lib/src/views/ViewEngineFactory.ts

import {Instantiable, FactoryProducer} from '../di'
import {ViewEngine} from './ViewEngine'
import {PugViewEngine} from './PugViewEngine'
import {ConfiguredSingletonFactory} from '../di/factory/ConfiguredSingletonFactory'

/**
 * Dependency factory whose token matches the abstract ViewEngine class, but produces
 * a particular ViewEngine implementation based on the configuration.
 */
@FactoryProducer()
export class ViewEngineFactory extends ConfiguredSingletonFactory<ViewEngine> {
    protected getConfigKey(): string {
        return 'server.view_engine.driver'
    }

    protected getDefaultImplementation(): Instantiable<ViewEngine> {
        return PugViewEngine
    }

    protected getAbstractImplementation(): any {
        return ViewEngine
    }
}