Squeak at NetStyle Adrian Lienhard & Lukas Renggli, (ESUG 2003, Bled)

1. Roadmap
ß Introduction
ß Seaside Web Applications
ß Example: Insurance Application
ß Server Management Interface
ß ROE
ß Smalltalk Relational DB Access
Adrian Lienhard & Lukas Renggli, August 2003 Slide 1

2. Introduction
ß netstyle.ch founded in 2000
ß Startup specialized in developing
Web-Applications
ß Team of ~6 people (most parttime)
Adrian Lienhard & Lukas Renggli, August 2003 Slide 2

3. Seaside Web-Application
ß Sophisticated framework in Squeak
ß Server setup:
Component Component
Seaside
Comanche / Swazoo
Static files
Apache
http(s)
Web-client
Adrian Lienhard & Lukas Renggli, August 2003 Slide 3

4. Example
ß Domain: Health Insurance
ß Specialized little company with
agencies
ß Application: Extranet for...
ß creating and manageing offers (with
printing/pdf)
ß process of accepting new policies
ß management of existing customers with
document-management
ß billing for agencies
Adrian Lienhard & Lukas Renggli, August 2003 Slide 4

5. Screenshots
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10. ROE
ß Generic DB access using Smalltalk
ß Automatically generated SQL
ß Implementation by Avi Bryant
ß Extended while developing insurance
application
Adrian Lienhard & Lukas Renggli, August 2003 Slide 10

11. Example: Create Table
person := factory relation: ‘person’.
person
create;
addColumn: #id withType: #int;
addColumn: #name withType : #text.
CREATE TABLE person ();
ALTER TABLE person ADD COLUMN “id” INT;
ALTER TABLE person ADD COLUMN “name” TEXT;
Adrian Lienhard & Lukas Renggli, August 2003 Slide 11

12. Simple Example
query := person where: [ :id :name |
id > 200 & (name like: ‘avi%’) ].
query := query project: #id.
query do: [ :row |
…]
SELECT "id" FROM
(SELECT * FROM (SELECT * FROM person)
WHERE ("id">200) AND ("name" LIKE 'avi%'))
Adrian Lienhard & Lukas Renggli, August 2003 Slide 12

13. Class Diagram
Collection
1 1
Relation
Transform
1 2
Unary Binary
Project Join
Concrete Select Intersect
Alias Difference
Array Postgres Order Union
Distinct
…
Adrian Lienhard & Lukas Renggli, August 2003 Slide 13

14. Advanced Example
relation := PLPerson relation where: [ :lastname |
lastname like: ‘%’ , self searchName , ‘%’ ignoreCase: true ].
relation := relation project: #familyid.
relation := relation * PLPersistentVersionHolder relation.
relation := relation whereEqual: #(versionid familyid).
relation := relation project: #holderid.
relation := relation * PLInternetOffer relation.
relation := relation whereEqual: #(holderid id).
relation := self applyVisibilityRules: relation.
relation := relation project: #id.
relation := relation distinct.
Adrian Lienhard & Lukas Renggli, August 2003 Slide 14

15. Algebraic Representation
P[id](S[(holderid=id)](P[holderid]
(S[(versionid=familyid)](P[familyid]
(S[(lastnameilike'%avi%')]
(table_person)) X
table_version_holder)) X
table_internetoffer))
Adrian Lienhard & Lukas Renggli, August 2003 Slide 15

16. SQL Query
SELECT DISTINCT * FROM
(SELECT "id" FROM (SELECT * FROM
(SELECT * FROM (SELECT "holderid" FROM
(SELECT * FROM (SELECT * FROM (SELECT
"familyid" FROM (SELECT * FROM (SELECT
* FROM table_person) WHERE ("lastname"
ILIKE '%avi%'))), (SELECT * FROM
table_version_holder)) WHERE
("versionid"="familyid"))), (SELECT * FROM
table_internetoffer)) WHERE
("holderid"="id")))
Adrian Lienhard & Lukas Renggli, August 2003 Slide 16

17. Transaction Example
factory transaction: [
users add: #(id name) values: #(1 avi).
users add: #(id name) values: #(2 adi).
“other updates, queries, …” ]
BEGIN;
INSERT INTO users (id, name) VALUES (1, ‘avi’);
INSERT INTO users (id, name) VALUES (2, ‘adi);
…
ROLLBACK;
COMMIT;
Adrian Lienhard & Lukas Renggli, August 2003 Slide 17