Week 7 - Todo-Add App
Tags: react, hook, usestate, events
Published: 2022-07-01 05:06:50

---
title: Week 7 - Todo-Add App
published: true
description: creating small UI component to build large scale projects
tags: reactjs, hook, useState, events
cover_image: https://i.imgur.com/j45j28v.jpg
key: 1
series: React Curve
---

## Welcome to Week 7 of React Curve

Hello developer!, glad to see you again.

This is a react-curve, open source project where I can share and start creating small UI components in the way I understood the concepts to build large scale projects .

----------------

## Todo-Add App

![Todo-Add app](https://i.imgur.com/8eXcruN.gif)
This week we created a todo-add app. An app that allows user to add any tasks in a form in react.

To create a Todo-Add component; We have to :

* Create three components, the parent TodoAddV1, ItemForm and PrintItems child components.
* In the parent TodoAddV1 component, Create a state that store the lists and function to update what’s on the screen in response to submit button.
* In handleAddItem method, when we want to update an array stored in state, we need to make a copy of an existing one, and then set state to use the new array.
* Send handleAddItem method to ItemForm component and send lists to PrintItems component as props.
* In the child ItemForm component, Create a state that store the item and function that handle updates in response to change input and submit button.
* We handleInputChange and submit when user interact with the form.
* Finally, In the child PrintItems component, We just map to render the list items and print the name of the item.

## Code

### TodoAddV1 Component
```react

import React, {useState} from 'react';

import ItemForm from './ItemForm';
import PrintItems from './PrintItems';

const TodoAddV1 = () => {
    const [lists, setLists] = useState([])

    const handleAddItem = (item) => {
      item.id = lists.length + 1
      setLists([...lists, item])
    }

    return (
         <div>
           <h2>Add to Todo</h2>
 
           <ItemForm addItem={handleAddItem} />
           <PrintItems lists={lists} />
         </div>
    );
}

export default TodoAddV1;
```

### ItemForm Component

```react
import React, {useState} from 'react'; 

const ItemForm = (props) => {
  const initialFormState = { id: null, name: '' }
  const [item, setItem] = useState(initialFormState)

  const handleInputChange = (ev) => {
    const { name, value } = ev.target
  
    setItem({ ...item, [name]: value })
  }

  const handleSubmit = (ev) => {
    ev.preventDefault()
    if (!item.name) return
    props.addItem(item)
    setItem(initialFormState)
  }

  return (
    <>
      <form onSubmit={handleSubmit}>
        <label>Enter Item</label> <br />
        <input
          type="text"
          name="name"
          value={item.name}
          onChange={handleInputChange}
        />
        <br />
        <button>Add new item</button>
      </form>
    </>
  );
}

export default ItemForm;
```

### PrintItems Component

```react
import React from 'react';

const PrintItems = (props) => {
  return (
    <div>
      {props.lists.length > 0 ? (
        props.lists.map((item) => (
          <ul key={item.id}>
            <li>{item.name}</li>
          </ul>
        ))
      ) : (
        <div>
          No items
        </div>
      )}
    </div>
  );
}

export default PrintItems;
```

### Conclusion
Thank you for reading and any contribution is more than welcome in the threads below!

[Live Preview](https://this-react-curve.vercel.app/todo-add-v1)