我发送了一些 http 请求,在 Promises 解决之后,我需要循环遍历数组并执行一些异步操作。我想让函数异步,但我需要仅在“map”循环完成后执行 setState:
fetchData = () => {
let data = [];
let tickets = http.get('/api/zendesk/tickets'),
users = http.get('/api/zendesk/users'),
items = http.get('/api/orders/items'),
reqTypes = http.get("/api/support/requests");
Promise.all([users,tickets,items,reqTypes])
.then(values => {
console.log(values);
let usersArr = values[0].data.users,
ticketsArr = values[1].data.tickets,
itemsArr = values[2].data,
requestArr = values[3].data;
data = ticketsArr.map((ticket,key) => {
let id = ticket.custom_fields.find(field => field.id === productions_fields.order_id || field.id === develop_fields.order_id).value;
id === null ? ticket.Items = [] : ticket.Items = itemsArr.filter(item => item.order_id === parseInt(id));
ticket.Requests = requestArr.filter(request => request.id === ticket.id);
})
this.setState({tickets:data})
}).catch(err => console.log(err))
}
最佳答案
I get an array of "undefined objects", Why?
因为您没有在 map 主体内返回任何内容,并且默认情况下它返回未定义
。
检查此片段:
let a = [1,2,3,4].map(el => {
console.log('el = ', el);
})
console.log('a = ', a); //array of undefined values
如果要修改现有数组,请使用 forEach
而不是 map
。
像这样:
ticketsArr.forEach((ticket,key) => {
let id = ticket.custom_fields.find(field => field.id === productions_fields.order_id || field.id === develop_fields.order_id).value;
ticket.Items = (id === null) ? [] : itemsArr.filter(item => item.order_id === parseInt(id));
ticket.Requests = requestArr.filter(request => request.id === ticket.id);
})
this.setState({ tickets: ticketsArr })
关于javascript - 如何仅在 "map"循环完成时设置状态?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/48609078/