Web Application Maker a declarative web database tool

Web Application Maker: a declarative web database tool Miguel Calejo, Mário Araújo, Sónia Mota Araújo, Nuno Soares, Rui Marante Declarativa, Portugal http: //www. declarativa. com DM-UA, 24 -10 -2003 Copyright Declarativa 2003 1

http: //www. declarativa. com Declarativa, 24 -Oct-2003 • 31/2 years, 5 engineers, tools • Two areas of declarative development – Inter. Prolog: Java JFC/Swing + Prolog – WAM: browser+Active Server Pages+SQL Server • Contracts with XSB Inc. /Do. D (USA); ME, CVRVV, CRAT, Servisoft (Portugal) DM-UA, 24 -10 -2003 Copyright Declarativa 2003 2

http: //www. declarativa. com More about Declarativa • Microsoft Certified Partner. . . –. . . with a grain of salt • Incubated at Servisoft – – Early Web Information System adopter Administrative support Internet Building DM-UA, 24 -10 -2003 Copyright Declarativa 2003 3

http: //www. declarativa. com WAM projects: Do. D/XSB, Inc. DM-UA, 24 -10 -2003 Copyright Declarativa 2003 4

http: //www. declarativa. com WAM projects: CVRVV DM-UA, 24 -10 -2003 Copyright Declarativa 2003 5

http: //www. declarativa. com WAM projects: Servisoft DM-UA, 24 -10 -2003 Copyright Declarativa 2003 6

http: //www. declarativa. com Spaghetti code in the internet era DM-UA, 24 -10 -2003 Copyright Declarativa 2003 7

http: //www. declarativa. com More declarative scenario DM-UA, 24 -10 -2003 Copyright Declarativa 2003 8

http: //www. declarativa. com Enter: declarative web development • Web Application Maker (WAM) – – Model-driven, based on SQL Server Given a DB schema with triggers, constraints, etc. . . get web interface with user profiles, etc. Flexible: GUI generators exposed to the developer • Follow any software engineering method, . . –. . . and use the resulting database • Part of Declarativa’s Web Information Systems Toolkit DM-UA, 24 -10 -2003 Copyright Declarativa 2003 9

http: //www. declarativa. com The WAM picture DM-UA, 24 -10 -2003 Copyright Declarativa 2003 10

http: //www. declarativa. com WAM “Equations” • Web interface = WAM(DB Meta Information + WAMmodel) + Custom. ASP pages using WAM objects + other pages • Default web interface = WAM(DB Meta Inf. + Default WAMmodel) • An acceptable interface working sooner is better than a fancy one later! DM-UA, 24 -10 -2003 Copyright Declarativa 2003 11

http: //www. declarativa. com WAMmodel • Information added to the database schema to allow reasonable GUI generation – – WAM_PRESENTATION WAM_LIST, WAM_LIST_COLUMN WAM_LOOKUP_COLUMN WAM_PROCEDURE_CALL • 10 tables total DM-UA, 24 -10 -2003 Copyright Declarativa 2003 12

http: //www. declarativa. com WAM: a web GUI fragment factory • Entry page • (Regular) Lists, List columns • Detail lists – Stand-alone – Embbeded • Search Criteria • Rows, Row fields, Lookup fields • Context path, procedure callers, error reporting DM-UA, 24 -10 -2003 Copyright Declarativa 2003 13

http: //www. declarativa. com Fragment example: lookups DM-UA, 24 -10 -2003 Copyright Declarativa 2003 14

http: //www. declarativa. com Demo – “Northwind” database DM-UA, 24 -10 -2003 Copyright Declarativa 2003 15

http: //www. declarativa. com Entry page A default entry page, with all lists plus direct navigation to “interesting” tables Uses WAM_TABLE_GROUP DM-UA, 24 -10 -2003 Copyright Declarativa 2003 16

http: //www. declarativa. com A user-configurable list Automatic joins, both detail master and master detail DM-UA, 24 -10 -2003 Copyright Declarativa 2003 17

http: //www. declarativa. com Row with embedded list and 3 LKs DM-UA, 24 -10 -2003 Copyright Declarativa 2003 18

http: //www. declarativa. com Relational navigation extreme DM-UA, 24 -10 -2003 Copyright Declarativa 2003 19

http: //www. declarativa. com Editing the WAMmodel • SQL client tools, or. . . • WAMAdmin – – A WAM application Standard lists and rows for all WAMmodel tables Some utilities Complemented by runtime “edition mode”, adequate for administrators/power users – Try it at http: //showroom. declarativa. com DM-UA, 24 -10 -2003 Copyright Declarativa 2003 20

http: //www. declarativa. com WAMAdmin DM-UA, 24 -10 -2003 Copyright Declarativa 2003 21

http: //www. declarativa. com Editing the WAMmodel for a row DM-UA, 24 -10 -2003 Copyright Declarativa 2003 22

http: //www. declarativa. com Editing a WAMmodel tuple DM-UA, 24 -10 -2003 Copyright Declarativa 2003 23

http: //www. declarativa. com Back to the WAM equations • So far we’ve seen. . . • Web interface = WAM(DB Meta Information + WAMmodel) + Custom ASP pages using WAM objects + other pages • Default web interface = WAM(DB Meta Inf. + Default WAMmodel) DM-UA, 24 -10 -2003 Copyright Declarativa 2003 24

http: //www. declarativa. com Customized ASPs: WAM API DM-UA, 24 -10 -2003 Copyright Declarativa 2003 25

http: //www. declarativa. com An ASP invoked from a WAM list DM-UA, 24 -10 -2003 Copyright Declarativa 2003 26

http: //www. declarativa. com Beyond WAM – WIS Toolkit • Making Web Information Systems real • The WIS Tookit contains WAM plus. . . – – – “Calibrated” HTML printing Automatic email/fax communications Template-based document generator Automatic URL validation Extraction of structured data from (HTML) organizational knowledge documents DM-UA, 24 -10 -2003 Copyright Declarativa 2003 27

http: //www. declarativa. com Web Information Systems Toolkit DM-UA, 24 -10 -2003 Copyright Declarativa 2003 28

http: //www. declarativa. com WAM - Near Future • Upcoming features – External documents/workflow • Glean link structure, extended navigation – Pocket. PC (with WAM’s WAP interface) – Full historical data, with interface – More data type-dependent formatting • FLUX – “Fle. Xible Logical Updates” project – “establish a flexible declarative language for the specification of dynamic knowledge, and to apply it to realistic application domains” – Universidade Nova de Lisboa + Declarativa – WAMmodel manipulation in Prolog DM-UA, 24 -10 -2003 Copyright Declarativa 2003 29

http: //www. declarativa. com Initial FLUX experiments(1) • WAMmodel export/import utility (SQL/XSBProlog) – WAMmodel tables & views Prolog relations • “Embedding detail lists that belong to aggregations” : - foreign. Key(FK, Detail, Master, DColumns, MColumns), table(Detail, _, BT), table. Index(BT, PKcols, primary. Key), column. Subset(DColumns, PKcols), !, retractall(lookup. Column(FK, _, _, _)). column. Subset([], _) : - !. column. Subset([FKC-_|FKcols], PKcols) : - member(FKC-_, PKcols), column. Subset(FKcols, PKcols). DM-UA, 24 -10 -2003 Copyright Declarativa 2003 30

http: //www. declarativa. com Initial FLUX experiments(2) • “Disable interface for columns changed by server code” : - uses(Type, _, table, Table, Column, update), (Type=procedure; Type=trigger), assert(row. Column(Table, Column, 0, 1, 0)), fail. • “Creating stored procedure calls” : - procedure(P, Args), not uses(_, _, procedure, P, _), table(T, Columns, BT), table. Index(BT, PKcols, primary), compatible. Args(Args, PKcols, Columns), assert(procedure. Call(T, row, P, 1, 0)), fail. compatible. Args(. . . ). -. . . DM-UA, 24 -10 -2003 Copyright Declarativa 2003 31

http: //www. declarativa. com Conclusion • How to reproduce the Demo • Pushing focus to the database layer – The Declarativa project distortion field • Statistics – Simple effort metrics • Prospects for academic R&D – Make your models run • How to build a tool in the “real world” – On adult supervision, genes and memes DM-UA, 24 -10 -2003 Copyright Declarativa 2003 32