Good.
This is EXACTLY the kind of structure you should learn deeply because this is real-world React architecture.
Your file are separating responsibilities into layers:
API Core
↓
REST Client Function
↓
TanStack Query
↓
Output
This is actually a VERY good pattern.
Let’s break down WHY each exists.
1. API Core
const apiCore = new APICore();
This is usually a wrapper around:
fetch()
axios()
WHY create API Core?
Instead of writing this everywhere:
fetch("https://api.com/users", {
headers: {
Authorization: token
}
})
You centralize logic.
Real Purpose of API Core
Usually handles:
- base URL
- auth token
- headers
- interceptors
- error handling
- refresh token
- common request logic
Example
Without API Core:
fetch(...)
fetch(...)
fetch(...)
fetch(...)
Repeated everywhere.
BAD scalability.
With API Core
apiCore.get()
apiCore.post()
Clean and reusable.
Mental Model
API Core = HTTP Engine
It is your application's communication layer.
Why NOT call fetch directly everywhere?
Because later:
- token changes
- auth changes
- API version changes
- error structure changes
You would update 100 files.
With API Core:
update ONE place.
Real Senior Thinking
This is called:
Abstraction
Hide complexity behind simple interface.
2. REST Client Function
This part:
const readUbots = async (): Promise<UbotsResponse> => {
const response = await apiCore.get(`${UBOTS}/${id}`);
return response.data.body;
};
What This Layer Does
This function represents ONE backend operation.
Example:
read user
create user
delete user
update product
WHY separate this?
Because:
Query logic ≠ API logic
Very important separation.
This Function's Job
ONLY:
Talk to backend
Return data
Nothing else.
Why This Is Good
Now this function becomes reusable.
Example:
readUbots()
can be used in:
- TanStack Query
- button click
- server-side render
- testing
- websocket refresh
Why NOT put fetch directly inside useQuery?
BAD:
useQuery({
queryFn: async () => {
...
}
})
Works.
But scales badly.
Because:
- harder to reuse
- harder to test
- logic becomes coupled
Architecture Thinking
This layer is usually called:
Service Layer
API Layer
REST Client
Repository
depending on company.
3. TanStack Query
THIS is the most important modern React concept.
useQuery()
TanStack Query solves:
Server State Management
Big Important Distinction
There are TWO types of state:
UI State
Example:
modal open
sidebar collapsed
input text
tab selected
Usually use:
Server State
Example:
users from API
products from backend
notifications
messages
This is DIFFERENT.
Because:
- async
- cacheable
- stale
- shared
- refetchable
Before TanStack Query
People did:
useEffect(() => {
fetch(...)
}, [])
This became a nightmare at scale.
Problems
You had to manage:
- loading
- caching
- retry
- stale data
- deduplication
- refetching
- background sync
- errors
MANUALLY.
TanStack Query Solves All That
const { data, isLoading } = useQuery(...)
Very powerful abstraction.
Mental Model
TanStack Query = Smart Server-State Manager
queryKey
queryKey: ['ubots', id]
VERY important.
This is cache identity.
Why Query Key Exists
React Query caches data.
Example:
['users']
['users', 1]
['products']
Different cache buckets.
Why Include id
Because:
uBot 1 ≠ uBot 2
Each needs separate cache.
queryFn
queryFn: readUbots
This tells TanStack:
How to fetch data
enabled
enabled: !!id
VERY important pattern.
What !!id Means
Convert value to boolean.
Example:
!!undefined = false
!!"123" = true
Why Needed?
Without it:
React Query runs immediately.
Even if:
id = undefined
Then API becomes:
/ubots/undefined
BAD.
So enabled Prevents Invalid Requests
No ID → don't fetch
Has ID → fetch
refetchOnWindowFocus
refetchOnWindowFocus: false
By default:
TanStack refetches when user returns to tab.
Why?
Because data may be stale.
Why Disable It?
Sometimes:
- unnecessary API calls
- annoying refreshes
- performance concerns
Depends on UX.
4. Output Layer
return {
data,
isFetching,
isFetched,
isError,
};
This makes hook reusable.
IMPORTANT:
This file is a CUSTOM HOOK
useReadUbots
This is NOT just a function.
This is reusable React logic.
Why Custom Hooks Exist
Without them:
Every component repeats:
loading logic
query logic
error logic
data logic
Again and again.
Custom Hook Encapsulates Logic
Now component becomes:
const { data } = useReadUbots(id);
VERY clean.
Senior-Level Architecture Happening Here
Your code is separating:
Transport Layer → API Core
Backend Operation → REST Function
Server State → TanStack Query
UI Consumption → Output
This is GOOD architecture.
One More Important Thing
This:
export default function useReadUbots(id?: string)
means:
id is optional
because:
?
Why Optional?
Sometimes component mounts before router param exists.
Example:
const { id } = useParams();
Initially:
So hook handles safely.
Very Important React Understanding
React apps are:
asynchronous
Data often DOES NOT exist immediately.
This is why React developers constantly manage:
- loading
- empty state
- undefined
- fallback UI
What Beginners Usually Do Wrong
1. Put everything in component
BAD scalability.
2. Fetch directly in JSX
Very messy.
3. Mix UI and API logic
Creates tightly coupled code.
Your File is Actually Following Good Patterns
You should learn:
- WHY each layer exists
- what problem it solves
- how separation improves scaling
THAT is real React understanding.
Not memorizing syntax.
