How to call Hapi plugin function from another - node.js

Question

In Hapi (v17 if it makes any difference), what is the correct way to call a function in a plugin from another ?
Let's say I've started writing a wrapper plugin around Nodemailer :
'use strict';
const Nodemailer = require('nodemailer');
exports.plugin = {
name: 'mailerWrapperPlugin',
version: '0.0.1',
register: async function (server, options) {
}
};
What would be the correct way to expose plugin functions elsewhere in Hapi (i.e to the Hapi instance itself, but perhaps more importantly, to other plugins loaded by Hapi).
I'm finding the Hapi documentation a bit sparse, especially in relation to plugins.
So, for example, if my Nodemailer wrapper had a sendMail() function, how would I make that available in another plugin I've written ?
P.S. I'm a bit of a Node.JS/Hapi newbie, so treat me gently ! I'm testing this out because I'm thinking of migrating from PHP to Hapi for future backend applications.

Answer 1

You can use server.methods object. The doc says:
Server methods are functions registered with the server and used
throughout the application as a common utility. Their advantage is in
the ability to configure them to use the built-in cache and share
across multiple request handlers without having to create a common
module.
Now this is your first plugin:
const Nodemailer = require('nodemailer');
exports.plugin = {
name: 'mailerWrapperPlugin',
version: '0.0.1',
register: async function (server, options) {
server.method('sendMail', (subject, to, body) => {
// compose and send mail here
});
}
};
and this is your second, and make sure this is loaded after the first one.
exports.plugin = {
name: 'anotherPlugin',
version: '0.0.1',
register: async function (server, options) {
server.methods.sendMail("Hello", "test#test.com", "Sup?");
}
};
That's it.
Also you can use server.decorate object as well. Its doc says:
Extends various framework interfaces with custom methods where:
server.decorate may add methods to several other objects like routes, request, server and response object.
If we go back to your plugin:
exports.plugin = {
name: 'mailerWrapperPlugin',
version: '0.0.1',
register: async function (server, options) {
server.decorate('server', 'sendMail', (subject, to, body) => {
});
}
};
and your second plugin which was loaded after the first one!
exports.plugin = {
name: 'anotherPlugin',
version: '0.0.1',
register: async function (server, options) {
server.sendMail("Hello", "test#test.com", "Sup?");
}
};
The difference between them, the server.methods object add custom fields to server.methods object but with the server.decorate you can directly extend your server or request objects. Use which one is more clear to you, I prefer server.decorate generally.