Meteor和react地图返回未定义，我知道数据在那里，但它加载了，尽管等待isLoading

Question

我有以下代码，将LeadBuilder道具传递给LeadBuilderSingle组件中的lead。它在一个对象中有一个数组，我访问该数组并试图映射到它上，但它返回未定义的结果。数据正在等待中，我正在使用isLoading，所以我不确定是什么导致了这个错误。它在第一次加载时加载，但在页面刷新时未定义。

import React, { useState, useEffect } from "react";
import Dasboard from "./Dashboard";
import { Container } from "../styles/Main";
import { LeadsBuilderCollection } from "../../api/LeadsCollection";
import { LeadBuilderSingle } from "../leads/LeadBuilderSingle";
import { useTracker } from "meteor/react-meteor-data";
const LeadCategoriesAdd = ({ params }) => {
const { leadsBuilder, isLoading } = useTracker(() => {
const noDataAvailable = { leadsBuilder: [] };
if (!Meteor.user()) {
return noDataAvailable;
}
const handler = Meteor.subscribe("leadsBuilder");
if (!handler.ready()) {
return { ...noDataAvailable, isLoading: true };
}
const leadsBuilder = LeadsBuilderCollection.findOne({ _id: params._id });
return { leadsBuilder };
});
return (
<Container>
<Dasboard />
<main className="">
{isLoading ? (
<div className="loading">loading...</div>
) : (
<>
<LeadBuilderSingle key={params._id} lead={leadsBuilder} />
</>
)}
</main>
</Container>
);
};
export default LeadCategoriesAdd;

import React from "react";
export const LeadBuilderSingle = ({ lead, onDeleteClick }) => {
console.log(lead);
return (
<>
<li>{lead.type}</li>
{lead.inputs.map((input, i) => {
return <p key={i}>{input.inputType}</p>;
})}
</>
);
};

FlowRouter.route("/leadCategories/:_id", {
name: "leadeBuilder",
action(params) {
mount(App, {
content: <LeadCategoriesAdd params={params} />,
});
},
});

Answer 1

试试这个：

lead.inputs && lead.inputs.map ((input, i) => {...}