Development @ MgX Presentation -...

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Development

@ MgX

1

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Agenda

Application Overview

Smalltalk

Model Driven Development

Automated Testing

Agile Software Development

2


Agenda

Central theme:

“Automate repetitive work”

Humans are not good at it3


Agenda


Smalltalk


Automated Testing


4



WHATS‟On

Client – Server Application

Client = Smalltalk

Server = Oracle Relational Database

5



1.6 Million Lines Of Code

+12.000 Classes

+4.500 System Classes

190.000 Methods

6



600 database tables

9000 table columns

40+ million rows of data

200 concurrent users

7



+30 Customers

500 TV Channels

4000 Users

8



Software Product

Product(12.000 classes)

9



Customisations


MTV50 classes

10



Many customisations


MTV50 classes

VRT100 classes

RTBF20 classes

VT4200 classes

VTM250 classes

YLE/fi300 classesTV2/dk

120 classes

NRK/No500 classes

Pro7/ger600 classes

11



Multi Language

300 Application Windows

40 Optional Modules

12



Conclusion

Large Application

Non Trivial

13


Agenda


Smalltalk


Automated Testing


14


Smalltalk

Smalltalk?

15


Smalltalk

Wikipedia:

“Object oriented, dynamically typed,

reflective programming language”

Created during the 70s16


Smalltalk

Dynamically Typed

exampleMethod

| a b |

a := „Hello ‟.

b := „World‟.

^a, b

„Hello World‟

17


Smalltalk

Everything is an object

Every class can be extended

Integer>>abs

^ self < 0

ifTrue: [0 - self]

ifFalse: [self]

18


Smalltalk

-5 abs

Integer>>abs

^ self < 0

ifTrue: [0 - self]

ifFalse: [self]

-5

19


Smalltalk

Code is an object – a “BlockClosure”

anArray do: [:item | item doSomething]

In Scheme:

(lambda(item) (…))

Java is working on this

20


Smalltalk

Easy to read

persons do: [:each | ...]

21


Smalltalk

“Sort all persons alphabetically on

firstName”

persons sortedOn: #firstName

22


Smalltalk

“Which persons are married?”

persons select: [:each | each isMarried]

23


Smalltalk

“How old is the oldest person?”

persons max: [:each | each age]

24


Smalltalk

Code is read many times…

…reading it should be easy

25


Smalltalk

Smalltalk is written in itself

Classes

Methods

Compiled code

Objects that can be accessed by your own

code

Very good reflection capabilities

26


Smalltalk

Incremental Compilation

Smalltalk system is „alive‟

Your code is always running

Code changes take effect immediately

No compilation/build wait times

Huge timesaver

27


Smalltalk

Easy to dynamically generate code

Used for performance tuning[:t1 :t2 :t3 :t4 :t5 :t6 |

| t7 |

t7 := t2 at: t3.

t1 basicStateAt: 1 put: t7.

(t7 := t2 at: t3 + 1) == nil ifFalse: [t7 := t5 unprotectedObjectStateOrProxyForStorageClassIndex: 125 basicId: t7].


(t7 := t2 at: t3 + 2) == nil ifFalse: [t7 := t5 unprotectedObjectStateOrProxyForStorageClassIndex: 125 basicId: t7].


t7 := t2 at: t3 + 3.


t7 := t2 at: t3 + 4.


t7 := t2 at: t3 + 5.


t7 := t2 at: t3 + 6.


t7 := t2 at: t3 + 7.

t1 basicStateAt: 8 put: t7]28


Smalltalk

Garbage Collector

29


Smalltalk

IDE is written in Smalltalk

Source code is available

Easily extensible

Keyboard Shortcuts

Change the Compiler

30


Smalltalk

Very good debugger

Easily extensible

Write code in the debugger

31


Smalltalk

Is Smalltalk better than the rest?

I wouldn‟t say that

It was a given

Product started early „90s

A failed attempt to move to Java

Smalltalk has very interesting features

32


Agenda


Smalltalk


Automated Testing


33


Development

Database interaction

Building user interfaces

Customer specific changes

34


Development

Model driven approach

Use meta information about domain model to

automate tasks and to promote reuse

35


Example Model

Requirements:

User interface for editing

Store in relational database

Possibility to export as XML file

36


User Interface

37


Database

Select * from person;

38


XML

<Person>

<firstName>Angelina</firstName>

<lastName>Jolie</lastName>

<birthDate>04/06/1975</birthDate>

<isMarried>Yes</isMarried>

</Person>

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Framework – Super Model

Super Model

XMLUser Interface

Database

40


Super Model

Person>>buildSuperModelWith: aBuilder

aBuilder

dbTableName: „Person';

xmlTagName: 'Person'.

aBuilder

addString: #firstName dbName: 'firstName' uiName: 'Voornaam' xmlTag: 'firstName';

beMandatory;

addString: #lastName dbName: 'lastName' uiName: 'Familienaam' xmlTag: 'lastName';

beMandatory;

addDate: #birthDate dbName: 'birthDate' uiName: 'Geboortedatum' xmlTag: 'birthDate';

addBoolean: #isMarried dbName: 'isMarried' uiName: 'Getrouwd' xmlTag: 'isMarried' initialValue: false

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Super Model

XMLUser Interface

Database

42


DB Mapping

Generate DB creation scripts

create table person(

firstname varchar2(100) not null,

lastname varchar2(100) not null,

birthdate date,

ismarried number(1,0));

43


DB Installation

Used to be manual work

Full of bugs

Huge time saver

44


DB Mapping

Put objects into databasedbSession inTransactionWhile: [

person := Person new.

person firstName: „Angelina‟.

person lastName: „Jolie‟].

INSERT INTO person(oid, firstName, lastName)

VALUES (12345, „Angelina‟, „Jolie‟);

45


DB Mapping

Read objects from DB

Person retrieveWhere: [:each |

(each firstName = „Angelina‟) &

(each isMarried)]

SELECT * FROM person

WHERE firstName = ‘Angelina’ AND isMarried = 1;

46


DB Installation

Automation possible because of meta

information

Automate repetitive work

47


Framework – SuperModel

Super Model

XMLUser Interface

Database

48


User Interface

49


Super Model

Use information in SuperModel

No UI “painter”

50


Super Model

addString: #firstName dbName: „firstName' uiName: „Voornaam' xmlTag: „firstName';

addBoolean: #isMarried dbName: „isMarried' uiName: „Getrouwd' xmlTag: „isMarried';

51


Form Panel

| panel |

panel := self newFormPanel: 1.

panel

addFormEntryFor: #firstName;

addFormEntryFor: #lastName;

addFormEntryFor: #birthDate;

addFormEntryFor: #isMarried.

^panel

52


Form Panel

Adding fields is easy

| panel |


panel



addFormEntryFor: #hobby;



^panel

53


Form Panel

Customisations?


MTV50 classes

54


Form Panel

Customisations?


MTV50 classes

We want a „Hobby‟ field

55


Customer Specific Layout

Standard Product/All customers

MTVExtra field „Hobby‟

56



57



Customer specific layouts

| panel |


panel


addFormEntryFor: #lastName.

self addCustomerSpecificFieldsTo: panel.

panel



^panel

58



addCustomerSpecificFieldsTo: aFormPanel

aFormPanel addFormEntryFor: #hobby

addCustomerSpecificFieldsTo: aFormPanel

“Do nothing”

59



Customer specific layouts

| panel |


panel


addFormEntryFor: #lastName.


panel



^panel

Will add a #hobby field for MTV customer

60



All customers

MTVExtra field „Hobby‟

61



If product evolves, MTV will evolve too

| panel |


panel



addFormEntryFor: #address.


panel



^panel62


Multi Language UI

63


Multi Language UI


aBuilder



aBuilder


beMandatory;


beMandatory;


addBoolean: #isMarried dbName: 'isMarried' uiName: 'Getrouwd' xmlTag: 'isMarried'

initialValue: false;

64


Multi Language UI

65


UI

SuperModel rules applied in *every*

application window

Write once – reuse many times

Avoid repetitive work

66



Super Model

XMLUser Interface

Database

67


Super Model


aBuilder



aBuilder


beMandatory;


beMandatory;


addBoolean: #isMarried dbName: 'isMarried' uiName: 'Getrouwd' xmlTag: 'isMarried' initialValue: false

68


XML

aPerson asXML

„<Person>

<firstName>Angelina</firstName>

<lastName>Jolie</lastName>

<birthDate>04/06/1975</birthDate>

<isMarried>Yes</isMarried>

</Person>‟69


XML

70


XML

71


Development Conclusion

Meta information

Automate database interaction

UI building

Reuse UI logic

XML

End-user tools that navigate through model

72


Agenda


Smalltalk


Automated Testing


73


Automated Testing

How can you guarantee that your software

keeps on running when changes are made to

the code?

74


Automated Testing

Manual testing…

75


Automated Testing

Manual testing…

…1.6 million lines of code

76


Automated Testing

Manual testing…


…and +30 customers

77


Automated Testing

Manual testing…


…and +30 customers

…repetitive work 78


Automated Testing

Automated Testing

Let the computer do the testing for you

79


Automated Testing

“TestCase classes” (JUnit, SUnit)

InvoiceTestCase

PersonTestCase

…

+1.300 TestCase classes

+20.000 test_<something> methods

80


Automated Testing

81


Automated Testing

Acceptance tests

Test the application logic from the point of view of

an end user

No individual methods

Complete flow from user interface to database and

back

We have lots of them (+20.000)

82


Automated Testing

test_editPerson

| person|

person := self personPopulator createPersonWithFirstName: „Angelina‟ lastName: „Jolie‟.

self deny: (Person

existsWhere: [:person | (person firstName = „Bruce‟) & (person lastName = „Willis‟)]).

PersonEditor openOn: person.

self editField: #firstName value: „Bruce‟.

self editField: #lastName value: „Willis‟.

self toolBarPress: #saveCommand.

self assert: (Person

existsWhere: [:person | (person firstName = „Bruce‟) & (person lastName = „Willis‟)])

83


Automated Testing

84


Automated Testing

test_editPerson

| person|

person := self personPopulator createPersonWithFirstName: ‘Angelina’ lastName: ‘Jolie’.

self deny: (Person








85


Automated Testing

test_editPerson

| person|


self deny: (Person

existsWhere: [:person | (person firstName = ‘Bruce’) & (person lastName = ‘Willis’)].







86


Automated Testing

test_editPerson

| person|


self deny: (Person








87


Automated Testing

88


Automated Testing

test_editPerson

| person|


self deny: (Person



self editField: #firstName value: ‘Bruce’.

self editField: #lastName value: ‘Willis’.




89


Automated Testing

90


Automated Testing

test_editPerson

| person|


self deny: (Person







existsWhere: [:person | (person firstName = ‘Bruce’) & (person lastName = ‘Willis’)])

91


Automated Testing

Typical scenario

Set up initial data

Assert that the condition you‟re going to test is

NOT met

Do some stuff

Assert that the condition you‟re going to test IS met

92


Automated Testing

Regression tests

If someone inadvertently changes behavior the

tests should detect it

93


Automated Testing

They are crucial

You cannot manually test a large

application

94


Automated Testing

+20.000 automated tests

Takes 8 hours to run!

95


Automated Testing

Parallel execution

16 computers

30 minutes to get results

DEMO “Autoblader”

DEMO “Test Slave”96

autoblader.mp4

autoblader_slave.mp4


Automated Testing

Integrated into IDE

97


Tests

Extra work!

30% of total source code

98


Tests

Development time x2

99


Tests

Tests need to be maintained

Functionality changes

tests need to be changed

100


Tests

Pays back in the long run

Write once, reuse many times

101


Tests

Conclusion

Automated – avoid repetitive work

Crucial

Impact on project time

102


Agenda


Smalltalk


Automated Testing


103



25 Developers

10 Analysts

30 Customers wanting new stuff

Product itself has to evolve too

104



How do you organise this?

105




106



Group of software development

methodologies

“Lightweight”

107



Based on natural principles

Ask customer what he wants

Regularly show him what you made

Continuously ask his feedback

Customer gets what he wants

108



Agile Manifesto

Individuals and interactions over processes and tools

Working software over comprehensive documentation

Customer collaboration over contract negotiation

Responding to change over following a plan

109



Example implementations

Scrum

Extreme programming (XP)

110



Not always that easy

Customers don‟t want to be

bothered all the time

They have a real job to do

111



Customers live in another country

112



Customers don‟t want to install

and test a new version every

day

113



Customers want contractual

agreement

Required functionality

Deadline

Fixed price

114



How do you solve this?

115



Proxy Customer

Knows everything about the

customer

116



Analyst = Proxy Customer

3 analysts for every 10 customers

They talk with development team

They give demo‟s to customer

117


Scrum

How do we work on a project?

SCRUM

118


Scrum

Divide work into “sprints”

2 weeks

Divide sprints into “user stories”

1-3 days of work

All tests should be running

119


Scrum

120


Scrum

Every day status meeting

Daily Scrum

Stand-up meeting

121


Scrum

122


Scrum

123



Extreme Programming (XP)

124


Extreme programming

Code Reviews

125


Extreme programming

Code Reviews

Somebody else reviews your code

You can work concentrated

You get the chance to learn things, try things out

*Before* it gets published in code repository

126


Extreme programming

Code Reviews

We only review beginners code

Not enough time to review everything

127



Conclusion

SCRUM

XP

Code Reviews

128


Final conclusion


Smalltalk


Automated Testing


129


Thank you

130


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