Compose responsive email templates easily, fill them with models, and send them out.
This is the stuff responsible for sending beautiful emails in Pony Foo. I've now isolated the code and made it into a reusable package, called campaign
. It comes with a dead simple API, and a beautiful responsive layout, originally written by MailChimp, adapted by me, and easily configurable.
It uses Mustache to fill out the email templates, and Mandrill to actually send the emails, although providing your own service to actually send the emails is easy.
Reference
Quick links for reference.
Getting Started
Install using npm
.
npm i --save campaign
Set it up.
Construct a client
.
var client = require('campaign')();
(the default client needs an API keep for Mandrill, read on)
Send emails!
client.send(template, options, done);
client.sendString('<p>{{something}}</p>', options, done);
(detailed information below)
Client Options
Here are the default options, they are explained below.
{
"mandrill": {
"apiKey": "<not provided>",
"debug": false
},
"from": "<not provided>",
"client": "<defaults>",
"trap": false,
"headerImage": "<not provided>",
"layout": "<defaults>"
}
trap
If true
, then emails won't be sent to any of the recipients, but they'll be sent to the provided trap
address instead. For example, you could set trap
to nico@bevacqua.io
, and all emails would be sent to me instead of the intended recipients. Great for spamming me, and also great for testing.
When you trap
recipients, the email will get a nifty JSON at the end detailing the actual recipients that would've gotten it.
mandrill
By default, the Mandrill service is used to send the emails. Mandrill is really awesome and you should be using it. It has a generous free plan.
At the time they host the source code in Bit Bucket, which is kind of cryptic, but you can read through it nonetheless.
You need to provide an API key in apiKey
, and that's all there is to it. You might prefer to ignore this configuration option, and merely set process.env.MANDRILL_APIKEY
. That works, too.
from
The from
address for our emails. The client
is responsible for trying to make it look like that's the send address. Not necessarily used for authentication.
client
You can actually use other email clients, providing your own. To do so, you need to provide a client
object. The client
object should have a send
function, which takes a model
, and a done
callback.
Given that I originally worked with Mandrill, the client
API is based on their API client. I'll add details upon request.
You may provide the full path to an image. This image will be encoded in base64
and embedded into the email as a heading. Embedding helps people view your emails offline.
This image should have a 3:1
ish ratio. For instance, I use 600x180
in my blog's emails.
layout
The layout used in your emails. Templates for email sending are meant to have the bare minimum needed to fill out an email. Since you want a consistent UX, the same layout
should be used for every email your product sends.
A default layout template
is provided. You can provide a different one, just set layout
to the absolute path of a Mustache template file. For information about the model passed to the layout, see the Templates section.
Email Sending Options
Once you've created a client, you can start sending emails. Here are the default options, and what you need to fill out.
{
"subject": "<not provided>",
"preview": "<options.subject>",
"to": "<not provided>",
"images": "<empty>",
"social": {
"twitter": "<not provided>",
"landing": "<not provided>",
"name": "<not provided>"
},
"mandrill": {
"tags": "<not provided>",
"merge": "<not provided>"
},
"styles": "<defaults>"
}
.send
vs .sendString
The only difference between .send
and .sendString
is that .send
takes the path to a file, rather than the template itself. .send
compiles the template and keeps it in a cache, while .sendString
compiles the template every time.
subject
The email subject.
preview
This is the line that most email clients show as the preview of the email message. It defaults to the subject line. Changing it is extremely encouraged.
to
These are the recipients of the email you're sending. Simply provide a single recipient's email address, or an array of email addresses.
images
If you want to provide the template with images other than the optional header when creating the campaign
client, you can provide a list of file paths and names (to reference them in your templates), as shown below.
[
{ name: 'housing', file: path.join(__dirname, 'housing.png')}
]
social
Social metadata used when sending an email can help build your brand. You can provide a twitter
handle, a name
for your brand, and a landing
page.
The name
is used as the name of the send address, as well as in the "Visit " link.
mandrill
Configuration specifically used by the Mandrill client.
Mandrill allows you to add dynamic content to your templates, and this feature is supported by the default Mandrill client in campaign
, out the box. Read more about merge variables.
mandrill.merge
Given that Mandrill's merge
API is fairly obscure, we process it in our client, so that you can configure it assigning something like what's below to mandrill.merge
.
{
"locals": [{
"email": "someone@accounting.is",
"model": {
"something": "is a merge local for the guy with that email"
}
}],
"globals": [{
"these": "are merge globals for everyone"
}]
}
Mandrill lets you tag your emails so that you can find different campaigns later on. Read more about tagging. By default, emails will be tagged with the template name.
styles
Read about styles below.
Templates
There are two types of templates: the layout
, and the email's body
template. A default layout
is provided, so let's talk about the email templates first, and then the layout.
Email body
Templates
The body
template determines what goes in the message body. The options we used to configure our email are also used as the model for the body
template, as sometimes it might be useful to include some of that metadata in the model itself.
The API expects an absolute path to the body
template.
client.send(body, options, done);
Other than the options listed above, you can provide any values you want, and then reference those in the template.
The layout
Template
The layout
has one fundamental requirement in order to be mildly functional, it should have a {{{body}}}
in it, so that the actual email's content can be rendered. Luckily the default layout
is good enough that you shouldn't need to touch it.
Purposely, the layout template isn't passed the full model, but only a subset, containing:
{
"_header": "<!!options._header>",
"subject": "<options.subject>",
"preview": "<options.preview>",
"generated": "<when>",
"body": "<html>",
"trapped": "<options.trapped>",
"social": "<options.social>",
"styles": "<options.style>"
}
In this case, the _header
would whether a header image was provided. Then, generated
contains the moment the email was rendered, using the 'YYYY/MM/DD HH:mm, UTC Z'
format string. Lastly, trapped
contains the metadata extracted from the model when trap
is set to true
, in the client options.
Styling the layout
These are the default styles
, and you can override them in the options
passed to client.send
.
{
"styles": {
"bodyBackgroundColor": "#eaeadf",
"bodyTextColor": "#505050",
"codeFontFamily": "Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, serif",
"fontFamily": "Helvetica",
"footerBackgroundColor": "#f4f4f4",
"headerColor": "#412917",
"horizontalBorderColor": "#dedede",
"layoutBackgroundColor": "#f3f4eb",
"layoutTextColor": "#808080",
"linkColor": "#e92c6c",
"quoteBorderColor": "#cbc5c0"
}
}
Unsubscribe Facilities
The default layout
supports an optional unsubscribe_html
merge variable, which can be filled out like below.
{
"merge": {
"locals": [{
"email": "someone@somewhere.com",
"model": {
"unsubscribe_html": "<a href='http://sth.ng/unsubscribe/hash_someone'>unsubscribe</a>"
}
}, {
"email": "someone@else.com",
"model": {
"unsubscribe_html": "<a href='http://sth.ng/unsubscribe/hash_someone_else'>unsubscribe</a>"
}
}]
}
}
That'd be a perfect use for merge variables, which were described above in the send options. Remember, those are just supported by Mandrill, though. They deal with those after you make a request to their API.
Here is a screenshot of an email sent using this library by the Pony Foo blog, in production.
Debugging
To help you debug, an alternative client
is provided. Set it up like this:
var campaign = require('campaign');
var client = campaign({
client: campaign.clients.console()
});
Rather than actually sending emails, you will get a lot of JSON output in your terminal. Useful!
Clients
There are a few clients you can use. The default client sends mails through Mandrill. There is also a console
logging client, explained above, and a nodemailer
client, detailed below.
Using nodemailer
To use with nodemailer
, simply use that client.
var nodemailer = require('nodemailer');
var smtp = nodemailer.createTransport('SMTP', {
service: 'Gmail',
auth: {
user: 'gmail.user@gmail.com',
pass: 'userpass'
}
});
var campaign = require('campaign');
var client = campaign({
client: campaign.clients.nodemailer({
transport: smtp,
transform: function (options) {
}
})
});
That's that.
Making your own client
If the existing clients don't satisfy your needs, you may provide your own. The client
option just needs to be an object with a send
method. For an example, check out the nodemailer
client source code.
You can easily write your own email sender, like this.
var campaign = require('campaign');
var client = campaign({
client: {
send: function (model, done) {
}
}
});
If you decide to go for your own client, campaign
will still prove useful thanks to its templating features.
License
MIT