Iterating over children in stateless components react/react-native - reactjs

Question

I was working on a react-native application and I created a common component for display list items.
<View style={styles.container}>
<ItemsWithSeparator style={styles.itemsContainer}>
<AppRow />
<AppRow />
</ItemsWithSeparator>
</View>
Now, my ItemListSeparator is just iterates over the children and renders the list, so I thought I would make this a stateless component.
const ItemsWithSeparator = function ({children,style}) {
const childrenList = [];
const length = React.Children.count(children);
React.Children.forEach(
children,
(child,ii) => {
childrenList.push(child);
if (ii !== length -1) {
childrenList.push(
<View
key={`separator-${ii}`}
style={[styles.separator]}
/>
);
}
}
);
return (
<View style={style}>
{children}
</View>
);
};
But this throws an error saying 'React' not found.
However, it works fine with class based components. Following is the code which is working fine.
class ItemsWithSeparator extends React.Component {
render () {
const {children,style} = this.props;
const childrenList = [];
const length = React.Children.count(children);
React.Children.forEach(
children,
(child,ii) => {
childrenList.push(child);
if (ii !== length -1) {
childrenList.push(
<View
key={`separator-${ii}`}
style={[styles.separator]}
/>
);
}
}
);
return (
<View style={style}>
{children}
</View>
);
}
}
Can anyone help me understanding this? TIA!!
Update:
I was just trying few something and apparently got his to work:-
const ItemsWithSeparator = function ({children,style,...props}) {
const childrenList = [];
const length = React.Children.count(children);
React.Children.forEach(
children,
(child,ii) => {
childrenList.push(child);
if (ii !== length -1) {
childrenList.push(
<View
key={`separator-${ii}`}
style={[styles.separator]}
{...props}
/>
);
}
}
);
return (
<View style={style}>
{children}
</View>
);
};
But I am still a bit confused on how is this working. If someone could explain I would really be great.

Answer 1

Here is refactored version so you don't have to do this weird React.Children stuff :D Notice that you can return array when mapping children. There you can make if statements if needed.
const ItemsWithSeparator = ({children, style, ...props}) => {
const finalFields = children.map((child, index) => {
return [
child,
index !== children.length - 1 && (
<View key={index} {...props} style={styles.separator} />
)
];
});
return (
<View style={style}>
{finalFields}
</View>
);
};