@t00nday/nestjs-mailer NPM

Nestjs Mailer

This is a mailer package built for nestjs leveraging the power of the observer pattern (i.e. Observable package). It is a simple nestjs API to the email-templates npm package which in turn uses nodemailer but simplified to use your preferred template engine. It also uses the juice npm package to inline the css from your css file.

Installation

Installation is as simple as running:

npm install -s @t00nday/nestjs-mailer email-templates

yarn add @t00nday/nestjs-mailer email-templates

Usage

A basic usage example:

This could be done synchronously using the register() method:

./app.module.ts

import { Module } from '@nestjs/common';
import { MailerModule } from '@t00nday/nestjs-mailer';

@Module({
    imports: [
        // ... other modules
        MailerModule.register({
            message: {
                from: 'test@example.org',
                // ...
            },
            // ...
        }),
    ],
})
export class AppModule {}

The module could also be registered asynchronously using any of the approaches provided by the registerAsync() method:

Examples below:

Using factory provider approach

./app.module.ts

// prettier-ignore
import { 
    MailerModule, 
    MailerModuleOptions 
} from '@t00nday/nestjs-mailer';
import { Module } from '@nestjs/common';

@Module({
    imports: [
        // ... other modules
        MailerModule.registerAsync({
            useFactory: (): MailerModuleOptions => ({
                message: {
                    from: 'test@example.org',
                    // ...
                },
                // ...
            }),
        }),
    ],
})
export class AppModule {}

Using class or existing provider approach:

./mailer-config.service.ts

import {
    MailerModuleOptions,
    MailerOptionsFactory,
} from '@t00nday/nestjs-mailer';
import { Injectable } from '@nestjs/common';

@Injectable()
export class MailerConfigService implements MailerOptionsFactory {
    createMailerOptions(): MailerModuleOptions {
        return {
            message: {
                from: 'test@example.org',
                // ...
            },
            // ...
        };
    }
}

The MailerConfigService SHOULD implement the MailerOptionsFactory, MUST declare the createMailerOptions() method and MUST return MailerModuleOptions object.

./app.module.ts

// prettier-ignore
import {
    MailerModule,
    MailerModuleOptions
} from '@t00nday/nestjs-mailer';
import { Module } from '@nestjs/common';

import { MailerConfigService } from './mailer-config.service.ts';

@Module({
    imports: [
        // ... other modules
        MailerModule.registerAsync({
            useClass: MailerConfigService,
        }),
    ],
})
export class AppModule {}

Inject the MailerService as a dependency:

./app.service.ts

import { Observable } from 'rxjs';
import { Injectable } from '@nestjs/common';

@Injectable()
export class AppService {
    constructor(
        // ...other dependencies...
        private readonly mailerService: MailerService,
    ) {}

    sendMail(): Observable<string> {
        this.mailerService.send({
            message: {
                to: 'receiver@example.org',
                // ...
            },
            template: 'welcome',
            // ...
        });
    }
}

Configuration

As mentioned above, this package is built as an API to the email-templates npm package hence the configuration is just the same as that of the original package. The bootstrap MailerModuleOptions is an alias for the EmailConfig (this can be found by intalling @types/email-templates usingnpm i -D @types/email-templates) declaration. This is properly documented here.

API Methods

As highlighted above, after registering the module, the MailerService is the gateway to access the module APIs hence, the instruction above to inject it into our class. This attempts to cover the methods provided by the mailer service - most similar to the implementations by the email-templates package and some not covered by the packages documentation.

The following methods share the same implementation architecture as the original packages so can be called as referenced in the email-templates package:

send<T = Record<string, any>(options: EmailOptions<T>): Observable<string>
juiceResource(html: string): Observable<string>
render<T = Record<string, any>>(view: string, locals: T): Observable<string>
renderAll(): Observable<string>

Other methods not documented in the package are detailed below:

getTemplatePath(template: string): Observable<string>: This returns the path to a template (the only string argument provided to the method). This is returned as a Observable<string>.
templateExists(view: string): Observable<boolean>: This return an Observable<boolean> indicating if a template for a view exists or otherwise.
checkAndRender<T = Record<string, any>>(type: keyof EmailMessage, template: string, locals: T): Observable<string>: This renders and returns Observable<string> if a template exists with the type (i.e. html, subject, text).

Further documentation and understanding of the email-templates package can be found on the packages documentation.