@alvaro_sanchez - Odobo

Álvaro Sánchez-Mariscal

Developing SPI applications using Grails and AngularJS

About me

• Passionate software developer.

• Founded Salenda in 2005.

• Co-founded Escuela de Groovy in 2009.

• Groovy/Grails lover since 2007.

• Working now at Odobo.

• HTML5 games platform for:

• Game developers.

• Casinos.

Typical Grails Architecture

This is about architecture.Grails is essentially MVC.This can be fine for some projects, but may have drawbacks in large projects

Monolithic!

Although the individual Grails artifacts can be developed in a modular way, it still has the views and the business logic on the same artifact.

Slow GSP rendering!

Slow startup time!

Memory consumption, reloading issues...

Sitemesh and the GSP rendering engine it’s not the fastest thing in the world...Large projects may suffer slow startup times, intensive resource usage, ....

Other problems

• It’s tricky to decouple the view layer to render views for different devices.

• It’s difficult to do frequent deployments.

• It’s hard to scale development.

Although there are plugins to solve this, it’s not that agile to have different renderings for different devices.Changes on the UI will require to redeploy the whole thing.The development efforts must be synchronized.

Grails 3.0 will have application profiles

The Grails roadmap is already embracing the change, and 3.0 will offer different profiles:- Classic MVC.- Netty.- Vert.x.- Etc.

So... WTF is a Single Page Application?

SPI or SPA.

• A webapp where you can navigate without any page refresh.

• Ajax/REST is used to communicate with the server.

• The MVC is in the browser, written in Javascript.

Did you say Javascript??

Seriously??

WTF!?!?

I like Javascript!

Oh yeah me too!

I’m fine with Grails. Why should I care

about SPI?

• It’s faster.

• It has better user experience.

• It may be easier for the developer.

• How to gracefully degrade?

• How to deal with communication failures?

• Can I use the application offline?

• Do I need to duplicate the MVC?

The applications are usually faster and more responsive, so the user experience is better.It may be easier for developers, as they don’t need to deal with callbacks, the views are updated automatically.----What if there is no Javascript enabled?How to handle network issues?Are we going to have duplicated efforts?

• You get ready to expose a public API.

• It allows you to update the UI frequently.

• It’s easier to create mobile apps.

• You can organize/scale your teams better.

Other benefits

Separating the view you get ready for exposing an API.The UI can be redeployed frequently, without affecting the platform.It’s easier to create different views, for different devices.The dev teams can be reorganized and some development can be done in parallel.

You got me!! How can I do that with Grails!!

• Use Grails 2.3 REST capabilities.

• Define your backend: GORM? Other web services?

• Make it a robust, powerful black box for the front end.

Grails 2.3 comes with significant improvements to build REST API’s.You can still use all Groovy ecosystem to consume any backend.Then, you can concentrate on building a robust, tested, black boxed Grails layer.

• Focus on:

• Transactions.

• Efficient data manipulation.

• Security.

• Scalability.

What are the alternatives for the

client side?

AngularJS, Ember, Backbone...

todomvc.com

• Todo app implemented in lot of frameworks

Similar featuresGrails AngularJS

Domain class Model

GSP’s and templates Views and templates

${} {{ }}

Controllers Controllers

URL Mappings Routing

Grails & Angular

• Angular will issue an OPTIONS request as per CORS:

• Use cors plugin.

• Manually configure URL mappings to avoid 405 responses.

Demo

@alvaro_sanchez - Odobo

Álvaro Sánchez-Mariscal

Developing SPI applications using Grails and AngularJS