minimize requests to backend from frontend on event page DOT-262 #696
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
The queries made to the backend from online.ntnu.no/events/{event} are expensive. To avoid that the backend crashes on big events, we want to be smart about how many requests we send from the frontend.
Measures
Double fetching bug
Prev behaviour: User goes to the event detail page. Event/attendance event data is fetched from backend. This is done in a useEffect with userLoggedIn as dep. This causes useEffect to be ran twice, as isLoggedIn goes from false on init to true.
Now: event data is fetched from the backend once independent of user being logged in or not. For the user, there is no difference as to before.
Caching backend response when fresh content is not needed