You want to create a component that updates its displayed data whenever the route parameter postId changes without recreating the component. Which approach correctly handles this using ActivatedRoute?
hard🚀 Application Q15 of 15
Angular - Routing
You want to create a component that updates its displayed data whenever the route parameter postId changes without recreating the component. Which approach correctly handles this using ActivatedRoute?
ARead <code>postId</code> once in the constructor and store it
BReload the entire component manually on route change
CUse <code>snapshot.paramMap.get('postId')</code> only in <code>ngOnInit</code>
DSubscribe to <code>paramMap</code> in <code>ngOnInit</code> and update data inside the subscription callback
Step-by-Step Solution
Solution:
Step 1: Understand component reuse on route param change
Angular reuses the component instance when only route parameters change, so ngOnInit runs once.
Step 2: Use paramMap subscription to detect param changes
Subscribing to paramMap lets you react to parameter changes dynamically without recreating the component.
Step 3: Why snapshot is insufficient
snapshot.paramMap reads parameters only once and won't update if params change while component is active.
Final Answer:
Subscribe to paramMap in ngOnInit and update data inside the subscription callback -> Option D
Quick Check:
Subscribe paramMap for dynamic param changes [OK]
Quick Trick:Subscribe to paramMap to handle param changes live [OK]
Common Mistakes:
MISTAKES
Using snapshot only and missing param updates
Reading param once in constructor
Manually reloading component instead of subscribing
Master "Routing" in Angular
9 interactive learning modes - each teaches the same concept differently
