useState hook losing map data on page refresh - reactjs

Question

I am using useState hook for my add product form.
When I refresh my page, data is not displaying for the field category (I am trying to display categories, so the user can select category from the list to create a product for that category). But! Data keeping in redux store:
enter image description here
It only shows when I go to another page using react router() and then go back.
This is my code:
export const AddProduct = () => {
const dispatch = useDispatch();
const userId = useSelector(state => state.auth.userId);
const categories = useSelector(state => state.categories.categories);
const [avatar, setAvatar] = React.useState('');
React.useEffect(() => {
dispatch(categoriesActions.fetchCategories());
}, [dispatch]);
const [orderForm, setOrderForm] = React.useState({
title: {
elementType: 'input',
label: 'Title',
elementConfig: {
type: 'text',
placeholder: 'Title'
},
value: '',
validation: {
required: true
},
valid: false,
touched: false
},
price: {
elementType: 'input',
label: 'Price',
elementConfig: {
type: 'text',
placeholder: 'Price'
},
value: '',
validation: {
required: true
},
valid: false,
touched: false
},
description: {
elementType: 'textarea',
label: 'Description',
elementConfig: {
type: 'text',
placeholder: 'Description'
},
value: '',
validation: {
required: true
},
valid: false,
touched: false
},
category: {
elementType: 'select',
label: 'Select category',
elementConfig:
categories.map(category => (
<option key={category._id} value={category.title}>
{category.title}
</option>))
,
value: '',
validation: {
required: true
},
valid: false,
touched: false
},
});
const [formIsValid, setFormIsValid] = React.useState(false);
const addProductData = event => {
event.preventDefault();
const formData = {};
for (let formElementIdentifier in orderForm) {
formData[formElementIdentifier] = orderForm[formElementIdentifier].value;
}
const product = {
userId: userId,
title: formData.title,
price: formData.price,
description: formData.description,
category: formData.category
}
dispatch(productsActions.addProduct(product));
}
const inputChangedHandler = (event, inputIdentifier) => {
const updatedFormElement = updateObject(orderForm[inputIdentifier], {
value: event.target.value,
valid: checkValidity(
event.target.value,
orderForm[inputIdentifier].validation
),
touched: true
});
const updatedOrderForm = updateObject(orderForm, {
[inputIdentifier]: updatedFormElement
});
let formIsValid = true;
for (let inputIdentifier in updatedOrderForm) {
formIsValid = updatedOrderForm[inputIdentifier].valid && formIsValid;
}
setOrderForm(updatedOrderForm);
setFormIsValid(formIsValid);
};
const formElementsArray = [];
for (let key in orderForm) {
formElementsArray.push({
id: key,
config: orderForm[key]
});
}
let form = (
<form onSubmit={addProductData}>
{formElementsArray.map(formElement => (
<Input
key={formElement.id}
elementType={formElement.config.elementType}
elementConfig={formElement.config.elementConfig}
value={formElement.config.value}
label={formElement.config.label}
hint={formElement.config.hint}
invalid={!formElement.config.valid}
shouldValidate={formElement.config.validation}
touched={formElement.config.touched}
changed={event => inputChangedHandler(event, formElement.id)}
/>
))}
<Button btnType="Success" disabled={!formIsValid}>ORDER</Button>
</form>
)
return (
<div class="wrapper">
<Header />
<article class="main">
<div class="row">
<div class="item--1-4 image-block">
<div class="product-image-group">
<img class="product-image-big" src={`/${avatar}`} />
<hr class="border-divider" />
<input type="file" onChange={e => setAvatar(e.target.files[0].name)} name="imageUrl" id="imageUrl" />
</div>
</div>
<div class="item--3-4">
<div class="item-title">
<h3>Add product</h3>
<hr class="border-divider" />
</div>
{form}
</div>
</div>
</article>
<LeftMenu />
</div>
)
}
This is line in my code related to that select field:
elementConfig:
categories.map(category => (
<option key={category._id} value={category.title}>
{category.title}
</option>))

Answer 1

That's because the first time that component loads, there is nothing in the categories and when the categories are set, you're not setting the orderForm data again. this is called stale props you need to do this:
useEffect(() => {
setOrderForm((oldValue) => ({
...oldValue,
category: {
...oldValue.category,
elementConfig: categories.map((category) => (
<option key={category._id} value={category.title}>
{category.title}
</option>
)),
},
}));
}, [categories])
This way every time categories data is changed you changing the orderForm state accordingly