In this article, I will be using rest API ( JSON placeholder ) with fake data instead of static js object. Real apps work with APIs.
If you want to see the class based approach read this article.
Let's begin
Hooks are just like functions. We call it the same as we call functions
useState()
useState accept an argument that is initial value for the state and return two things current value and method for update the state property.
Declaing State
const [employees, setEmployees] = useState([])
its same as
const array = useState([])
const employees = array[0]
const setEmployees = array[1]
We wrote it in one line using array destructuring.
We define employees as an empty array, as soon we will hit the API, the state will change and put all the API data into employees array.
Get Data Function
const getData = async () => {
let url = 'https://jsonplaceholder.typicode.com/users'
const response = await axios.get(url)
console.log('response', response)
setEmployees(response.data)
}
We are using axios for http requests.
We need to download axios through terminal.
npm i axios
We made the getData function async because it takes some time to fetch data from API. So we said wait until the data is loaded then save it in response variable.
In previous article we called api in componentDidMount but useEffect hook has replaced componentDidMount, useEffect is easier to read, and write.
useEffect(() => {
getData()
}, []) // don't forget this empty bracket it indicates the function will only run once when the component will load initially
For Table Header
const renderHeader = () => {
let headerElement = ['id', 'name', 'email', 'phone', 'operation']
return headerElement.map((key, index) => {
return <th key={index}>{key.toUpperCase()}</th>
})
}
First of all, we will decide how many columns we need for our table and then define these values in an array. In our case we need 5 columns, now we will map over these values and output as th
Operation is for Edit and Delete functionality.
For Table Body
const renderBody = () => {
return employees && employees.map(({ id, name, email, phone }) => {
return (
<tr key={id}>
<td>{id}</td>
<td>{name}</td>
<td>{email}</td>
<td>{phone}</td>
<td className='opration'>
<button onClick={() => removeData(id)}>Delete</button>
</td>
</tr>
)
})
}
Here you may have noticed the logic employees && employees.map, we are saying employees.map will only run if we have employee. Because it took some seconds to load the data from server, and if we will not write this logic our code will break, because employees array will be empty initially and map will not run on empty array, it won't have id, name and rest of the field, so it will through error.
Don't get confused with { id, name, email, phone } we just destructured the object.
We are also passing id as a parameter to removeData method.
Main return function
We just called both of our methods in our main return function.
return (
<div>
<h1 id='title'>React Table</h1>
<table id='employee'>
<thead>
<tr>{renderHeader()}</tr>
</thead>
<tbody>
{renderBody()}
</tbody>
</table>
</div>
)
}
Delete functionality
We can send four kinds of requests via axios
- get
- post
- delete
- put
For delete, we will send a delete request. As the name says we use this method to delete a record on the backend.
delete takes the url as a parameter with the specific id of the record we want to delete. We will send id as a parameter.
Some of the time JSON placeholder API don't accept delete request and you won't feel the change on frontend this is just for demo purpose.
const removeData = (id) => {
let url = `https://jsonplaceholder.typicode.com/users/${id}`
axios.delete(url).then(res => {
const del = employees.filter(employee => id !== employee.id)
setEmployees(del)
console.log('res', res)
})
}
In our case, we can see data will be deleted on frontend but not on the backend. Because we can not manipulate JSON placeholder API. But if we have our own API that has delete feature too. It would just work fine.
To show the user, the data has been deleted we filtered the deleted object from frontend using higher-order filter method.
Refactoring Code
Organizing and refactoring code is essential. You may have noticed we have used URL in two different places, what if in future we need to change the URL? are we going to change from both places? no, we should have one common place where we define URL.
- In real projects, we have a config file for that but for this one component base app, I will define
URLon top of the file. - We also have to remove the consoles it was only for testing purposes.
- We don't want initial
div. For that, we will just use an empty bracket.
useApi custom hook
we can clean up our component and make code modular, just switching all of our business logic to a custom hook, useApi hook can be used in multiple places in our app.
import { useState, useEffect } from 'react'
import axios from 'axios'
export function useAPi(url) {
const [data, setData] = useState([])
useEffect(() => {
getData()
}, [])
const getData = async () => {
const response = await axios.get(url)
setData(response.data)
}
const removeData = (id) => {
axios.delete(`${url}/${id}`).then(() => {
const del = data.filter((item) => id !== item.id)
setData(del)
})
}
return { data, removeData }
}
This is straightforward
- We will pass API
urlas params. - Returns the
data(this is our employee data) andremoveDatafunction.
Complete Code
import React from 'react'
import { useAPi } from '../../hooks/useApi'
const URL = 'https://jsonplaceholder.typicode.com/users'
const Table = () => {
const { data, removeData } = useAPi(URL)
const renderHeader = () => {
let headerElement = ['id', 'name', 'email', 'phone', 'operation']
return headerElement.map((key, index) => {
return <th key={index}>{key.toUpperCase()}</th>
})
}
const renderBody = () => {
return (
data &&
data.map(({ id, name, email, phone }) => {
return (
<tr key={id}>
<td>{id}</td>
<td>{name}</td>
<td>{email}</td>
<td>{phone}</td>
<td className="operation">
<button className="button" onClick={() => removeData(id)}>
Delete
</button>
</td>
</tr>
)
})
)
}
return (
<>
<h1 id="title">React Table</h1>
<table id="employee">
<thead>
<tr>{renderHeader()}</tr>
</thead>
<tbody>{renderBody()}</tbody>
</table>
</>
)
}
export default Table
Isn't it much cleaner? our business logic is completely separated now.
Styling
@import url("https://fonts.googleapis.com/css2?family=Quicksand:wght@500&display=swap");
body {
font-family: "Quicksand", sans-serif;
display: flex;
justify-content: center;
padding: 0;
color: #4d4d4d;
}
#title {
text-align: center;
}
#employee {
border-collapse: collapse;
border: 3px solid #ddd;
}
#employee td,
#employee th {
border: 1px solid #ddd;
padding: 12px;
}
#employee tr:hover {
background-color: #ddd;
}
#employee th {
padding: 10px;
text-align: center;
background-color: #4caf50;
color: white;
}
.operation {
text-align: center;
}
.button {
border: none;
outline: none;
font-size: 11px;
font-family: "Quicksand", sans-serif;
color: #f44336;
padding: 3px 10px;
border-radius: 8px;
cursor: pointer;
border: 1px solid #f44336;
background-color: transparent;
}
.button:active {
border: 1px solid blue;
}
Codepen Link
This is the codepen demo of the project
Nice post!