Reputation: 2334
You can see what I've done here.
import "babel-polyfill";
import React from "react";
import ReactDOM from "react-dom";
const asyncFunc = () => {
return new Promise(resolve => {
setTimeout(resolve("Gotcha!!!"), 10000);
});
};
class App extends React.Component {
state = {
text: "Fetching..."
};
componentDidMount = async () => {
const text = await asyncFunc();
this.setState({ text });
};
render() {
return <div className="App">{this.state.text}</div>;
}
}
The app should show Fetching...
first, then shows Gotcha!!!
after 10 seconds. But, it's not working. What's my mistake?
Upvotes: 2
Views: 7076
Reputation: 1899
import "babel-polyfill";
import React from "react";
import ReactDOM from "react-dom";
import "./styles.css";
const asyncFunc = () => {
return new Promise(resolve => {
setTimeout(() => resolve("Gotcha!!!"), 10000);
});
};
class App extends React.Component {
constructor() {
super();
this.state = {
text: "Fetching..."
};
}
componentDidMount = async () => {
const newText = await asyncFunc();
this.setState({ text: newText });
};
render() {
return <div className="App">{this.state.text}</div>;
}
}
const rootElement = document.getElementById("root");
ReactDOM.render(<App />, rootElement);
Upvotes: 1
Reputation: 370729
The problem is:
setTimeout(resolve("Gotcha!!!"), 10000);
The first argument to setTimeout
should be a function. At the moment, you're calling resolve
immediately as setTimeout
tries to resolve its arguments (synchronously). Instead, pass it a function that then calls resolve
:
setTimeout(() => resolve("Gotcha!!!"), 10000);
or
setTimeout(resolve, 10000, "Gotcha!!!");
Upvotes: 5
Reputation: 2111
You need to pass setTimeout
a callback function, change it to this
setTimeout(() => resolve("Gotcha!!!"), 10000);
Upvotes: 1