Meteor

A platform to develop modern applications faster than you ever thought

José Cabo Carsí josecabocarsi@gmail.com @JoseCaboCarsi /in/josecabo

We are going to cover about...

1. What is Meteor
2. Database. Everywhere.
3. Blaze & templating
4. Securing our application
5. Latency Compensation
6. Publish and subscribe
7. Let’s embrace the platform

But we will not cover...

• Deploying our web application
• Mup: https://github.com/arunoda/meteor-up
• User accounts:
• https://www.meteor.com/try/9
• http://docs.meteor.com/#/basic/accounts
• Routing (iron-router):
• https://github.com/iron-meteor/iron-router
• Mobile app creation

Typical application workflow

MVC in server - Symfony2

Routing

Controller

Templating

Browser

Html

+ javascript

Ajax!

Model

Server basic MVC - REST

Ajax!

Routing

Controller

Templating

Model

Imperative/conventional style Coding

• Code how to get your data
• Code from where to get it
• CRUD the interface with your data

What is Meteor?

The 10th of the most starred github project at date

​

The 6th of javascript projects

What is Meteor?

• Javascript everywhere
• One code to rule them all (uses node.js as its own framework)
• Web applications and web apps

What is Meteor?

• Client-server integration
• No callback-hell
• Automatisms (F5, minification, etc)
• Several subprojects
• MongoDB
• Hot-updates

Installing meteor

$ curl https://install.meteor.com/ | sh

$ meteor create <application-name>�$ cd <application-name>

$ MONGO_URL=mongodb://localhost:27017/your_db meteor

http://www.meteor.com

Reactivity? Uh?

• Vars: a := 3, b := 2
• c := a + b
• Result: c := 5

​

If after: b := 3

• Result: c := 5

(Unless explicit reexecution)

With Reactivity:

​

If after: b := 3

• Result: c := 6

More

• https://www.discovermeteor.com/blog/reactivity-basics-meteors-magic-demystified/

​

​

Meteor’s Full-Stack Reactivity

(client)�Minimongo

Server

(client)�Minimongo

Meteor data platform

MongoDB and minimongo

• Database everywhere

Real-time and multi-client data, by default

//Client

//Other client

MongoDB and minimongo

More about mongoDB

• http://docs.mongodb.org/manual/core/data-modeling-introduction/
• http://docs.mongodb.org/manual/core/crud-introduction/

​

Blaze & templating

• Spacebars, Meteor's dialect of Handlebars
• Logic-less template engine
• Super Ultra reactive

Blaze & templating

• Blaze reactivity works thanks to template’s helpers
• Reactively, they keep the interface updated

Events and meteor sessions

Tips

• When coding the layout try to represent a data state
• Never store the current interface state in DB

More

• https://github.com/meteor/meteor/blob/devel/packages/spacebars/README.md

Securing our application

Reasons:

• Never trust the client
• Data verification
• Secret server code
• ...

Revokes all client’s database writes

Securing our application

Special directories:

• client/
• server/

​

• */client/
• */server/

Securing our application

Securing our application

Securing our application

Problems:

• Network latency
• User Interface is not updated instantly
• Bad feedback to user
• Against everything we have already seen

Latency Compensation

It is possible to avoid network latency

​

• It simulates an execution in the client to predict server’s answer
• The UI updates instantly (delay = 0)
• After, if the simulation is correct, the UI remains the same

Latency Compensation

Two different codes:

• Real in /server
• Simulation in /client

Same code in both sides.

More

• https://www.discovermeteor.com/blog/latency-compensation
• https://www.discovermeteor.com/blog/advanced-latency-compensation/
• https://www.discovermeteor.com/blog/meteor-methods-client-side-operations/

Publish and Subscribe

So… the entire database is present in the client?

Where is all my data?!

Publish and Subscribe

To execute only in server

To execute only in client

• Accepts parameters

​

• Used to know when data is available in client

More

• http://meteortips.com/tutorial/publish-subscribe-autopublish/
• https://www.discovermeteor.com/blog/template-level-subscriptions/ (little bit old, but still nice)
• http://docs.meteor.com/#/full/Blaze-TemplateInstance-subscribe

Embrace the platform

ATMOSPHERE: https://atmospherejs.com/

$ meteor add repo:name

Embrace the platform

• accounts-ui
• accounts-password
• iron:router
• aldeed:collection2
• msavin:mongol

Warning!:

• insecure
• autopublish

More

• https://github.com/iron-meteor/iron-router
• http://www.manuel-schoebel.com/blog/iron-router-tutorial
• http://meteortips.com/book/accounts/

Embrace the platform

DDP client

DDP Server

DDP client

Meteor platform

(over websocket)

DDP

(over websocket)

DDP

Livequery

More

• https://github.com/meteor/meteor/blob/devel/packages/ddp/DDP.md
• https://www.meteor.com/ddp
• http://meteorpedia.com/read/DDP_Clients

Easy deploying

$ meteor deploy <destination>

http://<destination>.meteor.com

Free and automatic meteor host

More

• https://github.com/arunoda/meteor-up

Thanks!

By Francisco López