I used react-router to define the following routes:
<Route
path="/plan"
components={App}
>
<Route
path="try/:planCategory"
components={PlanTrialContainer}
/>
<Route
path="pay/:planCategory"
components={PlanPurchaseContainer}
/>
</Route>
The idea is that: when a user visits url /plan, he will see a plan overview by default, otherwise the content will be decided by try/... or pay/...
Here is the App class
import React, { Component } from 'react';
import { Menu } from './Menu';
import PlansOverviewContainer from './PlansOverviewContainer';
export default class App extends Component {
render() {
const { children } = this.props.children;
let component = null;
if (children) {
component = children;
} else {
component = PlansOverviewContainer;
}
return (
<div>
<Menu />
{component}
</div>
);
}
}
I will get this error message when I try the /plan
TypeError: Cannot read property 'children' of null
App.render
/Users/antkong/dev/myproject/plan/app/scripts/components/App.js
If I change the line from
const { children } = this.props.children;
to
const children = this.props ? this.props.children : null;
It will work.
However my preferred version is the first version i.e. this.props should be initialised no matter what. How can I ensure prop is initialised? Is there any parameter to the Router component I can use?
You are destructuring children from this.props.children which is like trying to do:
this.props.children.children
Instead change it to:
const { children } = this.props;
You need to call the super-classes initializer like so:
import React, { Component } from 'react';
import { Menu } from './Menu';
import PlansOverviewContainer from './PlansOverviewContainer';
export default class App extends Component {
constructor(props) {
super(props);
}
render() {
const { children } = this.props.children;
let component = null;
if (children) {
component = children;
} else {
component = PlansOverviewContainer;
}
return (
<div>
<Menu />
{component}
</div>
);
}
}
Related
I'm trying to load a details view based on a react-router-dom route that should grab the URL parameter (id) and use that to further populate the component.
My route looks like /task/:id and my component loads fine, until I try to grab the :id from the URL like so:
import React from "react";
import { useParams } from "react-router-dom";
class TaskDetail extends React.Component {
componentDidMount() {
let { id } = useParams();
this.fetchData(id);
}
fetchData = id => {
// ...
};
render() {
return <div>Yo</div>;
}
}
export default TaskDetail;
This triggers the following error and I'm unsure where to correctly implement useParams().
Error: Invalid hook call. Hooks can only be called inside of the body of a function component.
The docs only show examples based on functional components, not class based.
Version <= 5:
You can use withRouter to accomplish this. Simply wrap your exported classed component inside of withRouter and then you can use this.props.match.params.id to get the parameters instead of using useParams(). You can also get any location, match, or history info by using withRouter. They are all passed in under this.props
Using your example it would look like this:
import React from "react";
import { withRouter } from "react-router";
class TaskDetail extends React.Component {
componentDidMount() {
const id = this.props.match.params.id;
this.fetchData(id);
}
fetchData = id => {
// ...
};
render() {
return <div>Yo</div>;
}
}
export default withRouter(TaskDetail);
Simple as that!
import React, { Component } from "react";
import { useParams } from "react-router-dom";
function withParams(Component) {
return props => <Component {...props} params={useParams()} />;
}
class TaskDetail extends React.Component {
componentDidMount() {
let { id } = this.props.params;
this.fetchData(id);
}
fetchData = id => {
// ...
};
render() {
return <div>Yo</div>;
}
}
export default withParams(TaskDetail);
Since hooks wont work with class based components you can wrap it in a function and pass the properties along:
class TaskDetail extends React.Component {
componentDidMount() {
const { id } = this.props.params;
// ...
}
}
export default (props) => (
<TaskDetail
{...props}
params={useParams()}
/>
);
But, like #michael-mayo said, I expect this is what withRouter is already performing.
Params get passed down through props on the match object.
props.match.params.yourParams
source: https://redux.js.org/advanced/usage-with-react-router
Here is an example from the docs destructing the props in the arguments.
const App = ({ match: { params } }) => {
return (
<div>
<AddTodo />
<VisibleTodoList filter={params.filter || 'SHOW_ALL'} />
<Footer />
</div>
)
}
You can not call a hook such as "useParams()" from a React.Component.
Easiest way if you want to use hooks and have an existing react.component is to create a function then call the React.Component from that function and pass the parameter.
import React from 'react';
import useParams from "react-router-dom";
import TaskDetail from './TaskDetail';
function GetId() {
const { id } = useParams();
console.log(id);
return (
<div>
<TaskDetail taskId={id} />
</div>
);
}
export default GetId;
Your switch route will still be something like
<Switch>
<Route path="/task/:id" component={GetId} />
</Switch>
then you will be able to get the id from from the props in your react component
this.props.taskId
In react-router-dom-v6 you can easily use useParams() in functional components but when it gets to the class component you have to create HOC (higher-order component) because hooks don't support class components:
import { useNavigate, useParams } from "react-router-dom";
export const withRouter = (WrappedComponent) => (props) => {
const params = useParams();
const navigate = useNavigate();
return <WrappedComponent {...props} params={params} navigate={navigate} />;
};
Then export your component from your HOC and give your component as a parameter. like below:
export default withRouter(YourComponentName);
After that you can easily access the url id with this.props.params.id and you can navigate to other components with this.props.navigate("/YourPath")
React Route v5
Query params can be read and processed as JSON using withRouter and queryString as follow:
import React from "react";
import { withRouter } from "react-router";
import queryString from 'query-string';
class MyComponent extends React.Component {
componentDidMount() {
const params = queryString.parse(this.props.location.search);
console.log('Do something with it', params);
}
render() {
return <div>Hi!</div>;
}
}
export default withRouter(MyComponent);
SmujMaiku is rigth!!! His answer works perfectly. This is how work today with react-router v6
enter code here
import React ,{Component} from 'react'
import { useParams } from "react-router-dom";
import PokeDescription from '../components/PokeDescription'
class PokeInfoConteiner extends Component{
render(){
let urlPokemon= "https://raw.githubusercontent.com/PokeAPI/sprites/master/sprites/pokemon/"
const {idPokemon} = this.props.params
console.log(idPokemon)
return(
<div>
<PokeDescription pokeImage={`${urlPokemon}${idPokemon}.png?raw=true`}/>
<p>{}</p>
</div>
)
}
}
export default (props) => (
<PokeInfoConteiner
{...props}
params={useParams()}
/>)
in React Router V6 :
import React, {Component} from 'react';
import {useParams} from 'react-router-dom';
/* This is a higher order component that
* inject a special prop to our component.
*/
function withRouter(Component) {
function ComponentWithRouter(props) {
let params = useParams()
return <Component {...props} params={params} />
}
return ComponentWithRouter
}
class TaskDetail extends React.Component {
state={
id : ""
}
componentDidMount() {
this.setState({
id : this.props.params.id
})
}
static getDerivedStateFromProps(nextProps) {
return {
id : nextProps.params.id
}
}
fetchData = id => {
// ...
};
render() {
return <div>Yo</div>;
}
}
const HOCTaskDetail = withRouter(TaskDetail);
export default HOCTaskDetail;
React Route v6
My friends, I tried to use in class but I failed to find any doc about it. So after many hours of searching and trying hard this is (in function). Now (i.e when I'm writing this post) there is only limited resource about v6. But there are many for <v6.
Here I'm using useState,useEffect,useParams,axios.
import React, { useState, useEffect } from 'react';
import { useParams } from 'react-router-dom';
import axios from 'axios';
const Post = () => {
let { post_id } = useParams();
const [posts, setPosts] = useState({ post: null, countSecrets: 0, ui: '' });
useEffect(() => {
if (posts.countSecrets === 0) {
const doAxe = (a) => {
axios.get('https://jsonplaceholder.typicode.com/posts/' + post_id)
.then((res) => {
setPosts(s => ({ ...s, value: res.data }));
doUI(res.data)
// console.log(res.data)
});
}
setPosts(s => ({ ...s, countSecrets: s.countSecrets + 1 }));
doAxe()
}
}, [posts, post_id]);
let doUI = (x) => {
// console.log('x' + x.title)
const finalPost = (x !== null) ? (
<div className="post">
<h4 className="center">{x.title}</h4>
<p>{x.body}</p>
</div>
) : (
<div className="center">Loading posts...</div>
);
setPosts(s => ({ ...s, ui: finalPost }));
}
return (
<div className="container">
{posts.ui}
</div>
);
}
export default Post;
NOTE:
I faced useEffect looping. I prevented it with a key.
HOPE: This may help someone!
Reference:
using useParams
state inside function
preventing loop from useEffect
In react-router-dom v6, there is no hook such as withRouter therefore my advice to you is to convert your class-based component to a functional component to use useParams hook in your component otherwise you can create a higher-order component to pass your class-based component.
as you know the useParams() is a hook for react-router-dom.
you can not use this inside the componentDidMount() or useEffect() because both of them are method that called during the Mounting phase of the React Life-cycle i.e after the component is rendered.
you have a solution:
create or define another function outside the componentDidMount() to define useParams then call it inside the componentDidMount.
know every thing will be ok.
This is my working example. :)
import React, { Component } from "react";
import { useParams } from "react-router-dom";
function withParams(Component) {
return (props) => <Component {...props} params={useParams()} />;
}
class ProductDetails extends Component {
handleSave = () => {
// Navigate to /products
};
render() {
return (
<div>
<h1>Product Details - {this.props.params.id}</h1>
<button onClick={this.handleSave}>Save</button>
</div>
);
}
}
export default withParams(ProductDetails);
Hooks only work on functional components,
you have to make that ocmponent a functional component
Fixed by creating a wrapping function
I needed to pass params to my SaxjaxApp.js from index.js using react-router-dom v6.
In v6 Switch has been changed to Routes
I got the useParams working with a class component by following Mohamed MAZEK's idea in post 20 using a wrapping function.
I needed to access the sessionId part of the url when it was available.
ie in localhost:3000/shared/123XYZId
I needed the 123XYZId part.
make note of this line : <Route path="/shared/:sessionId" element={<SaxjaxAppWrapper />} /> in the index.js below.
:sessionId denotes that useParams has a property called sessionId, that can be accessed by:
const {sessionId} = useParams() from a functional component.
In my index.js file I did this:
import React from "react";
import ReactDOM from "react-dom/client";
import { BrowserRouter, Route, Routes } from "react-router-dom";
import "./styles/style.scss";
import SaxjaxAppWrapper from "SaxjaxAppWrapper";
import SaxjaxApp from "./SaxjaxApp";
const container = document.getElementById("root");
const root = ReactDOM.createRoot(container);
//INFO: to learn about react-roue-dom v6 https://reactrouter.com/en/v6.3.0/upgrading/v5
root.render(
// <React.StrictMode>
<BrowserRouter>
<Routes>
<Route path="/shared/:sessionId" element={<SaxjaxAppWrapper />} />
<Route path="/" element={<SaxjaxApp />} />
</Routes>
</BrowserRouter>
// </React.StrictMode>
);
This line <Route path="/shared/:sessionId" element={<SaxjaxAppWrapper />} /> calls my wrapping function, whereas the default path / just calls the class component.
I had to create a separate file to hold the wrapping function I don't know why:
import React from "react";
import { useParams } from "react-router-dom";
import SaxjaxApp from "SaxjaxApp";
function SaxjaxAppWrapper() {
//I use the params here and store them to pass as props
let { sessionId } = useParams();
return (
//I pass the sessionId from the url params as a prop to my SaxjaxApp class component here
<SaxjaxApp sessionId={sessionId} />
);
}
export default SaxjaxAppWrapper;
My class component:
import React, { Component } from "react";
import "./styles/style.scss";
class SaxjaxApp extends Component {
state = {
octave: 4,
};
constructor(props) {
super(props);
//... initialise stuff
}
//... a lot of methods
render() {
//Access the param here
const { sessionId } = this.props;
<>
<div>
keybordId={sessionId ? sessionId : "no id was passed"}
</div>
</>
);
}
}
export default SaxjaxApp;
I'm using Auth0, and can grab the data using hooks like so:
const { user } = useAuth0()
How can I refactor and get that same data in a Class Component? I just cannot figure it out or find a good example. I've tried:
this.state = { user: useAuth0()}
But no luck...
auth0-react provides a HOC withAuth0 which you can use with class components as mentioned here
import React, { Component } from 'react';
import { withAuth0 } from '#auth0/auth0-react';
class Profile extends Component {
render() {
// `this.props.auth0` has all the same properties as the `useAuth0` hook
const { user } = this.props.auth0;
return <div>Hello {user.name}</div>;
}
}
export default withAuth0(Profile);
Wrapper function component outside class component;
const AuthWrapper = (E)=> {
const WrapperComponent = (props)=> {
const { user } = useAuth0()
return <E user={user} {...props} />
}
return WrapperComponent;
}
Class Component
#AuthWrapper
class AuthDemo extends Component {
render() {
const { user } = this.props;
...
}
}
you need to use higher order component to implements.
more details: use-with-a-class-component
In React can methods be passed to {this.children} in a container consumer model. What I mean to ask is I have a provider component and I need to pass or refer the provider components methods in the child component.
export default class ContainerCompo extends React.Component {
constructor(props) {
super(props);
this.myHocComponent = null;
}
methodOne() {
//some code
}
methodTwo() {
//some code
}
render() {
return (
{this.props.children}
}
}
export default class InputComponent extends React.Component {
constructor(props) {
super(props);
this.myHocComponent = null;
}
validate() {
ContainerCompo.methodOne(param)
}
render() {
return <InputComponent />
}
// Rendering the components
<ContainerCompo>
<InputComponent containerMethods={methods of ContainerCompo}/>
</ContainerCompo>
I hope my question is clear here, please suggest
First create a react context.
import React, { Component, createContext } from 'react';
// Create's authentication context to be use anywhere in the app
const ContainerContext = createContext();
export default ContainerContext;
Then create a provider for it.
export default class ContainerProvider extends Component {
constructor(props) {
super(props);
this.myHocComponent = null;
}
methodOne() {
//some code
}
methodTwo() {
//some code
}
render() {
const { children } = this.props;
return (
<ContainerContext.Provider
value={{
container: {
methodOne: (...params) => this.methodOne(...params),
methodTwo: (...params) => this.methodTwo(...params)
}
}}
>
{children}
</ContainerContext.Provider>
)}}
Wrap your App with the provider.
import ContainerProvider from './ContainerProvider'
<ContainerProvider>
<App />
</ContainerProvider>
Then create a consumer for the context
export default function withContainer(InComponent) {
return function ContainerComponent(props) {
return (
<ContainerContext.Consumer>
{({ container }) => <InComponent {...props} container={container} />}
</ContainerContext.Consumer>
);
};
}
Then import the consumer and user in your components and you will get the methods as props
import withContainer from './ContainerConsumer'
render() {
const { container } = this.props;
return(<div />)
}
export default withContainer(YourComponent);
I'm trying to load a details view based on a react-router-dom route that should grab the URL parameter (id) and use that to further populate the component.
My route looks like /task/:id and my component loads fine, until I try to grab the :id from the URL like so:
import React from "react";
import { useParams } from "react-router-dom";
class TaskDetail extends React.Component {
componentDidMount() {
let { id } = useParams();
this.fetchData(id);
}
fetchData = id => {
// ...
};
render() {
return <div>Yo</div>;
}
}
export default TaskDetail;
This triggers the following error and I'm unsure where to correctly implement useParams().
Error: Invalid hook call. Hooks can only be called inside of the body of a function component.
The docs only show examples based on functional components, not class based.
Version <= 5:
You can use withRouter to accomplish this. Simply wrap your exported classed component inside of withRouter and then you can use this.props.match.params.id to get the parameters instead of using useParams(). You can also get any location, match, or history info by using withRouter. They are all passed in under this.props
Using your example it would look like this:
import React from "react";
import { withRouter } from "react-router";
class TaskDetail extends React.Component {
componentDidMount() {
const id = this.props.match.params.id;
this.fetchData(id);
}
fetchData = id => {
// ...
};
render() {
return <div>Yo</div>;
}
}
export default withRouter(TaskDetail);
Simple as that!
import React, { Component } from "react";
import { useParams } from "react-router-dom";
function withParams(Component) {
return props => <Component {...props} params={useParams()} />;
}
class TaskDetail extends React.Component {
componentDidMount() {
let { id } = this.props.params;
this.fetchData(id);
}
fetchData = id => {
// ...
};
render() {
return <div>Yo</div>;
}
}
export default withParams(TaskDetail);
Since hooks wont work with class based components you can wrap it in a function and pass the properties along:
class TaskDetail extends React.Component {
componentDidMount() {
const { id } = this.props.params;
// ...
}
}
export default (props) => (
<TaskDetail
{...props}
params={useParams()}
/>
);
But, like #michael-mayo said, I expect this is what withRouter is already performing.
Params get passed down through props on the match object.
props.match.params.yourParams
source: https://redux.js.org/advanced/usage-with-react-router
Here is an example from the docs destructing the props in the arguments.
const App = ({ match: { params } }) => {
return (
<div>
<AddTodo />
<VisibleTodoList filter={params.filter || 'SHOW_ALL'} />
<Footer />
</div>
)
}
You can not call a hook such as "useParams()" from a React.Component.
Easiest way if you want to use hooks and have an existing react.component is to create a function then call the React.Component from that function and pass the parameter.
import React from 'react';
import useParams from "react-router-dom";
import TaskDetail from './TaskDetail';
function GetId() {
const { id } = useParams();
console.log(id);
return (
<div>
<TaskDetail taskId={id} />
</div>
);
}
export default GetId;
Your switch route will still be something like
<Switch>
<Route path="/task/:id" component={GetId} />
</Switch>
then you will be able to get the id from from the props in your react component
this.props.taskId
In react-router-dom-v6 you can easily use useParams() in functional components but when it gets to the class component you have to create HOC (higher-order component) because hooks don't support class components:
import { useNavigate, useParams } from "react-router-dom";
export const withRouter = (WrappedComponent) => (props) => {
const params = useParams();
const navigate = useNavigate();
return <WrappedComponent {...props} params={params} navigate={navigate} />;
};
Then export your component from your HOC and give your component as a parameter. like below:
export default withRouter(YourComponentName);
After that you can easily access the url id with this.props.params.id and you can navigate to other components with this.props.navigate("/YourPath")
React Route v5
Query params can be read and processed as JSON using withRouter and queryString as follow:
import React from "react";
import { withRouter } from "react-router";
import queryString from 'query-string';
class MyComponent extends React.Component {
componentDidMount() {
const params = queryString.parse(this.props.location.search);
console.log('Do something with it', params);
}
render() {
return <div>Hi!</div>;
}
}
export default withRouter(MyComponent);
SmujMaiku is rigth!!! His answer works perfectly. This is how work today with react-router v6
enter code here
import React ,{Component} from 'react'
import { useParams } from "react-router-dom";
import PokeDescription from '../components/PokeDescription'
class PokeInfoConteiner extends Component{
render(){
let urlPokemon= "https://raw.githubusercontent.com/PokeAPI/sprites/master/sprites/pokemon/"
const {idPokemon} = this.props.params
console.log(idPokemon)
return(
<div>
<PokeDescription pokeImage={`${urlPokemon}${idPokemon}.png?raw=true`}/>
<p>{}</p>
</div>
)
}
}
export default (props) => (
<PokeInfoConteiner
{...props}
params={useParams()}
/>)
in React Router V6 :
import React, {Component} from 'react';
import {useParams} from 'react-router-dom';
/* This is a higher order component that
* inject a special prop to our component.
*/
function withRouter(Component) {
function ComponentWithRouter(props) {
let params = useParams()
return <Component {...props} params={params} />
}
return ComponentWithRouter
}
class TaskDetail extends React.Component {
state={
id : ""
}
componentDidMount() {
this.setState({
id : this.props.params.id
})
}
static getDerivedStateFromProps(nextProps) {
return {
id : nextProps.params.id
}
}
fetchData = id => {
// ...
};
render() {
return <div>Yo</div>;
}
}
const HOCTaskDetail = withRouter(TaskDetail);
export default HOCTaskDetail;
React Route v6
My friends, I tried to use in class but I failed to find any doc about it. So after many hours of searching and trying hard this is (in function). Now (i.e when I'm writing this post) there is only limited resource about v6. But there are many for <v6.
Here I'm using useState,useEffect,useParams,axios.
import React, { useState, useEffect } from 'react';
import { useParams } from 'react-router-dom';
import axios from 'axios';
const Post = () => {
let { post_id } = useParams();
const [posts, setPosts] = useState({ post: null, countSecrets: 0, ui: '' });
useEffect(() => {
if (posts.countSecrets === 0) {
const doAxe = (a) => {
axios.get('https://jsonplaceholder.typicode.com/posts/' + post_id)
.then((res) => {
setPosts(s => ({ ...s, value: res.data }));
doUI(res.data)
// console.log(res.data)
});
}
setPosts(s => ({ ...s, countSecrets: s.countSecrets + 1 }));
doAxe()
}
}, [posts, post_id]);
let doUI = (x) => {
// console.log('x' + x.title)
const finalPost = (x !== null) ? (
<div className="post">
<h4 className="center">{x.title}</h4>
<p>{x.body}</p>
</div>
) : (
<div className="center">Loading posts...</div>
);
setPosts(s => ({ ...s, ui: finalPost }));
}
return (
<div className="container">
{posts.ui}
</div>
);
}
export default Post;
NOTE:
I faced useEffect looping. I prevented it with a key.
HOPE: This may help someone!
Reference:
using useParams
state inside function
preventing loop from useEffect
In react-router-dom v6, there is no hook such as withRouter therefore my advice to you is to convert your class-based component to a functional component to use useParams hook in your component otherwise you can create a higher-order component to pass your class-based component.
as you know the useParams() is a hook for react-router-dom.
you can not use this inside the componentDidMount() or useEffect() because both of them are method that called during the Mounting phase of the React Life-cycle i.e after the component is rendered.
you have a solution:
create or define another function outside the componentDidMount() to define useParams then call it inside the componentDidMount.
know every thing will be ok.
This is my working example. :)
import React, { Component } from "react";
import { useParams } from "react-router-dom";
function withParams(Component) {
return (props) => <Component {...props} params={useParams()} />;
}
class ProductDetails extends Component {
handleSave = () => {
// Navigate to /products
};
render() {
return (
<div>
<h1>Product Details - {this.props.params.id}</h1>
<button onClick={this.handleSave}>Save</button>
</div>
);
}
}
export default withParams(ProductDetails);
Hooks only work on functional components,
you have to make that ocmponent a functional component
Fixed by creating a wrapping function
I needed to pass params to my SaxjaxApp.js from index.js using react-router-dom v6.
In v6 Switch has been changed to Routes
I got the useParams working with a class component by following Mohamed MAZEK's idea in post 20 using a wrapping function.
I needed to access the sessionId part of the url when it was available.
ie in localhost:3000/shared/123XYZId
I needed the 123XYZId part.
make note of this line : <Route path="/shared/:sessionId" element={<SaxjaxAppWrapper />} /> in the index.js below.
:sessionId denotes that useParams has a property called sessionId, that can be accessed by:
const {sessionId} = useParams() from a functional component.
In my index.js file I did this:
import React from "react";
import ReactDOM from "react-dom/client";
import { BrowserRouter, Route, Routes } from "react-router-dom";
import "./styles/style.scss";
import SaxjaxAppWrapper from "SaxjaxAppWrapper";
import SaxjaxApp from "./SaxjaxApp";
const container = document.getElementById("root");
const root = ReactDOM.createRoot(container);
//INFO: to learn about react-roue-dom v6 https://reactrouter.com/en/v6.3.0/upgrading/v5
root.render(
// <React.StrictMode>
<BrowserRouter>
<Routes>
<Route path="/shared/:sessionId" element={<SaxjaxAppWrapper />} />
<Route path="/" element={<SaxjaxApp />} />
</Routes>
</BrowserRouter>
// </React.StrictMode>
);
This line <Route path="/shared/:sessionId" element={<SaxjaxAppWrapper />} /> calls my wrapping function, whereas the default path / just calls the class component.
I had to create a separate file to hold the wrapping function I don't know why:
import React from "react";
import { useParams } from "react-router-dom";
import SaxjaxApp from "SaxjaxApp";
function SaxjaxAppWrapper() {
//I use the params here and store them to pass as props
let { sessionId } = useParams();
return (
//I pass the sessionId from the url params as a prop to my SaxjaxApp class component here
<SaxjaxApp sessionId={sessionId} />
);
}
export default SaxjaxAppWrapper;
My class component:
import React, { Component } from "react";
import "./styles/style.scss";
class SaxjaxApp extends Component {
state = {
octave: 4,
};
constructor(props) {
super(props);
//... initialise stuff
}
//... a lot of methods
render() {
//Access the param here
const { sessionId } = this.props;
<>
<div>
keybordId={sessionId ? sessionId : "no id was passed"}
</div>
</>
);
}
}
export default SaxjaxApp;
How can I avoid writing the same code when two components share some same methods but have a different layout?
The sample components below have a method "renderLastItem" which uses prop "something" passed by the parent components.
I thought about using Higher Order Component Pattern but I'm not sure I I can pass props as an argument to Higher Order Component.
The sample code below is very simple, so in this sample code, I just need to use If statement and change the layout according to the type of components, but in real code, I have more codes and I want to avoid using if statement in order to change the layout according to the type of a component.
How can I avoid writing the same logic in multiple components?
ComponentA
import React, { Component } from 'react';
import PropTypes from 'prop-types';
const propTypes = {};
const defaultProps = {};
class SampleA extends Component {
constructor(props) {
super(props);
}
renderLastItem() {
if(!this.props.something) {
return null;
}
return this.props.something[this.props.something.length - 1];
}
render() {
return (
<div>
<h1>Something</h1>
<p>{this.renderLastItem()}</p>
</div>
);
}
}
SampleA.propTypes = propTypes;
SampleA.defaultProps = defaultProps;
export default SampleA;
ComponentB
import React, { Component } from 'react';
import PropTypes from 'prop-types';
const propTypes = {};
const defaultProps = {};
class SampleB extends Component {
constructor(props) {
super(props);
}
renderLastItem() {
if(!this.props.something) {
return null;
}
return this.props.something[this.props.something.length - 1];
}
render() {
return (
<div>
<ul>
<li>Something</li>
<li>Something else</li>
<li>{this.renderLastItem()}</li>
</ul>
</div>
);
}
}
SampleB.propTypes = propTypes;
SampleB.defaultProps = defaultProps;
export default SampleB;
You absolutely can pass props to a Higher-Order Component! A HOC is simply a function that takes a Component as an argument and returns another Component as a result. So you could create a Higher-Order withLastOfSomething Component just like this:
function withLastOfSomething(Component) {
return function({something, ...otherProps}) {
const item = something ? something[something.length - 1] : null;
return <Component item={item} {...otherProps} />;
}
}
Or with ES6 arrow functions, even more compactly like this:
const withLastOfSomething = (Component) => ({something, ...otherProps}) => {
const item = something ? something[something.length - 1] : null;
return <Component item={item} {...otherProps} />;
}
And then use it like this:
const SampleBWithLastOfSomething = withLastOfSomething(SampleB);
return (<SampleBWithLastOfSomething something={...} />);
You can separate the function that takes the passed props and executes the logic,
export default renderLastItem = (passedProps) => {
if(!passedProps) {
return null;
}
return passedProps [passedProps.length - 1]
}
then import it wherever you need, like this:
import renderLastItem from './somewhere'
export default class SampleA extends Component {
render() {
return (
<div>
<h1>Something</h1>
<p>{renderLastItem(this.props.something)}</p>
</div>
)
}
}