javascript - 循环遍历 fetch() 调用列表

Question

我正在尝试循环处理一堆数据并进行异步调用。但是，我的语法不正确

async function getEmailData(conversationId){
    fetch(aysynch)
    .then(response => {return response.json(); })
    .then(data => {
        dictionary = {}
        console.log(data)
        var info = data.Body.ResponseMessages.Items[0].Conversation.ConversationNodes[0].Items[0]
        console.log(info)
        var conversationId = info.ConversationId.Id
        var from = info.From.Mailbox.EmailAddress
        var to = info.ToRecipients.map(function(recipient) {return recipient.EmailAddress})
        var date = info.DateTimeReceived
        dictionary[conversationId] = {'from':from, 'to': to, 'date': date}
        return dictionary
    })
}

x = [listOfIds] //10 in total

for (i=0; i<x.length; i++) {
    console.log(x[i].ConversationId.Id)
    let response = await getEmailData(x[i].ConversationId.Id)
    let data = await response
    console.log(data)
}

这是打印出所有 ID，然后获取 x 中的列表 ID 并运行该 ID 10 次。如何为每个请求发出 aysnch 请求？

Answer 1

一些问题:

• 函数getEmailData没有返回任何内容。您需要返回 promise 链的结果。
• 如果您不在此类函数内使用 await，async 就没有任何用处
• async 函数外部的 await 无效。
当 response 已经是 await 的结果时，
• await response 没有用处
• 声明变量(使用 let、var、const)

所以这样做:

function getEmailData(conversationId){
    return fetch(aysynch)
    .then(response => response.json())
    .then(data => {
        const dictionary = {};
        console.log(data);
        var info = data.Body.ResponseMessages.Items[0].Conversation.ConversationNodes[0].Items[0];
        console.log(info);
        var conversationId = info.ConversationId.Id;
        var from = info.From.Mailbox.EmailAddress;
        var to = info.ToRecipients.map(recipient => recipient.EmailAddress);
        var date = info.DateTimeReceived;
        dictionary[conversationId] = {from, to, date};
        return dictionary;
    });
}

(async function() {
    let x = [1, 2, 4, 6, 9, 13, 23, 22, 24, 19]; //10 in total

    for (let i=0; i<x.length; i++) {
        console.log(x[i].ConversationId.Id);
        let data = await getEmailData(x[i].ConversationId.Id);
        console.log(data);
    }
})(); // Immediately invoked