CBC Radio App 2.0 iOS

CBC RADIO APP 2.0

Developer: Ash [email protected]

November 2010

Thursday, November 4, 2010

mailto:[email protected]

mailto:[email protected]

CBC Radio App 2.0 - iOS

CBC Radio App 1.0 for iPhone development started

in March 2009 - Released July 2009

No major updates since that date

Several hundred thousand downloads

High user satisfaction

Requests for background audio playback

History



Offer Radio 1, Radio 2, Radio 3, and TV Audio

Listen to live streams and music channels

Provide CBC podcasts

Favourite audio

View schedules

Find local frequencies

Embedded CBC.ca website

Functionality



Offer Radio 1, Radio 2, Radio 3, and TV Audio

Listen to live streams and music channels

Provide CBC podcasts

Favourite audio

View schedules

Find local frequencies

Embedded CBC.ca website

Functionality

Support iOS 4.x background audio and remote

Scaled iPhone version for iPad



Hmmm ... Boring! And not compelling



Designed for iPad, not a giant iPod Touch

Auto Lo / Hi bandwidth switching for 3G / WiFi

Tracked episode playback positions

Auto-play, Sleep timer, Alarm clock

Share Audio by Email, Facebook or Twitter

Embedded Radio 3 Website with native playback:

100,000 tracks on demand from 23,000 artists

These are personal ideas

Hmmm ... Boring! And not compelling



What differentiates a design-by-committee product

and one that exceeds expectations?

Personal attention

Alot of thought given to design, features; Humans

are emotional, so apps need to speak to our

emotions

Many minute adjustments to animations, colour

choices, layouts, font sizing, shades of grey

Hours and hours of testing, actively seeking bugs

Delivering Success

Can’t stress this enough !



One developer / producer on loan

One part-time designer

One product champion

Resources



One developer / producer on loan

One part-time designer

One product champion

Resources

NO project manager

NO specification!

3 months



Know your domain

Understand your audience

Be passionate

Explore, experiment

Get business support – product champions

Organise the work

Develop intelligently *

Iterate

Technical Process



CBC Radio 1.0

Interface completely coded – no Interface Builder

Controller, views, model mixed together, not MVC

No clear understanding of the problem domain

Over-engineered: localisation, caching

Plus... Lower the Technical Debt



CBC Radio 1.0

Interface completely coded – no Interface Builder

Controller, views, model mixed together, not MVC

No clear understanding of the problem domain

Over-engineered: localisation, caching

Plus... Lower the Technical Debt

CBC Radio 2.0 is an 85% rewrite

True MVC

Interface Builder when possible

Built on a reusable frameworkThursday, November 4, 2010


Employ strategy of “Sufficient Design”

Convention-over-configuration & reflection to map

XML data into Model objects

MVC enforced by the use of protocols

UIWebView for relative positioning

Reuse of iPhone UIViewControllers for iPad

Optimise only when needed

Technical Approach



A convention to map XML elements and attributes

to Class properties

Fetch and digest XML; use reflection to determine if

a Class has a property that can be set

(NSKeyValueCoding protocol)

Benefits:

Dynamic mapping – no glue code

Less code – easy maintenance and extension

The Model Layer



Multiple types of audio sources: Live Streams,

Music Channels, Podcasts, Audio from Websites

Plus multiple ways to present content visually

How to design?

If we use IF statements to differentiate between

types, we’re doing it wrong

Solution:

Design protocols that hide concrete classes

1 protocol for Audio playback, 1 for Visual display

Enforcing MVC



Write controllers that operate on the Audio Protocol

Build views that use content from the Visual Protocol

Enforcing MVC

Live Radio

Music Channels Podcasts

Website Audio

Audio Protocol Visual Protocol

Controllers and Views

Model



Interface Builder is good for:

basic resolution independence

orientation independence (important for iPad)

visual layout – can be used by designers

UIKit doesn’t permit relative positioning

So if you have UILabels with variable number of

lines, IB is difficult for relative layouts

One solution: use UIWebView, which supports

relative positioning

UI



Many views don’t need a custom interface for iPad

Use UIPopoverController to reuse iPhone

UIViewControllers

Also use Modal views – presentModalViewController

Reuse iPhone UIViewControllers for iPad



Classic issue – Business vs. Engineering:

Business wants a product as fast as possible at

lowest cost

Many places do not understand Software is an art

Developers want to craft great code – but that

takes time

Is a balance possible?

Approach to Architecture



Under-design: Quick as possible cowboy coding

Only thinking about 1.0 release

Spaghetti code, bad coding style, buggy

No abstraction, no MVC, or even OOP

Throwaway code

Over-design: Building for worst-case scenarios

Added layers of complexity (too much abstraction)

Longer development cycles

More code to maintain, ironically less agile

The Extremes



Spend time designing for critical components

Example: the protocol for audio playback

Don’t spend time over-designing for components

that provide zero or no value

Example: caching where it’s not needed

Assemble parts when possible, instead of building

from scratch. Lower initial costs, as well as future

maintenance.

Example: Audio playback engine is 3rd party

Balanced or “Sufficient Design”



“Sufficient” doesn’t mean “compromised”. It means

lean and more maintainable.

We are still responsible for proper MVC and OOP;

these are critical parts of the architecture.

How to do it?

Protocol for Audio playback was not planned, but

developed when it was needed – iteratively

In a given problem, use the maturity of your

skillset to lower technical debt

Sufficient Design Continued ...



*See Industrial Logic for more on Sufficient Design

Questions?


Documents

CBC Radio App 2.0 iOS