The useCodingTask
hook is a custom React hook that provides functionality for fetching and managing coding task data in the advanced to-do application. It enriches the basic task data with user information and metadata to create a comprehensive data structure that components can easily consume.
The useCodingTask
hook leverages the Ontology SDK (OSDK) to interact with backend services in a type-safe manner, using the powerful $as
operator to pivot between different object type implementations. It also demonstrates effective use of React's state management and memoization patterns to optimize performance.
View the useCodingTask
reference code.
useCallback
for memoizing functions to prevent unnecessary re-renders$as
operator for type-safe pivoting between object typesuseCodingTask
structureCopied!1 2 3 4 5
interface CodingTaskEnriched { osdkCodingTask: osdkCodingTask.OsdkInstance; createdBy: User; assignedTo: User; }
This interface combines the SDK's coding task instance with user objects for the task creator and assignee, creating a unified data structure that simplifies component implementation.
The useCodingTask
hook uses SWR data fetching capabilities with a custom fetcher function that does the following:
$as
operator to pivot to the coding task interface implementationCodingTaskEnriched
object with the retrieved dataCopied!1 2 3 4 5 6 7 8 9
const fetcher = useCallback(async () => { const codingTask = task.osdkTask.$as(osdkCodingTask); const codingTaskEnriched = { osdkCodingTask: codingTask, createdBy: task.createdBy, assignedTo: task.assignedTo, }; return codingTaskEnriched; }, [task]);
The useCodingTask
hook configures SWR to minimize unnecessary network requests:
Copied!1 2 3 4
{ revalidateOnFocus: false, revalidateOnReconnect: false, }
The useCodingTask
hook retrieves object type metadata to enable dynamic UI features:
Copied!1 2 3 4 5 6 7 8
const getObjectTypeMetadata = useCallback(async () => { const objectTypeMetadata = await client.fetchMetadata(osdkCodingTask); setMetadata(objectTypeMetadata); }, [client]); useEffect(() => { getObjectTypeMetadata(); }, [getObjectTypeMetadata]);
This metadata provides information about the coding task object type (such as display names and field configurations) that components can use for rendering.
The useCodingTask
hook returns an object with the following structure:
Copied!1 2 3 4 5 6 7
{ codingTask: CodingTaskEnriched | undefined; // The enriched coding task (undefined if not loaded) isLoading: boolean; // True during initial data loading isValidating: boolean; // True during background revalidation isError: any; // Error object if the request failed metadata: ObjectMetadata | undefined; // Metadata about the coding task object type }
This comprehensive return value gives components all the information they need to handle various states and render the appropriate UI.
The useCodingTask
hook uses the $as
operator to pivot between related object types:
Copied!1
const codingTask: osdkCodingTask.OsdkInstance = task.osdkTask.$as(osdkCodingTask);
This pattern leverages TypeScript's type system to safely transition between related object types:
task.osdkTask
) has a polymorphic structure$as
operator performs a runtime check to verify compatibilityThis approach is essential for polymorphic data models where a base object can have specialized subtypes.
The hook employs React's useCallback
to optimize performance:
Copied!1 2 3 4 5 6 7
const fetcher = useCallback(async () => { // Fetcher logic }, [task]); const getObjectTypeMetadata = useCallback(async () => { // Metadata fetching logic }, [client]);
This pattern dose the following:
The following external packages can be used with the useCodingTask
hook.
Purpose: Ontology SDK client for interacting with a backend data service Benefits:
useOsdkClient
for accessing the client instancePurpose: Application-specific SDK with predefined data types. Benefits:
osdkCodingTask
).Purpose: Data fetching, caching, and state management Benefits:
Copied!1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38
function CodingTaskDetails({ task }) { const { codingTask, isLoading, isError, metadata } = useCodingTask(task); if (isLoading) return <div>Loading coding task details...</div>; if (isError) return <div>Error loading coding task: {isError.message}</div>; if (!codingTask) return <div>No coding task found</div>; return ( <div className="coding-task-details"> <h2>{codingTask.osdkCodingTask.title}</h2> <div className="metadata-section"> <h3>Task Metadata</h3> <div>Object Type: {metadata?.displayName || "Coding Task"}</div> </div> <div className="code-section"> <h3>Code Requirements</h3> <div className="language-badge">{codingTask.osdkCodingTask.language}</div> <pre> <code>{codingTask.osdkCodingTask.codeSnippet}</code> </pre> </div> <div className="people-section"> <h3>People</h3> <div className="assigned-to"> <span>Assigned to: </span> <span>{codingTask.assignedTo?.displayName || "Unassigned"}</span> </div> <div className="created-by"> <span>Created by: </span> <span>{codingTask.createdBy?.displayName || "Unknown"}</span> </div> </div> </div> ); }
Consider the following scenarios and limitations before using the useCodingTask
hook:
undefined
for createdBy
or assignedTo
. Components should handle this gracefully.$as
operation may fail at runtime. The hook does not currently handle this error case explicitly.useCodingTask
hook depends entirely on the parent task object. If that object is malformed or missing essential data, the hook may not function as expected.