Creating a Mail Driver

Creating a Mail Driver

Introduction

Because of Masonite's Service Container, It is extremely easy to make drivers that can be used by simply adding your service provider.

Getting Started

Masonite comes shipped with a Service Provider called MailProvider which loads a few classes into the container as well as boots the default mail driver using the MailManager. This manager class will fetch drivers from the container and instantiate them. We can look at the MailProvider class which will gives us a better explanation as to what's going on:

class MailProvider(ServiceProvider):

    wsgi = False

    def register(self):
        self.app.bind('MailConfig', mail)
        self.app.bind('MailSmtpDriver', MailSmtpDriver)
        self.app.bind('MailMailgunDriver', MailMailgunDriver)

    def boot(self):
        self.app.bind('Mail', MailManager(self.app))

We can see here that because we are only binding things into the container and we don't need the WSGI server to be running, we set wsgi = False. Service Providers that set wsgi to False will only run when the server starts and not on every request.

We can see here that we are binding a few drivers into the container and then binding the MailManager on boot. Remember that our boot method has access to everything that has been registered into the container. The register methods are executed on all providers before the boot methods are executed.

Mail Manager

The MailManager here is important to understand. When the MailManager is instantiated, it accepts the container as a parameter. When the MailManager is instantiated, it fires a create_driver method which will grab the driver from the configuration file and retrieve a MailXDriver from the container. The create_driver method is a very simple method:

def create_driver(self, driver=None):
    if not driver:
        driver = self.container.make('MailConfig').DRIVER.capitalize()
    else:
        driver = driver.capitalize()

    try:
        self.manage_driver = self.container.make('Mail{0}Driver'.format(driver))
    except KeyError:
        raise DriverNotFound('Could not find the Mail{0}Driver from the service container. Are you missing a service provider?'.format(driver))

Notice that when the driver is created, it tries to get a Mail{0}Driver from the container. Therefore, all we need to do is register a MailXDriver into the container ('X' being the name of the driver) and Masonite will know to grab that driver.

Creating a Driver

So now we know that we need a MailXDriver so let's walk through how we could create a maildrill email driver.

We can simply create a class which can become our driver. We do not need to inherit anything, although Masonite comes with a BaseMailDriver to get you started faster and all drivers should inherit from it for consistency reasons. You can make your driver from a normal class object but it will be harder and won't be considered in Pull Requests.

Let's create a class anywhere we like and inherit from BaseMailDriver:

from masonite.driver.BaseMailDriver import BaseMailDriver

class MailMaildrillDriver(BaseMailDriver):
    pass

Great! We are almost done. We just have to implement one method on this class and that's the send method. All other methods like to and template are inherited from the BaseMailDriver class. You can find out how to send an email using Maildrill and implement it in this send method.

We can look at other drivers for inspiration but let's look at the MailMailgunDriver class now:

import requests
from masonite.drivers.BaseMailDriver import BaseMailDriver

class MailMailgunDriver(BaseMailDriver):

    def send(self, message=None):
        if not message:
            message = self.message_body

        domain = self.config.DRIVERS['mailgun']['domain']
        secret = self.config.DRIVERS['mailgun']['secret']
        return requests.post(
            "https://api.mailgun.net/v3/{0}/messages".format(domain),
            auth=("api", secret),
            data={"from": "{0} <mailgun@{1}>".format(self.config.FROM['name'], domain),
                  "to": [self.to_address, "{0}".format(self.config.FROM['address'])],
                "subject": self.message_subject,
                "html": message})

If you are wondering where the self.message_body and self.config are coming from, check the BaseMailDriver. All driver constructors are resolved by the service container so you can grab anything you need from the container to make your driver work. Notice here that we don't need a constructor because we inherited it from the BaseMailDriver

Registering Your Mail Driver

Since the MailManager class creates the driver on boot, we can simply register the driver into the container via any service providers register method. We could create a new Service Provider and register it there. You can read more about created Service Providers under the Service Providers documentation. For now, we will just register it from within our AppProvider.

Our AppProvider class might look something like this:

from your.driver.module import MailMandrillDriver
class AppProvider(ServiceProvider):

    wsgi = True

    def register(self):
        self.app.bind('WebRoutes', web.ROUTES)
        self.app.bind('ApiRoutes', api.ROUTES)
        self.app.bind('Response', None)
        self.app.bind('Storage', storage)

        # Register new mail driver
        self.app.bind('MailMandrillDriver', MailMandrillDriver)

    def boot(self, Environ):
        self.app.bind('Request', Request(Environ))
        self.app.bind('Route', Route(Environ))

Great! Our new driver is registered into the container. It is now able to be created with Masonite's MailManager class. We can retrieve your new driver by doing:

def show(self, Mail)
    Mail.driver('mandrill') # fetches MailMandrillDriver from container

Configuration

If we want the MailManager to use our new driver by default, change the DRIVER in our config/mail.py file. In addition, you may have the users of your driver require a special dictionary entry to the DRIVERS dictionary:

DRIVERS = {
    'smtp': {
        'host': os.getenv('MAIL_HOST', 'smtp.mailtrap.io'),
        'port': os.getenv('MAIL_PORT', '465'),
        'username': os.getenv('MAIL_USERNAME', 'username'),
        'password': os.getenv('MAIL_PASSWORD', 'password'),
    },
    'mailgun': {
        'secret': os.getenv('MAILGUN_SECRET', 'key-XX'),
        'domain': os.getenv('MAILGUN_DOMAIN', 'sandboxXX.mailgun.org')
    },
    'maildrill': {
        'secret': 'xx'
        'other_key': 'xx'
    }
}

This way, users can easily swap drivers by simply changing the driver in the config file.

That's it! We just extended our Masonite project and created a new driver. Consider making it available on PyPi so others can install it!