CFWheels Pragmatic, Beautiful code

Indy Nagpal Straker Software Melbourne, November 2010

A bit about me

•  CTO, Straker Software, New Zealand

•  Been doing CF (and Flex) for a while

•  Cloud-based CF Using Railo

•  In love with Ruby (the language) & Rails

– Was in love with Groovy (still am, I think)

•  nagpals.com/blog

Rapid ≠ Agile

Agile

•  Early, continuous delivery of software

•  Welcome changing requirements

•  Deliver working software frequently

•  Working software = progress

•  Technical excellence and good design

•  Simplicity is essential – work not done

“There comes a time in the history of every project when it becomes

necessary to shoot the engineers and begin production.”

Need

•  Quickly build and deploy database-driven web apps

•  Rapid iterations in a testable fashion

•  Easy for multiple developers to understand

•  Working app is more important than configuring the app

Search…

•  Tried lots of frameworks/methodologies

•  Ruby on Rails addressed most issues

•  Learn another language and framework

•  Defeats the whole purpose

•  Enter, CFWheels…

What is CFWheels

•  Framework inspired by Ruby on Rails

•  Simple organization system

•  Suited for typical, database-driven web applications

•  A couple of years’ old – fairly mature

Convention over configuration

•  Possibly the single most important thing

•  Mostly convention, minor configuration

•  Easy to

–  turn on

–  tune in

– drop out

Directory structure •  webroot – models– controllers– views

– images– javascripts– stylesheets

– plugins

– tests– events– config

Intuitive Code Structure •  View

–  Responsible for display and user interaction –  Receive data from controller

•  Controller –  Process requests from view –  Get/process data from model –  Make data available to the view

•  Model –  Interacts with the database layer –  Responsible for validation –  Other methods to process/message data

Convention - URLs

•  URLs mapped to controllers/models/views

http://blog/posts/edit/1Controller: Posts

Model: Post

Action: Edit

Key: 1

View – http://blog/posts/ /views/posts/index.cfm

<cfparam name="posts"><ul><cfoutput query="posts"><li> #linkTo( text = "#posts.title#", action= "edit", key = post.id, title = "Edit #posts.name#" )#</li>

</cfoutput></ul>

Controller – http://blog/posts/ /controllers/Posts.cfc

<cfcomponent extends="Controller"><cfscript>function index(){ posts = model("post").findAll(order="createdAt")}

</cfscript></cfcomponent

Model – http://blog/posts/ /models/Post.cfc

<cfcomponent extends="Model"><cfscript>function init(){ belongsTo("author") hasMany("comments") validatesLengthOf( properties = "title", minimum = 10, maximum = 255)}

</cfscript></cfcomponent>

Convention – Files & Database

•  Place in appropriate folders – MVC

•  Plural database names, singular model names

– DB Table: posts– Model: Post.cfc

•  Database fields: id, createdat, updatedat

Built-in ORM

•  Simple and elegant

•  All major databases supported

•  Almost no setup required – baked in

•  CRUD instantly available via models/plugin

•  Finding data using “finders” –  findOne(), findAll(), findByKey()…

Associations models/Post.cfc

<cfcomponent extends="Model"> <cfscript>

function init(){ belongsTo("author") }

</cfscript> </cfcomponent>

models/Author.cfc

<cfcomponent extends="Model"> <cfscript>

function init(){ hasMany("posts") }

</cfscript> </cfcomponent>

<cfscript>posts = model("post").findAll(include="author")author = model("author").findOneByKey(key=params.key,include="posts")

</cfscript>

Dynamic Finders

•  Dynamic finders are magical model("user").findOne(where="username='bob' and password='pass'")

rewritten as

model("user").findOneByUsernameAndPassword("bob,pass”)

URLs and Routing

•  Beautiful URLs –  http://blog/a-good-url

•  Powerful routing mechanism <cfset addRoute( name = "showPost",

pattern = "/[key]”, controller = "Posts", action = "show")>

•  Can be turned REST-full

Multiple response formats •  http://blog/posts

•  http://blog/posts.xml

•  http://blog/posts.json

•  http://blog/posts.csv

•  http://blog/posts.pdf

Common tasks done

•  Adding timestamps

•  Flashing messages

•  Pagination

•  Sending multi-part emails

•  Redirecting users

Lots of helper functions •  Views

selectBox()

linkTo()

timeAgoInWords()paginationLinks()

titleize()pluralize()

•  Model validatePresenceOf()

findAll()

findOneByKey()afterSave()

•  Controller flash()

isGet()sendMail()

Plugins

•  Neat architecture to add/override functionality

•  Extremely useful

– Scaffold –generate CRUD application

– DBMigrate – Add/edit database structure

– Remote Form Helpers – Ajax with forms

– Localizer – Localizing an application

Baked in testing

•  Ships with RocketUnit <cfcomponent extends="tests.Test"><cfscript>

function test_1_get_timezones(){ qTimezone = model("Timezone").getTimezones() assert("isQuery(qTimezone) ") assert("qTimezone.recordcount eq 56")}

</cfscript></cfcomponent>

Environments

•  Different setup for applications based on stages of development

– Design, Development, Production, Testing, Maintenance

•  Differ in terms of caching, error-handling

•  Switch environments via config/url

Docs/Support

•  Very helpful docs at cfwheels.org

•  Active and supportive mailing list

•  Quite a few screencasts

•  Direct knowledge transfer from Ruby on Rails books/docs (e.g., Head First Rails)

•  Bunch of blogs

IDE Support

•  Eclipse, CFBuilder

– Syntax Dictionary

•  Textmate

– Bundle

•  Coda

– Lacking, but works by adding Clips

Beauty

•  Simple code organization and flow

•  Easy to understand code – eyeballing code

•  Common tasks done with minimal code

•  Pretty URLs

•  Almost zero configuration, with power to configure as much as needed

Pragmatic

•  Focus on simple code that solves issues

•  Trades pure OO for simplicity and structure

•  Easy to not use the framework if needed

•  Common web application problems already solved – why reinvent the wheel(s)!

Wrap up

•  Evaluate if you need a ‘framework’

•  Learn URL rewrites (Apache, IIS)

•  Dabble with Ruby on Rails

•  cfscript = succinct code

•  Worth trying out just to see how problems can be solved in a different manner

Thank you

Questions?

indy@nagpals.comnagpals.com/blog