Seaside Web Application Toolkit for Squeak

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1 Web Application Toolkit for Squeak Sheet #1

2 Introduction About us Lukas Renggli Adrian Lienhard users of the framework Developers Avi Bryant Julian Fitzell Sheet #2

3 Content What can be done with? Example Application: SWebMail Reading mailbox form POP account Sending s over SMTP server Why should be used? Complete separation of logic and design Object-oriented programming on the fly Application control flow Why is so easy to use? Action methods Bidirectional binding of properties Session management Sheet #3

4 Component-Template Model SWebMail Server () SWebMailInbox SWebMailMain... IAComponent +html()... SWebMail +html() SWebMailMain +html() SWebMailInbox +html() Client (Web Browser) Sheet #4

5 Reuse by Composition Component architecture Widgets Tab sheet Date selector Batches Sortable tables Dialogs Information Confirmation Choose Ask Sheet #5

6 Separation of Logic and Design Programmers should create logic Designers should create HTML (templates) M V C IAComponent Model ViewController +html() +actionmethod() Sheet #6

7 Creation of Templates Override IAComponent>>html and return a string containing valid HTML SWebMail>>html ^ '<html> <head> <title>swebmail</title> <style type="text/css">[css]</style> </head> <body> <h1>swebmail</h1> <swebmaillogin sea:id="login"></swebmaillogin> </body> </html>' V External files WYSIWYG editors Designers can work independently Sheet #7

8 Binding of Properties Unidirectional binding SWebMailView>>html ^ '... <tr> <td>subject:</td> <td>[message.subject]</td> </tr>...' Bidirectional binding SWebMailCompose>>html ^ '... <form sea:id="reload"> <input type="text" sea:id="subject">...' SWebMailCompose>>subject ^ subject ifnil: [ subject := String new ] SWebMailCompose>>subject: astring subject := astring V V C Sheet #8

9 Template-Variable Look Up Looking up sequence of properties Template Locals Accessor methods Instance variables SWebMailInbox>>html ^ '... <tr sea:id="item/sortedmessages"> <td>[item.subject]</td> <td>[item.fromaddress]</td>...' V Sheet #9

10 Action Methods Modify the component's state Message is executed Same component is redisplayed The action method might also Expect a parameter Replace the current component at runtime Throw an exception: a stack-dump will be sent to the browser SWebMailMain>>html ^ '... <a href="@about">about</a>...' SWebMailMain>>about self callpage: (SWebMailAbout new) V C Sheet #10

11 Application Control Flow Common way Manual stack handling Difficult to implement Error prone 1: goto 2: goto 3: goto Login Inbox View Reply Transforms traditional Smalltalk send/return control flow onto the web Supports Backtracking (back button) Transactions (full blocks) Sheet #11

12 Application Control Flow Call pages with message: IAComponent>>callPage: acomponent Return result from page with message: IAComponent>>return: avalue 4: #callpage: Reply 3: #callpage: View 5: #return 1: #callpage: Login Inbox 2: #return: 8: #return: 6: #return 7: #confirm: Dialog C Sheet #12

13 Session Management manages and caches all needed session data automatically Each session has its own set of objects Caches: LRU, Expiring,... Example: IASession is subclassed to Store the user-preferences Login and logout handling IASession SWebMailSession SWebMailPreferences Sheet #13

14 Goodies Web-based inspector Profiler Configuration tools Sheet #14

15 2.0 (Borges) Full reimplementation Supports a wider set of styles Layered design Borges-Components Control flow between pages Safe backtracking Component embedding Borges-Support Callback system HTML renderer Borges-Kernel HTTP session Request Response Sheet #15

16 Comparison Language OOP Reuse Separation Control Flow Debugging Database Large Systems Integration Smalltalk Complete Heavily Yes Message calling WebInspector (Seashell), GOODS, Tantalus, ODBC,... Not tested Apache Zope Python Partly Possible No, but ZPT Request, Response Difficult ZODB, PostgreSQL, MySQL, ODBC,... Possible Apache Sheet #16

17 Summary : Squeak Enterprise Aubergines Server Developers: Avi Bryant, Julian Fitzell Current Version: License: Squeak-L, BSD Works best with Squeak 3.0, 3.1, 3.2 Comanche 4.9, 4.10 Windows, Mac OS X, Linux, SUN Unix,... Ports underway Dolphin Smalltalk VisualWorks Sheet #17

18 References Homepage (Borges) Documentation Download SWebMail Homepage Running Server Sheet #18

Lukas Renggli Lukas Renggli, August 2003 Slide 1

Smalltalk Wiki towards CMS Lukas Renggli Lukas Renggli, August 2003 Slide 1 Why another Wiki? ß Object Oriented Design ß Extensibility ß Components ß Web server ß Storage ß Open source ß Dialect independent