Meteor语言 - 在 Tracker.autorun 函数中返回，不返回任何内容

Question

函数renderNotes()应该返回位于单独文件中的映射数组。 我注意到当我返回一些JSX时，没有任何内容返回屏幕。 我想我知道原因是因为它将信息返回到跟踪器功能。 在 tracker.autorun(( 函数中，我如何获取信息以返回到renderNotes()函数？

import { Meteor } from "meteor/meteor";
import React from "react";
import { withRouter, Link } from "react-router-dom";
import { Accounts } from "meteor/accounts-base";
import { Tracker } from "meteor/tracker";
import SubjectRoutes from "./subjectRoutes/subjectRoutes";
import { Notes } from "../methods/methods"
import Menu from "./Menu.js";
class Home extends React.Component{
componentWillMount() {
if(!Meteor.userId()){
this.props.history.replace("/login")
}
}
logoutUser(e){
e.preventDefault()
Accounts.logout(() => {
this.props.history.push("/login");
});
}
renderNotes(){
Tracker.autorun(function () {
Meteor.subscribe('notes');
let notes = Notes.find().fetch();
// return notes.map((note) => {
//   return <p>{note.imageURL}</p>
// })
return <p>asdas</p> //<--Here
});
}
render(){
return (
<div>
<button onClick={this.logoutUser.bind(this)}>Logout</button>
{this.renderNotes()}
<Menu />
</div>
)
}
}
export default withRouter(Home);

Answer 1

不知道这是否是一个正确的答案，但我喜欢通常做这样的事情

import TrackerReact from 'meteor/ultimatejs:tracker-react';
import { Notes } from "../methods/methods";
export default class Home extends TrackerReact(React.Component) {
constructor(props,) {
super(props);
this.state = {
subscription:{
publishNotes: Meteor.subscribe("publish-Notes")
}
};
}
returnNotes(){
return Notes.find().fetch();
}
render(){
...
const stuff = this.returnNotes().map((note)=>{
return <p>{note}</p>
});
return (
....
{stuff}
)
}
}

Answer 2

这对我有用：

import { Meteor } from "meteor/meteor";
import React from "react";
import { withRouter, Link } from "react-router-dom";
import { Accounts } from "meteor/accounts-base";
import { Tracker } from "meteor/tracker";
import SubjectRoutes from "./subjectRoutes/subjectRoutes";
import { Notes } from "../methods/methods"
import Menu from "./Menu.js";
class Home extends React.Component{
constructor(props){
super(props)
this.state = {
notes: []
}
}
componentWillMount() {
if(!Meteor.userId()){
this.props.history.replace("/login")
}
this.tracker = Tracker.autorun(()=>{
Meteor.subscribe('notes');
let notes = Notes.find().fetch();
this.setState({ notes })
});
}
componentWillUnmount() {
this.tracker.stop();
}
logoutUser(e){
e.preventDefault()
Accounts.logout(() => {
this.props.history.push("/login");
});
}
renderNotes(notes){
return notes.map((note) => {
return (
<div key={note._id}>
<img src={note.imageURL} />
<p>{note.type}</p>
</div>
)
});
}
render(){
return (
<div>
<button onClick={this.logoutUser.bind(this)}>Logout</button>
<Menu />
{this.renderNotes(this.state.notes)}
</div>
)
}
}
export default withRouter(Home);