我有一个非常基本的单页应用程序，当我单击以创建新实例时，控制台中显示Sample Data
=============
Users
------------------
user_id, user_name
------------------
1, User_A
2, User_B
3, User_C
Books
------------------
book_id, book_name
------------------
1, Book_A
2, Book_B
3, Book_C
Users_Books
-----------------------------------
assigned_date, user_id, book_id
-----------------------------------
01-01-2020, 1, 1
02-01-2020, 1, 2
03-01-2020, 1, 3
04-01-2020, 2, 1
05-01-2020, 3, 1
06-01-2020, 4, 1
Sample Output
==============================
user_id, user_name, json_col
------------------------------
1, User_A, (See Json Output below for this row)
2, User_B
3, User_C
[{
"assigned_date": "01-01-2020",
"user_id": "1",
"book_id": "1",
"book_detail": {
"book_id": "1",
"book_name": "Book_A"
}
}, {
"assigned_date": "02-01-2020",
"user_id": "1",
"book_id": "2",
"book_detail": {
"book_id": "2",
"book_name": "Book_B"
}
}, {
"assigned_date": "03-01-2020",
"user_id": "1",
"book_id": "3",
"book_detail": {
"book_id": "3",
"book_name": "Book_C"
}
}]
。当我刷新页面时，将显示新实例。
Uncaught (in promise) TypeError: Cannot read property 'attributes' of undefined我有一个使用带有属性的序列化器的Ruby On Rails后端
function postFetch(name, description, image_url, event_id) {
const bodyData = {name, description, image_url, event_id}
fetch(endPoint, {
method: "POST",
headers: {"Content-Type": "application/json"},
body: JSON.stringify(bodyData)
})
.then(response => response.json())
.then(hike => {
console.log(hike);
const hikeData = hike.data
let newHike = new Hike(hikeData, hikeData.attributes)
document.querySelector('#hike-container').innerHTML += newHike.renderHikeCard()
})
这是我第一次发布。抱歉，如果这样做没有意义。我是编码的新手，却卡在此错误上。任何帮助将不胜感激。