Fundamentals
React Application Lifecycle
1. Mounting Phase
- constructor(props): Initializes state and binds methods.
- static getDerivedStateFromProps(nextProps, prevState): Updates state based on props.
- render(): Returns JSX to render.
- componentDidMount(): Invoked after the component mounts; ideal for API calls.
2. Updating Phase
- static getDerivedStateFromProps(nextProps, prevState): Updates state before rendering.
- shouldComponentUpdate(nextProps, nextState): Decides if re-rendering is necessary.
- render(): Renders the updated component.
- getSnapshotBeforeUpdate(prevProps, prevState): Captures information before updates.
- componentDidUpdate(prevProps, prevState, snapshot): Invoked after updates; useful for side effects.
3. Unmounting Phase
- componentWillUnmount(): Cleans up resources before the component is removed from the DOM.
QnA
What’s the difference b/w IServiceCollection vs IServiceProvider?
IServiceProvider
- Responsible for resolving services and creating instances of registered types
- Provides methods like
GetService(),GetRequiredService(), andGetServices()to retrieve service instances
- Can be injected into classes as a constructor parameter to allow resolving dependencies
- Should be used sparingly to avoid the Service Locator anti-pattern
- Useful in cases where you need to dynamically create scoped instances, like in multithreaded apps
IServiceCollection
- Used to register services and configure their lifetime (transient, scoped, singleton)
- Cannot be injected into class constructors directly
- Provides extension methods like
AddTransient(),AddScoped(),AddSingleton()to register services
- Ultimately used to build an
IServiceProviderinstance viaBuildServiceProvider()