如何在React的组件范围之外使用React的上下文API:ReactJS [英] How to use React's context API outside of react's component scope : ReactJS
问题描述
我正在使用react的上下文API来存储USER_TOKEN以进行身份验证。
I am using react's context API for storing USER_TOKEN for authentication purposes.
我还在一个单独的模块中维护一个通用的提取函数,我想在其中使用此USER_TOKEN 。
Also I am maintaining a common fetch function in a separate module where I want to use this USER_TOKEN.
很明显,我不能在此模块内使用此USER_TOKEN,因为它不是React组件。
And Its obvious that I cannot use this USER_TOKEN inside this module as it is not a react component.
有什么办法可以在此提取函数中使用此USER_TOKEN。
Is there any way I can use this USER_TOKEN inside this fetch function.
成功登录后,我将USER_TOKEN存储到上下文API变量中。是的,我知道只要调用此函数,就可以从上下文传递变量。但问题是,未来的任何变化都必须在所有地方进行改变。所以我想知道是否只有一个地方可以做到这一点。基本上,这个想法是与所有API请求一起发送此令牌,因此尝试维护一个公共位置。
I am storing USER_TOKEN into a context API variable after successful sign-in. Yes I know we could pass the variable from context whenever we call this function. But the thing is , Any change in the future will have to change it in all places. So I was wondering If there is only one place where I can do this. Basically the idea is sending this token along with all the API requests, so trying to maintain a common place.
我们将不胜感激
export module FetchModule {
export async function fetch(obj: any) {
let url = obj.url;
let type = obj.type ? obj.type.toUpperCase() : "GET";
let options: any = {};
options.method = type;
let idToken = obj.token;// Want to retrieve this USER_TOKEN from react's context API
if (idToken) {
options.headers["USER_TOKEN"] = idToken;
}
options.headers = { ...options.headers, ...obj.headers };
const response = await fetch(url, options);
return await response.json();
}
}
推荐答案
- 在src / components文件夹中创建一个名为:Context的文件夹
- 在已创建的该文件夹中(Context)创建一个名为index.js的文件
- 在index.js文件中写入:
import React, { Component } from 'react';
const AppContext = React.createContext();
export class Provider extends Component {
state = {
token: ''
};
setToken = (token) => {
this.state.token = token;
this.setState();
};
render() {
return (
<AppContext.Provider value = {{
token: this.state.token,
actions: {
setToken: this.setToken
}
}}>
{this.props.children}
</AppContext.Provider>
);
}
}
exoprt const Consumer = AppContext.Consumer;
export const AppContextObject = AppContext;
- :
import React from 'react';
import ReactDOM from 'react-dom';
import { Provider } from "./compomemts/Context/";
import App from './App';
ReactDOM.render(
<Provider>
<App />
</Provider>
, document.getElementById("root")
);
- 假设您有登录组件,在其中写下:
import React, { PureComponent } from 'react';
import { Consumer, AppContextObject } from "../Context";
class Login extends PureComponent {
render() {
return (
<Consumer>
{(actions, token) => (
<button className="enter" id="enter-id" onClick={(event) => {
if(token === undifined) {
newToken = 'get the token from your system';
actions.setToken(newToken);
}
}} >
connect
</button>
)}
</Consumer>
)
}
}
Login.contextType = AppContextObject; // This part is important to access context values
SuperAdminContextObject
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