Function: Inject()

Call Signature

Inject<ClassPrototype>(): PropertyDecorator<ClassPrototype>

Inject into the property the object registered in the container under the property's name. The injection happens when the object is created, before its @Configurable properties are set and before its init() runs; it replaces a @Configurable declaration of the property in a parent class.

Type Parameters

ClassPrototype

ClassPrototype extends BaseObject

Returns

PropertyDecorator<ClassPrototype>

The property decorator.

Throws

When the object is created, if the registration cannot be resolved (the creation of the object rejects).

Example

import {Application, Component} from 'lakutata'
import {Inject} from 'lakutata/decorator/di'

class Mailer extends Component {
    public async send(to: string, text: string): Promise<void> {
        console.log(to, text)
    }
}

class Signup extends Component {
    //The component registered as "mailer"
    @Inject()
    protected readonly mailer!: Mailer

    //The object registered for the class (a class marked with @Autoload is registered on first use)
    @Inject(Application)
    protected readonly app!: Application

    //The component registered as "mailer", transformed: its send function bound to it
    @Inject('mailer', (mailer: Mailer) => mailer.send.bind(mailer))
    protected readonly send!: (to: string, text: string) => Promise<void>

    public async register(email: string): Promise<void> {
        await this.mailer.send(email, `Welcome to ${this.app.appName}`)
    }
}

Application.run(() => ({
    id: 'signup.app',
    name: 'Signup',
    components: {
        mailer: {class: Mailer},
        signup: {class: Signup}
    }
}))

Call Signature

Inject<ClassPrototype>(name): PropertyDecorator<ClassPrototype>

Inject into the property the object registered in the container under a name, or for a class. The injection happens when the object is created, before its @Configurable properties are set and before its init() runs; it replaces a @Configurable declaration of the property in a parent class.

Type Parameters

ClassPrototype

ClassPrototype extends BaseObject

Parameters

name

InjectionName

The registration name (a string or a symbol), or a class: the object registered for the class, which is registered on first use when the class is marked with @Autoload().

Returns

PropertyDecorator<ClassPrototype>

The property decorator.

Throws

When the object is created, if the registration cannot be resolved (the creation of the object rejects).

Call Signature

Inject<ClassPrototype>(transform): PropertyDecorator<ClassPrototype>

Inject into the property a value derived from the object registered in the container under the property's name. The injection happens when the object is created, before its @Configurable properties are set and before its init() runs; it replaces a @Configurable declaration of the property in a parent class.

Type Parameters

ClassPrototype

ClassPrototype extends BaseObject

Parameters

transform

InjectionTransformFunction

A function (not a class) receiving the registered object and returning the value set to the property; it may be async, the property then receives the value it resolves to.

Returns

PropertyDecorator<ClassPrototype>

The property decorator.

Throws

When the object is created, if the registration cannot be resolved (the creation of the object rejects); an error of transform rejects the creation as it is.

Call Signature

Inject<ClassPrototype>(name, transform): PropertyDecorator<ClassPrototype>

Inject into the property a value derived from the object registered in the container under a name, or for a class. The injection happens when the object is created, before its @Configurable properties are set and before its init() runs; it replaces a @Configurable declaration of the property in a parent class.

Type Parameters

ClassPrototype

ClassPrototype extends BaseObject

Parameters

name

InjectionName

The registration name (a string or a symbol), or a class: the object registered for the class, which is registered on first use when the class is marked with @Autoload().

transform

InjectionTransformFunction

A function receiving the registered object and returning the value set to the property; it may be async, the property then receives the value it resolves to.

Returns

PropertyDecorator<ClassPrototype>

The property decorator.

Throws

When the object is created, if the registration cannot be resolved (the creation of the object rejects); an error of transform rejects the creation as it is.