Frameworks - - PowerPoint PPT Presentation

Frameworks

• Some material from Ciera Jaspan,

Bill Scherlis, Travis Breaux, and Erich Gamma

Terminology: Libraries

• !
• "#
• "#

Library

Terminology: Frameworks

• $!%!

&

• $!
• '
• $!!
• $!!
• "()*+,+-.

Framework

• But this is an

application! Hey, wasn’t this a library?

More terms

• /''/0

!

• "/
• '&!
• '&!
• 1#!

#'

More terms

• "#2

/

• !'!

&

• !3

'2' '

Using an API

• !'
• $!
• 4'#
• !!

'

Google’s Map.Reduce

• ''''

Input key.value pairs Intermediate key.value pairs Output key.value pairs map : (k1,v1) list (k2,v2) reduce : (k2,list(v2)) list (v2)

• 1#
• 56%07
• 507
• 5087

8 9:

Google’s Map.Reduce

• ;

Input key.value pairs Intermediate key.value pairs Output key.value pairs map : (k1,v1) list (k2,v2) reduce : (k2,list(v2)) list (v2)

• /!<(!<
• =<
• <

Some Benefits of Map.Reduce

• &
• >>>0
• #
• ''
• ''
• '
• $

Constraints

• ? '
• @%'
• ='#'

'<

Hadoop: Map.Reduce in Java

• AA--'A

: An Eclipse Plugin

• B /*1
• @'0!

)'0' ''-.

• '!8C/
• '@
• '

@4->

• @1'

@1,:

• >->

'--0 '---0 '--3-#0

$!

• D>>EB
• @

'--3-#0 '--- &

• B 1-F

: An Eclipse Plugin

• '-#
• @'
• G@
• #
• 1#
• #

'---

• #

H<# :I->I':I6"$JI<K H< :IL-I<K H'K H# :I'---IK H :IG@1I #:I#I

$! L

• D>>EB
• #
• 2
• '#

0-M

#:I#I :IA-') :I'---#-N "#1I :I--G@1I :I--G@1IK HAK HA#K HA'K

: An Eclipse Plugin

• 0M
• G@1-3
• /"#1
• 00 000

AA0A0O

• %1P?/1
• N /"#1
• !"

$!

• D>>EB
• 1##'''
• G@*

'

• G@'
• !"

" #$% #$% &

• &

&

: a JUnit Plugin

public class SampleTest { private List<String> emptyList; @Before public void setUp() { emptyList = new ArrayList<String>(); } @After public void tearDown() {

Here the important plugin mechanism is Java annotations

$!

• D>>EB

public void tearDown() { emptyList = null; } @Test public void testEmptyList() { assertEquals("Empty list should have 0 elements", 0, emptyList.size()); } }

The Golden Rule of Framework Design

• 1#'!?8"2'

!M

• *#<
• 570'0!
• $!570'
• $!570'
• 1-'-''

:-'57-5'Q>R7, ':-/57,

• $!!'
• 'B%

Java Swing: It’s a Library!

• C6/'
• B$0B0B*'0B@N
• 6''&
• B0B"#$0BN

"$/A8M

Swing: Containers and Components

• !"
• #

$#$%& #

Enter your userid:

Swing: Layout Managers

'() '()*'()* ( ( *+,-" #'()*./012/34 #'()*./012/34 )5# 6 )% )7 6 )%5 8 '()*9: 15;5;)

Swing: Events

6 , 4 , , 4< =6 *+, =< :6> +6-" ? :6> +6-" ? @)-" A A

But this extending a class to add custom behaviors, right?

Where is the boundary?

• MouseAdapter

AWT Framework Swing

• JPanel

JButton $1

Swing Framework Our Implementation

MyWidget

Swing: Custom Components (Reuse)

,9)< ,9)6< '() '()*'()* B

• #

A =66< ) A A

Swing: Custom Components

,9)*< ,9)6< ) A 6#=8) 6#=8) =*6')< 6 @6):8 )** )055)9 ).) A A

OO Frameworks (credit: Erich Gamma)

• &'

'

• !
• 3

framework application

• %
• '
• $!

'

class library

reusing a framework

Framework Challenges (credit: Erich Gamma)

• !
• !'
• )! 3.
• '

) !" . *

• 0! !#M

Framework Layering (credit: Erich Gamma)

• Defaults/Standard Package
• reuse of design and code

Framework Package

• reuse of design
• stable

→ no implementation

• specifies public interfaces

more con more sta

F

StandardDrawing

• LineConnection
• reuse of design and code
• less stable

→ more implementation

• specifies protected interfaces

Kit Packages

• reuse of implementation
• least stable

→ implementation only

re concrete re stable

Evolution: Extract Interface from Class

(credit: Erich Gamma)

⇒B(*!

• #' '

S D>>EB

• M

JHotDraw: Design Patterns Summary

(credit: Erich Gamma)

• J

D>>EB

• !"

• #$
• %
• #$ &!

JHotDraw: Design Patterns Summary

(credit: Erich Gamma)

E D>>EB

• !"

• #$
• %
• #$ &!
• %'

JHotDraw: Design Patterns Summary

(credit: Erich Gamma)

L> D>>EB

• !"

%'

• '

• #$
• %
• #$ &!
• %'

$( $ %(

JHotDraw: Design Patterns Summary

(credit: Erich Gamma)

L D>>EB

• !"

%'

• '
• '

!"'

• $(

$ %(

• #$
• %
• #$ &!
• %'

$( $ %(

JHotDraw: Design Patterns Summary

(credit: Erich Gamma)

L D>>EB

• !"

%'

• '
• '

!"'

• $(

$ %(

• )

• #$
• %
• #$ &!
• %'

$( $ %(

JHotDraw: Design Patterns Summary

(credit: Erich Gamma)

LL D>>EB

• !"

%'

• '
• '

!"'

• $(

$ %(

• )

* *

• #$
• %
• #$ &!
• %'

$( $ %(

• $

$%

JHotDraw: Design Patterns Summary

(credit: Erich Gamma)

L D>>EB

• !"

%'

• '
• '

!"'

• $(

$ %(

• )

* *

• #$
• %
• #$ &!
• %'

$( $ %(

• $

$%

• &$

JHotDraw: Design Patterns Summary

(credit: Erich Gamma)

L D>>EB

• !"

%'

• '
• '

!"'

• $(

$ %(

• )

* * &$

• #$
• %
• #$ &!
• %'

$( $ %(

• $

$%

• &$

JHotDraw: Design Patterns Summary

(credit: Erich Gamma)

LF D>>EB

• !"

%'

• '
• '

!"'

• $(

$ %(

• )

* * &$

• $'

• #$
• %
• #$ &!
• %'

$( $ %(

• $

$%

• &$

JHotDraw: Design Patterns Summary

(credit: Erich Gamma)

LS D>>EB

• !"

%'

• '
• '

!"'

• $(

$ %(

• )

* * &$

• $'

+! +! "

JHotDraw Pattern Experiences

(credit: Erich Gamma)

• /'
• '
• /+
• '
• !'M
• $!

LJ D>>EB

• $!
• '''
• B *
• 3 6%
• 6%
• B(*AA'-A3A3

Getting up a framework’s learning curve

• "'!
• "0=&01#
• $'0C'
• T
• 1-'
• C!'
• =!0A'
• !$
• #T

).

• Library

Framework

$! LE

• D>>EB

).

• /
• /507
• "'0!
• /'
• N+
• T !3!
• *'T )!.
• $!'+# -

Framework Design Exercises

• "!!
• 4'
• 4'0'0'
• '
• /''
• @'
• @'
• ;
• = A#<
• =<
• =<
• (!<

Bonus slides on Frameworks

• >'!

Callback challenges

• -?1"'
• * '
• (
• 1
• 1
• 1*6
• *=B
• >'!
• @#
• =<
• =/<
• =!

#<

• *=B
• *6
• :=:*6
• *

Dynamically add a control to the page

private void Page_Load(object sender, EventArgs e) { DropDownList ddl = new DropDownList(); ddl.DataSource = H; //accesses another control ddl.DataBind(); addControl(ddl); }

=M% 0 +-

Dynamically add a control to the page, attempt 2

private void Page_Load(object sender, EventArgs e) { if (!IsPostBack()) { DropDownList ddl = new DropDownList(); ddl.DataSource = H; //accesses another control ddl.DataBind(); addControl(ddl); } }

8!0 '5!7O-

Dynamically add a control to the page, attempt 3

private void Page_Load(object sender, EventArgs e) { DropDownList ddl = new DropDownList(); if (!IsPostBack()) { ddl.DataSource = H; ddl.DataBind(); } addControl(ddl); addControl(ddl); }

8!00+ AO-

Dynamically add a control to the page, attempt 4

private void Page_PreInit(object sender, EventArgs e) { DropDownList ddl = new DropDownList(); if (!IsPostBack()) { ddl.DataSource = H; //accesses another control ddl.DataBind(); } addControl(ddl); addControl(ddl); }

?'# '+O

Dynamically add a control to the page, attempt 5

DropDownList ddl; private void Page_PreInit(object sender, EventArgs e) { ddl = new DropDownList(); addControl(ddl); } private void Page_Load(object sender, EventArgs e) { private void Page_Load(object sender, EventArgs e) { if (!IsPostBack()) { ddl.DataSource = H; //accesses another control ddl.DataBind(); } }

$!M

Couldn’t they design it better?

• !
• N!#
• /0'

'

• N'
• N'
• ' +
• N'20!

Interaction is not limited to your primary code!

• @'!
• * 0G@
• /0/

<

• '<

Choosing an interaction

• 1#/&
• <
• 1#"
• G@00<
• 1#L*6%
• 1#L*6%
• G@000<
• ?

0'0 'M

Putting controls in a LoginView

''

• 1# -)=0

6M.

<asp:LoginView ID=“LoginScreen” runat=“server”> <AnonymousTemplate> <AnonymousTemplate> You can only setup accounts when you are logged in. </AnonymousTemplate> <LoggedInTemplate> <h4>Location</h4> <asp:DropDownList ID=“LocationList” runat=“server”/> <asp:Button ID=“ChangeButton” runat=“server” Text=“Change”/> </LoggedInTemplate> </asp:LoginView>

Retrieve controls and set them up

LoginView LoginScreen; private void Page_Load(object sender, EventArgs e) { DropDownList list = (DropDownList) LoginScreen.FindControl(“LocationList”); list.DataSource = H; list.DataSource = H; list.DataBind(); }

?%1#-*:O,

Correct code

LoginView LoginScreen; private void Page_Load(object sender, EventArgs e) { if (this.getRequest().IsAuthenticated()) { DropDownList list = (DropDownList) LoginScreen.FindControl(“LocationList”); list.DataSource = H; list.DataBind(); list.DataBind(); } }

These sound tough to useHwhy bother?

• 1!U0>>>0>>>
• 1'
• O!
• @
• 1#'!'
• 1#
• '57
• N2

Frameworks and Quality Attributes

• ;
• V
• ;+
• 8!2
• ?12!
• @ 0'
• (' 0'
• =!!;
• "2O

Choosing a framework

• N3
• 1#'!
• 2
• '
• '
• 5

'7

Do we build it ourselves?

• 8'!
• 1#10B110-?0
• N!0'0
• A!
• /'!
• /'!
• 1#!
• N0
• A!'02#