // Bluebird config
window.Promise = Promise; // axios promises are now Bluebird flavor
export default new Vuex.Store({
actions: {
fetchData({ dispatch }) {
function getChannels() {
return axios.get("https://reqres.in/api/users?page=1&delay=5");
}
function getContacts() {
return axios.get("https://reqres.in/api/users?page=2");
}
function getEventActions() { // 401 - auth error
return axios.get("https://httpbin.org/status/401");
}
const promises = [getChannels(), getContacts(), getEventActions()];
Promise.all(promises)
.then(([channels, contacts, eventActions]) => {
dispatch("channels/setChannels", channels.data, { root: true });
dispatch("contacts/setContacts", contacts.data, { root: true });
dispatch("events/setActions", eventActions.data, { root: true });
})
.catch(err => {
promises.forEach(p => p.cancel());
})
}
}
});
upvoted answer提出了一个解决方案,需要等待所有响应完成,对uuid
的依赖,以及拦截器的一些复杂性。我的解决方案避免了所有这些并解决了终止Promise.all()
执行的目标。
Axios支持request cancelation,因此您可以使用错误处理程序包装GET
请求,该处理程序立即取消其他待处理请求:
fetchData({ dispatch }) {
const source = axios.CancelToken.source();
// wrapper for GET requests
function get(url) {
return axios.get(url, {
cancelToken: source.token // watch token for cancellation
}).catch(error => {
if (axios.isCancel(error)) {
console.warn(`canceled ${url}, error: ${error.message}`)
} else {
source.cancel(error.message) // mark cancellation for all token watchers
}
})
}
function getChannels() {
return get('https://reqres.in/api/users?page=1&delay=30'); // delayed 30 secs
}
function getContacts() {
return get('https://reqres.in/api/users?page=2'); // no delay
}
function getEventActions() {
return get('https://httpbin.org/status/401'); // 401 - auth error
}
...
}
在您的拦截器中,您还会忽略请求取消中的错误:
export default (http, store, router) => {
http.interceptors.response.use(
response => response,
error => {
if (http.isCancel(error)) {
return Promise.reject(error)
}
...
// show notification here
}
}