Angular route guards are interfaces provided by angular which when implemented allow us to control the accessibility of a route based on condition provided in class implementation of that interface.
What is a guard in angular?
Guards are implemented as services that need to be provided so we typically create them as @Injectable classes. Guards return either true if the user can access a route or false if they can’t. … Angular will keep the user waiting until the guard returns true or false . Let’s create a simple CanActivate guard.
What are the types of guards in angular?
Different types of guards,
- CanActivate guard (e.g. it checks route access).
- CanActivateChild guard (checks child route access).
- CanDeactivate guard (prompt for unsaved changes).
- Resolve guard (pre-fetching route data).
- CanLoad guard (check before loading feature module assets).
What is Route guard?
Angular router’s navigation guards allow you to grant or remove access to certain parts of navigation. Here are the below types of route guards available: CanActivate : It is an interface a class can implement to decide if a route can be activated or not. If all guards return true, then navigation will continue.
What are guards and resolvers in angular?
The Angular Resolve Guard or Angular Resolvers allow us to load certain data before we navigate to a Route.
What is pipe in Angular?
Pipes are simple functions to use in template expressions to accept an input value and return a transformed value. Pipes are useful because you can use them throughout your application, while only declaring each pipe once.
What is CanDeactivate in Angular?
CanDeactivate is a TypeScript interface that needs to be implemented by a component to create a route guard. This guard will be used by the router to decide if the route can be deactivated. It can be implemented in any Angular component using the canDeactivate method of the interface.
What is Hashlocationstrategy in Angular?
A LocationStrategy used to configure the Location service to represent its state in the hash fragment of the browser’s URL.
What is an AuthGuard?
AuthGuard is a class which implements the interface CanActivate , to decide whether the user has access/permission to view specific page / route / path in the application or not. This will be useful when we need authentication/authorization based control over the application.
What is ActivatedRouteSnapshot in Angular?
Contains the information about a route associated with a component loaded in an outlet at a particular moment in time. ActivatedRouteSnapshot can also be used to traverse the router state tree.
Can you activate Auth guard?
What is CanActivate Guard. The Angular CanActivate guard decides, if a route can be activated ( or component gets rendered). We use this guard, when we want to check on some condition, before activating the component or showing it to the user. This allows us to cancel the navigation.
What is the purpose of Route guard?
Angular’s route guards are interfaces which can tell the router whether or not it should allow navigation to a requested route. They make this decision by looking for a true or false return value from a class which implements the given guard interface.
What is async pipe in Angular?
The async pipe subscribes to an Observable or Promise and returns the latest value it has emitted. When a new value is emitted, the async pipe marks the component to be checked for changes. When the component gets destroyed, the async pipe unsubscribes automatically to avoid potential memory leaks.
What does resolver do in Angular?
A Resolver is a class that implements the Resolve interface of Angular Router. In fact, Resolver is a service that has to be [provided] in the root module. Basically, a Resolver acts like middleware, which can be executed before a component is loaded. You may also like: Angular Resolvers.