feature driven development

@hendrikEbberswww.guigarage.com

Feature Driven Development


default branchAbout me

Hendrik Ebbers @hendrikEbbers

www.guigarage.com

JUG DortmundMastering JavaFX 8 Controls

DataFX, AquaFX, Vagrant-Binding


default branchContent

features workflows feature toggles


default branchWhat is a feature?

„play“ button feature


private single developer project

Ribbon interface removed

„play“ button added

multi touch support Hibernate version

changed


structure of a complex application

Backend

Frontend / UI

Persistence


Let’s start with the UI

trunk

button on UI


Diff of the first commit

<form > <input type="button" value=„play“ onclick=„rpc.play()“> </form>

class PlayService { ! public void play() { throw new RuntimeException(„Not implemented!“); } !}


Commit history

button on UI

JPA classes

new media service

bugfix #235

trunk


Houston, we have a problem

button on UI

JPA classes

new media service

bugfix #235

Application can’t be released!

trunk


Concurrent development = Concurrent problems

Jim

Bob

Martin

John

bugfix 7

new middleware

rest services

security issues



button on UI

JPA classes

new media service

bugfix #235

trunk

Ribbon interface removed (50%)


testcommit

refactored most entities



button on UI

JPA classes

new media service

bugfix #235

trunk



testcommit

refactored most entities

Application can NEVER be released!


Using a feature branch

button on UI

JPA classes

new media service

mergebranch

develop

feature branch


Release cycle?

Application can be released!


Concurrent development?


feature 1

feature 2


Problem: merge hell


merge hell

f# 1 f# 4 f# 2 f# 3 f# 5

t = 2 month



hidden button and middleware

backendvisible button

easy merge

easy merge

easy merge

Solution: Dark launching & small branches


Solution: update the feature branch


merge merge merge

adding button

localization of button title

final button icon

!easy merge / pull request


Problem: changes creates bugs


bugs?

Point of no return


Solution: Feature Toggles

!

if(MY_FEATURE.isActive( )) {

showPlayButton( );

} activate feature

the featurecheck


Fallback to old implementations

!

if(NEW_PERSISTENCE.isActive( )) {

return jpaCall( );

} else {

return jdbcCall( );

}old new


Java APIs

JSF Support

Spring Support Java EE

SupportAdmin Console

Activation Strategies

State Repositories

User Authentification

Java SE Support


Java APIs

JavaFX Support

Observer pattern

Binding Supports

predefined annotations


Define Features as enum

!

@Issue(„JFX-638“)

@EnabledByDefault

NEW_PERSISTENCE,

!

@Issue(„JFX-492“)

@EnabledByDefault

TWITTER_SUPPORT,

. . .

add metadata to describe the

feature


Features state and activation

!

MY_FEATURE.isActive( )

always

always on dev system

next 3 hours

for random users

stored in db

defined in property file


Administration view

< >

!http://www.my-app/administration/togglz


Fronted support

!

<h:panelGroup rendered="#{features['PLAY_FEATURE']}">

<h:commandButton value=„play" />

</h:panelGroup>

@FXML

@HideByFeature("PLAY_FEATURE")

private Button playButton;

JavaFX

JSF


Take care of your features

FEATURE_1,

FEATURE_2,

FEATURE_3,

FEATURE_4,

FEATURE_5,

. . .

FEATURE_1462,

FEATURE_11463,

Where is my

feature???

Don’t forget

to clean up!(once a feature is

live for a defined

period of time)


Conclusion

button & feature toggle

backendremove

feature toggle

use feature toggles

clean upuse short living

branches

describe your

features with

metadata&

provide

feature

administration&

@YourTwitterHandle#DVXFR14{session hashtag} @hendrikEbberswww.guigarage.com

Q&A

feature driven development

Technology

feature branch button

feature branch application

ui trunk button

merge merge merge

play button

feature check

problem button

concurrent problems