Custom Decorators
Server Enviroment
Client Enviroment
Overview
Decorators are a way to add both annotations and meta-programming syntax to class declarations and members.
Parameter Decorators
Mango Framework provides some decorators that can be used on parameters.
@MangoRequest()@MangoResponse()@Param()@Player()(Only available inServer Enviroment)
Aditionally, you can create your own parameter decorators.
Creating a Parameter Decorator
Parameter decorators are declared just before a parameter declaration. To create a parameter decorator, you need to define a function that takes two parameters:
export const MangoCount = createParamDecorator((data, ctx) => {
const data = ctx.getMangoData();
return data.get('count');
});ts
Using a Parameter Decorator
@Controller()
export class DeliciousMangoController {
@On('growMangoes')
public onGiveMeMangoes(@MangoCount() count: number) {
console.log(`Growing ${count} mangoes`);
}
}ts
Working with Pipes
Custom parameter decorators can be used with pipes. For example, the following code uses the ParseIntPipe to parse the count parameter into a number:
@Controller()
export class DeliciousMangoController {
@On('growMangoes')
public onGiveMeMangoes(@MangoCount(new ParseIntPipe()) count: number) {
console.log(`Growing ${count} mangoes`);
}
}ts
Decorator Composition
Multiple decorators can be applied to a single declaration, as in the following examples:
export function Auth(...roles: Role[]) {
return applyDecorators(SetMetadata('roles', roles), UseGuards(AuthGuard, RolesGuard));
}ts
Then you can use it like this:
enum Role {
Admin,
User,
}
@Controller()
export class DeliciousMangoController {
@Auth(Role.Admin)
@OnClient('giveMeMangoes')
public onGiveMeMangoes(@Player() player: Player) {
player.giveMangoes(100);
}
}ts