Overcoming the limitation of XML Documentation Type Definition

Overcoming the limitation of XML Documentation Type Definition XML schema generator CS 689 Hae-Soon Kwon 11/16/2000

Content 1. Research Problem 2. Research Goal 3. Literature Review 4. Significance of the Study 5. Research Design 6. Data Analysis 7. Schedule 8. Facilities and Resources 9. Deliverables

Research Problem n Extensible Markup Language(XML): developed by W 3 C to replace the conventional web languages. n XML documents originate well-formed ness and validation. n If the Document Type Definition file(DTD) is declared for that XML document then we can say it is valid. n DTD is a grammar to use the free parsers in that XML document.

Research Problem n (continue) Several weaknesses of XML DTD: - Difficulty of implementation - Not guarantee of validation for the document - No supporting by regular language grammar n To overcome the weaknesses: - W 3 C released XML Schema ( October 2000) - There are several researches and tools to generate DTD automatically but they have their own limitations. - New effort is required to provide a method for generating XML Schema.

Research Goal n To make an automatic XML Schema generator n To make valid XML document n To provide the convenience way to the XML users to create XML Schema

XML Schema-compared with DTD n XML Schema has prefix ‘xsd: ’ associated with its type( ex) <xsd: element> </xsd: element> ) n XML distinguishes element type to element, complex. Type and simple. Type and so on n Element value type is explained in more specific way (ex) <xsd: element name=“age” value=“xsd: integer”/> ) n For more information: W 3 C Schema Recommendation( http: //www. w 3. org/TR /xmlschema)

Basic technical term n XML document <person> <name> <first name> Chris </first name> <last name> Allen </last name> </name> <age> 25 </age> <gender> male </gender> </person> Next: XML DTD

Basic technical term n XML DTD <!ELEMENT <!ELEMENT Next: XML Schema person ( name, age, gender )> name ( first_name, last_name)> first_name (#PCDATA)> last_name (#PCDATA)> age (#PCDATA)> gender (#PCDATA)>

Basic technical term n XML Schema <xsd: schema xmlns: xsd=”http: //www. w 3. org/1999/XMLSchema”> <xsd: element name=”person” type=”person”/> <xsd: complex. Type name=”person”> <xsd: element name=”name” type=”name”/> <xsd: complex. Type name=”name”> <xsd: element name=”first_name” type =”xsd: string”/> <xsd: elementname=”last_name” type=”xsd: string”/> </xsd: complex. Type> <xsd: element name=”age” type=”xsd: integer”/> <xsd: element name=”gender”type=”xsd: string”/> </xsd: complex. Type>

Literature Review n DTD-Miner (Chung-Hue Moh, et al. 2000): automatic DTD generator n Using Regular Tree Automata as XML Schema ( Boris Chidlovskii, 2000): give a method to convert tree automata to DTD n DTD Creation from URL or Simple Text( Keith E. Shafer, 1995): give methods to communicate with clients and to handle errors n Using a Custom DTD( Web Design Group, 1999)

Significance of the Study n The study for automatic generating XML Schema is the requirement of current trends and this study may be a cornerstone in this field.

Research Design: Frame Work Browser for user XML document Schema file Schema generator module Schema file Interface module Preprocessor module Web interface Preprocessor module Set of tags Union tree construction module Schema construction module If max repetition # is greater than 1 Document tree Extraction module If max repletion # =1

Research Design: n n implementation To communicate with users: HTML and CGI script To generate trees and Schema: Java

Data Analysis n Schema generator will be tested to measure how correctly it works. n Both URL and text form XML documents will be used for input file. n Each line that is generated by the generator will be compared with original Schema by hand. n Every program implementation step will be tested and feedback.

Schedule Jan Mar May July Algorithm development Web-related programming Schema generator module implementation Test and feedback Oct

Facilities and Resources n Tree automata algorithm n DTD-Miner n Automatic DTD creating tool: Fred n DTD/Schema Editors/Tools n Miscellaneous

Deliverables n Automatic XML Schema generator n Its algorithm

Thank you… Question? Happy Thanksgiving