Your Angular application includes a form that users utilize to submit sensitive data. How can you ensure that the form data is only submitted once, even if the user accidentally clicks the submit button multiple times?
- Implement a server-side mechanism that tracks and validates submitted data
- Use a client-side timer to disable the submit button for a fixed duration
- Use client-side JavaScript to check for duplicate submissions
- Utilize Angular guards to prevent multiple form submissions
To ensure that sensitive form data is submitted only once, you should utilize Angular guards to prevent multiple submissions. Angular guards allow you to control navigation and actions within your application.
Imagine you're building an Angular application that involves creating a directive to apply dynamic styling to elements. How can you pass values to your custom directive to make it reusable across different elements?
- Pass values through the DOM using attributes
- Use a service to share data between elements
- Use global variables to store values
- Use the @Input decorator to pass values as input properties
To make a directive reusable across different elements, you should use the @Input decorator to pass values as input properties.
What is the main difference between the combineLatest and withLatestFrom operators in RxJS?
- combineLatest emits only when all sources emit sequentially
- combineLatest emits only when all sources emit simultaneously
- withLatestFrom emits only when all sources emit simultaneously
- withLatestFrom emits when the source emits and the other observable emits, but not necessarily simultaneously
The main difference between combineLatest and withLatestFrom is that combineLatest emits when all sources emit simultaneously, while withLatestFrom emits when the source emits and the other observable emits, but not necessarily simultaneously.
Which built-in validator can be used to ensure a form control's value is required in Angular?
- isRequired
- mandatory
- required
- validateRequired
The **required** validator is used to ensure that a form control's value is required in Angular. It helps validate whether the control has a value.
To detach a component from Angular's change detection system, you would call the _____ method on the component's change detector.
- detach
- ngOnChanges
- ngOnInit
- onDestroy
To detach a component from Angular's change detection system, you would call the detach method on the component's change detector. This can be useful in certain optimization scenarios.
To mock a service's method and provide a custom return value during testing, you can use a Jasmine _____.
- Assertion
- MockService
- SpyOn
- TestBed
You should fill in the blank with SpyOn. Jasmine's SpyOn function allows you to mock methods and functions for testing, including services' methods.
You're developing a form-heavy application and notice that there's a noticeable lag when typing into input fields. Which technique can you use to improve the performance related to data binding?
- One-way data binding
- Two-way data binding
- OnPush change detection strategy
- Component state management
In a form-heavy application, using the OnPush change detection strategy (option c) can significantly improve performance by reducing unnecessary change detection cycles. This strategy ensures that updates are only triggered when input properties change.
Imagine you're building a multi-step form and you want to navigate between steps while preserving the data entered in the form. How would you leverage Navigation Extras to achieve this?
- Pass the form data in URL query parameters using NavigationExtras
- Store form data in a shared service and access it as you navigate between steps
- Use Angular Forms Module to keep track of form data and share it between steps
- Utilize localStorage to store and retrieve form data
To navigate between steps of a multi-step form while preserving the entered data, you can leverage Navigation Extras to pass the form data in URL query parameters using the NavigationExtras provided by Angular.
How can you pass data to a route while navigating to it?
- Using route guards
- Using route parameters
- Using route resolvers
- Using the query string
You can pass data to a route while navigating to it by using route parameters. Route parameters allow you to send data directly in the URL when navigating to a specific route.
To guard a route against unauthorized access, you can implement a custom class that implements the _____ interface.
- AuthenticationGuard
- CanActivate
- CanActivateChild
- RouteGuard
To guard a route against unauthorized access, you can implement a custom class that implements the CanActivate interface.