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Great question! To efficiently sync a user's interests (stored as a JS array) with your Drizzle/Postgres backend when they update their interests via a mutation, you should:
1. Data Model
Assume:
personstable (id, name, ...)intereststable (id, name)person_intereststable (person_id, interest_id) — many-to-many relationship
2. Frontend Flow
- User sends the full, updated array of interests (e.g.
["music", "coding", "cooking"]) when they save.
3. Backend Mutation Steps
a. Upsert interests
- For each interest in the array, ensure it exists in the
intereststable.- Use Drizzle’s
insertwithonConflictDoNothing(or similar) to avoid duplicates.
- Use Drizzle’s
b. Fetch Interest IDs
- Retrieve all interest IDs for the submitted names.
c. Sync Person's Interests
- Fetch the current interests for the person from
person_interests. - Compute:
- To Add: Interests in the new array but not in DB.
- To Remove: Interests in DB but not in the new array.
- Use Drizzle to insert new links and delete old ones.
Sample Drizzle Code
// 1. Upsert interests
await db.insert(interests).values(
newInterests.map(name => ({ name }))
).onConflictDoNothing(); // prevents duplicate interest names
// 2. Get interest IDs
const interestRecords = await db
.select({ id: interests.id, name: interests.name })
.from(interests)
.where(in(interests.name, newInterests));
const interestIdMap = Object.fromEntries(
interestRecords.map(rec => [rec.name, rec.id])
);
// 3. Get current user's interests
const currentLinks = await db
.select({ interest_id: person_interests.interest_id })
.from(person_interests)
.where(eq(person_interests.person_id, personId));
const currentInterestIds = new Set(currentLinks.map(l => l.interest_id));
const newInterestIds = new Set(Object.values(interestIdMap));
// 4. Compute changes
const toAdd = [...newInterestIds].filter(id => !currentInterestIds.has(id));
const toRemove = [...currentInterestIds].filter(id => !newInterestIds.has(id));
// 5. Add new links
if (toAdd.length > 0) {
await db.insert(person_interests).values(
toAdd.map(interest_id => ({
person_id: personId,
interest_id,
}))
);
}
// 6. Remove old links
if (toRemove.length > 0) {
await db.delete(person_interests)
.where(
and(
eq(person_interests.person_id, personId),
in(person_interests.interest_id, toRemove)
)
);
}Why this approach?
- Efficient: Only adds/removes what's changed.
- Prevents duplicates.
- Handles many-to-many properly.
- Works with Drizzle and Postgres.
Tips
- Wrap in a transaction for atomicity.
- Validate input on the backend.
- You do not update interests themselves, just the linking table.
If your interests are not a separate table (i.e., you store them as a JSON array), the approach is simpler (just update the array), but you'll lose normalization, searchability, and de-duplication features.
Let me know if you want the code adapted for a different schema or want transaction handling!
To type a generic ReactNode that guarantees a className prop, you’ll want to constrain the type to a React element that accepts props — particularly one that includes className. A plain ReactNode is too flexible (it can be a string, fragment, boolean, etc.), so you’ll need a more refined approach.
Here’s a pattern that works well:
import React, { ReactElement, ComponentType } from 'react';
type WithClassNameProps = {
className?: string;
};
type Props<T extends ComponentType<WithClassNameProps>> = {
Component: T;
};
// Example usage
const Wrapper = <T extends ComponentType<WithClassNameProps>>({
Component,
}: Props<T>) => {
return <Component className="my-class" />;
};🔍 What’s happening here:
ComponentType<P>is a generic for a React component that accepts props of typeP.- We're restricting it with
WithClassNamePropsso we know for sure it acceptsclassName. - This ensures your passed-in
Component(like adiv,button, or custom component) will support theclassNameprop at type level.
If you’re passing an actual element (like <div />) rather than a component reference, you’d use ReactElement<WithClassNameProps> instead.
Would you like an example with JSX-style children too? Or maybe you want to extend the prop checks even further?
React.cloneElement is a powerful—but often misunderstood—tool in React’s arsenal. It lets you create a new React element based on an existing one, while overriding or adding props and children. Here's why and when you'd use it:
🧩 Why Use React.cloneElement()
- Inject props into children: Useful when a parent component needs to modify or extend its children without changing their original implementation.
- Enhance reusability: You can build flexible, reusable UI components by dynamically customizing child elements.
- Avoid prop drilling: Instead of passing props through multiple layers, cloneElement lets you inject them directly.
📦 Common Use Cases
-
Customizing child components:
const cloned = React.cloneElement(<Button />, { color: 'red' });
This creates a new
<Button />with thecolorprop set to'red'. -
Dynamic rendering in lists:
React.Children.map(children, (child, index) => React.cloneElement(child, { isActive: index === selectedIndex }) );
This is handy for components like tabs or selectable lists.
-
Wrapping components with additional behavior:
For example, adding event handlers or styling to children passed into a container.
⚠️ Caveats
- Can make code harder to trace: Since props are injected dynamically, it’s not always obvious where they come from.
- Not ideal for static typing: TypeScript may struggle with inferred props when using cloneElement.
- Better alternatives often exist: Consider using render props, context, or custom hooks for clearer data flow.
Would you like to see a real-world example or explore alternatives like render props or context?
``
const [selection, setSelection] = useState({ state: {}, items: [] });
const table = useReactTable({
data,
columns,
getRowId: row => row.id,
state: { rowSelection: selection.state },
onRowSelectionChange: updater => {
const newState = updater(selection.state);
const selectedItems = data.filter(item => newState[item.id]);
setSelection({ state: newState, items: selectedItems });
},
});
type OnlyArrays<T> = {
[K in keyof T]: T[K] extends any[] ? K : never
}[keyof T]
type ArrayItemType<T> = T extends (infer U)[] ? U : never;
function access<
T extends object,
K extends OnlyArrays<T>,
A extends (a: ArrayItemType<T[K]>) => boolean
>
(first: T, key: K, func: A): {
added: Array<ArrayItemType<T[K]>>
} {
const added = (first[key] as Array<ArrayItemType<T[K]>>).filter(func)
return {
added,
}
}
access(obj, "addresses", (a) => true);improvement
function access<
T extends Record<K, any[]>,
K extends keyof T,
A extends (a: ArrayItemType<T[K]>) => boolean
>(
first: T,
key: K,
func: A
): {
added: ArrayItemType<T[K]>[]
} {
const added = first[key].filter(func);
return { added };
}
use ref for performance gains:
https://www.youtube.com/watch?v=TgpTG5XYoz4