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Creating a message component for displaying error in ReactJS

 4 years ago
source link: https://dev.to/kitlung/creating-a-message-component-for-displaying-error-in-reactjs-5cm4
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Creating a message component for displaying error in ReactJS

Apr 10

・2 min read

Hi,
Today I would like to share my way of displaying error or custom messages in React.
The idea is to use context and custom hook so we are able to access the component on all pages.

Custom Message Context Provider

Let's create a context provider first.

// CustomMessageProvider.tsx

import { createContext, useState } from 'react';

/*
* show : whether show or hide the message block
* type : what theme is the message block
* msg : message displaying on the message block
* 
* You can add more field if you want
*/
interface Msg {
  show: boolean;
  type: 'error' | 'info' | 'success' | 'warning';
  msg: string;
}

const defaultMsg = {
    show: false,
    type: 'success',
    msg: ''
} as Msg

export const CustomMessageContext = createContext({
    msg: initMsg as Msg,
    setMsg: (_: Msg) => {}
})

const CustomMessageProvider = ({children}) => {
    const [msgState, setMsgState] = useState(initMsg)

// CustomMessageContext contains an object 
// and also a method for setState

    const contextValue = {
        msg: msgState,
        setMsg: (val: Msg) => setMsgState(val)
    }
    return (
        <CustomMessageContext.Provider value={contextValue}>
            {children}
        </CustomMessageContext.Provider>
    );
}
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Then we can add the provider to App.tsx so that we can access the context on all pages.

// App.tsx
const App = () => {
    <CustomMessageProvider>
    ...
    </CustomMessageProvider>
}
export default App
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Great!

Custom hook

What we are going to do now is to add a custom hook so we don't have to call useContext in all pages

// customMessageHook.tsx
const useMsg = () => {
    const { msg, setMsg } = useContext(CustomMessageContext);
    return { msg, setMsg };
}
export default useMsg;
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Integration

We can now call useMsg on all pages.
Let say you want to display an error if the fetch API failed on a page.

const { setMsg } = useMsg();

...

const fetchApi = async () => {
    try {
        ...
    } catch (err) {
        setMsg({
            show: true, 
            type: 'error',
            msg: 'Oops, error'
        })
    }
}
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Ending

I know there are some more elegant ways to implement this, feel free to leave me a comment and share what you think.
Have a nice day.


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