Structured Documents KA1 Document Type definition DTD.

Structured Documents KA 1

Document Type definition

DTD


Structural Analysis Structural Analysis and DTDand DTD1. Structural Analyses and DTD

2. What is DTD

3. Ex: phonebook.dtd

4. Ex: phonebook.xml

5. Parts of XML Document

6. Producing XML Document

7. XML Browsers

8. Ex phonebook.xsl

9. DTD Planning

10. XML: Separators

11. XML: Comments and Naming

12. XML: Elelemnts

13. XML: Order of elements

14. Ex: Letter

15. Ex: Letter b

16. Ex: letter c

17. DTD: Building Blocks

18. DTD: Elements

19. XML tags

20. DTD: Attributes

21. Types of Attribute

22. Attribute Defaults

23. DTD: Predefined Entities

24. DTD: Own Entities

25. DTD: PCDATA / CDATA


What is a DTDWhat is a DTD

• DTD = Document Type Definition

definition of the document class

•DTD descripes the logical elements, their order and content

•DTD can be created from the structure diagram

Example phonebook.dtdExample phonebook.dtd<!ELEMENT phonebook (person*)><!ATTLIST phonebook company CDATA #REQUIRED><!ELEMENT person (firstname, surname,address,phone )><!ELEMENT address (street,postalcode, postoffice)><!ELEMENT phone (homenumber, mobile)><!ATTLIST phone confidential (yes | no ) "no"><!ELEMENT firstname (#PCDATA)><!ELEMENT surname (#PCDATA)><!ELEMENT street (#PCDATA)><!ELEMENT postalcode (#PCDATA)><!ELEMENT postoffice (#PCDATA)><!ELEMENT homenumber (#PCDATA)><!ELEMENT mobile (#PCDATA)>

Example phonebook. xmlExample phonebook. xml<?xml version="1.0" encoding="ISO-8859-1"?><?xml-stylesheet type="text/xsl" href="phonebook.xsl"?><!DOCTYPE phonebook SYSTEM "phonebook.dtd">

<phonebook company = "Gurus ltd"><person>

<firstname>Michael</firstname><surname>Schumacher</surname><address>

<street>Nelikkoratsu 2 A56</street><postalcode>01234</postalcode><postoffice>Heinola</postoffice>

</address><phone> <homenumber>04 11223 344</homenumber>

……


Parts of an XML Parts of an XML DocumentDocumentA XML document itself consist of:

• XML declaration (can be missing)

• Document Type Definition (DTD can be missing)

• Root element (eg. <mail>

• Document instance (representative of the document class)

XML declaration informs the XML prosessing system about the version and the character set e.g.

DTD can be written directly into a document itself or into another document


Producing an XML Producing an XML DocumentDocument

XML +

DTD

XML editor

dbase dbase

simple editor

Paperdoc

IntelligentIntelligent

OCROCRStructureddoc

conversionconversion

• XML Spy

• XMetal

• Eclipse


Example phonebook.xslExample phonebook.xsl<?xml version="1.0" encoding="ISO-8859-1"?><xsl:stylesheet version="1.0”

xmlns:xsl="http://www.w3.org/1999/XSL/Transform"><xsl:template match="/"> <html> <body> <h1>Phonebook</h1> <h2>Company <xsl:value-of select="@company"> </h2> <h4> …..


DTD PlanningDTD Planning1. Define application area (firm, department …)2. Define strategy of using the DTD

1. Why to do the DTD?2. How DTD is applied?3. Priority of functionality?4. Access criterias?5. Sorting/Calculation criterias

3. Define the users4. Name the DTD5. Define the logical elements of the document class

1. Structure analyzes2. Name the elements3. Element vs. attribute


XML: SeparatosXML: Separatos

<! < </ > /> Used to separate the information and the

markup E.g. <h1> Header</h1>


XML: Comments and XML: Comments and NamingNaming A comment is defined <! - - This is a comment - - > XML name consist of the following chars: 1. char a-z, A-Z 2-n. char a-z, A-Z, 0-9,.,- NO tab or whitespace XML names are CASE sensitive


XML: ElementsXML: Elements Element format <to> Element ending </to> Element is defined in the DTD

<!ELEMENT to (#PCDATA) > Element can include other elements

<!ELEMENT letter (to, from, p*)> The part within the parenthis is called the model

group. Element can be text, #PCDATA or include other

elements.


XML: Order of ElementsXML: Order of Elements

Elements in sequence are separated with a comma (,)

0,1 or n times appearing elements with (*) 1 or n times appearing elements with (+) Alternative elements with a pipe (|) 0 or 1 time appearing element with a question

mark (?)


Example: letterExample: letterletter.dtd

<!ELEMENT letter (from, to, p*, sign)>

<!ELEMENT from (#PCDATA) >

<!ELEMENT to (#PCDATA) >

<!ELEMENT p (#PCDATA) >

<!ELEMENT sign (#PCDATA) >

letter.xml

<?xml version=“1.0”?>

<!DOCTYPE letter SYSTEM ”letter.dtd">

<letter>

<from>Seija R.</from>

<to>Kake A.</to>

<p>Perjantaina on tiimipalaveri</p>

<sign>Seija R.</sign>

</letter>


Example: letter bExample: letter bletterb.dtd<!ELEMENT LETTER (HEADER, BODY, END)><!ELEMENT HEADER (TO, FROM, SUBJECT)><!ELEMENT BODY (P*) ><!ELEMENT END (SIGN*) ><!ELEMENT FROM (#PCDATA) ><!ELEMENT TO (#PCDATA) ><!ELEMENT SUBJECT (#PCDATA) ><!ELEMENT P (#PCDATA) ><!ELEMENT SIGN (#PCDATA) >

letterb.xml

<?xml version=“1.0”?>

<!DOCTYPE LETTER SYSTEM ”letterb.dtd">

<LETTER><HEADER>

<FROM>Seija R.</FROM>

<TO>Kake A.</TO>

<SUBJECT>Tiimipalaveri</SUBJECT>

</HEADER>

<BODY>

<P>Perjantaina on tiimipalaveri</P> </BODY>

<END> <SIGN>Seija R.</SIGN>

<SIGN>Erkki R.</SIGN> </END>

</LETTER>


Example: letter cExample: letter c

letterc.dtd

<!ELEMENT LETTER (HEADER, BODY, END)>

<!ELEMENT HEADER (((FROM,TO+) | (TO+, FROM)), SUBJECT)>

<!ELEMENT BODY (P*) >

<!ELEMENT END (SIGN*) >

<!ELEMENT FROM (#PCDATA) >

<!ELEMENT TO (#PCDATA) >

<!ELEMENT SUBJECT (#PCDATA) >

<!ELEMENT P (#PCDATA) >

<!ELEMENT SIGN (#PCDATA) >


DTD Building BlocksDTD Building Blocks

Seen from a DTD point of view, all XML documents (and HTML documents) are made up by the following simple building blocks: Elements Tags Attributes Entities PCDATA = parseable character data CDATA


DTD: ElementsDTD: Elements

Elements are the main building blocks of both XML and XHTML documents.

Examples of XHTML elements are "body" and "table". Examples of XML elements could be "note" and "message".

Elements can contain text, other elements, or be empty. Examples of empty HTML elements are "hr", "br" and "img".


XML: TagsXML: Tags

Tags are used to markup elements.A starting tag like <element_name> marks

up the beginning of an element, and an ending tag like </element_name> marks up the end of an element.

body element marked up with body tags: <body>body text in between</body>.

message element marked up with message tags: <message>some message in between</message>


DTD: AttributesDTD: AttributesAttributes provide extra information about elements.Attributes are always placed inside the starting tag of an

element. Attributes always come in name/value pairs. The following "img" element has additional information about a source file:

<img src="computer.gif" />The name of the element is "img". The name of the attribute

is "src". The value of the attribute is "computer.gif". Since the element itself is empty it is closed by a " /".

DTD: <!ATTLIST DRINK amount CDATA>

.xml: <DRINK amount=”4 dl">


Types of AttributeTypes of AttributeType Meaning

CDATA Character data (string)

IDIDREFIDREFS

Name unique within a given documentReference to some element bearing an ID attribute

Series of IDREFs delimited with white spaceENTITYENTITIES

Name of predefined external entitySeries of entity names delimited by white space

NMTOKEN A name

NOTATION Accepts one of a series of explicitly user-defined values that the attribute can take on

dtd: <!ATTLIST someEl someText CDATA #IMPLIED>

xml:< someEl someText =”Pisa is something”>

dtd: <!ATTLIST Person ssn ID #REQUIRED>

xml:< Person ssn = ”22-11-20033”> … </Person>


Attribute DefaultsAttribute Defaults

Value Explanation

value The attributes default value

#DEFAULT value The attributes default value

#REQUIRED The attribute value must be included in the element

#IMPLIED The attribute does not have to be included

#FIXED value The attribute value is fixed

<!ATTLIST catalog music (pop | classic | unqualified ) #REQUIRED>


DTD: Predefined EntitiesDTD: Predefined Entities

Entities are variables used to define common text. Entity references are references to entities.

Most of you will know the HTML entity reference: " ". This "no-breaking-space" entity is used in HTML to insert an extra space in a document. Entities are expanded when a document is parsed by an XML parser.

The following entities are predefined in XML:

Entity References Character< <> >& &" "' '


DTD: Own EntitiesDTD: Own Entities<!ENTITY EVTEK ”Espoo Vantaa Instituite of

Technology">

<!ENTITY deg ”°”>

Every where in XML file the note

&EVTEK;

is replaced with string

Espoo Vantaa Instituite of Technology

and<joke>It is 45 ° now in Turkey </joke>

is replaced with string

It is 45° now in Turkey


DTD: PCDATA / CDATADTD: PCDATA / CDATA

PCDATA means parsed character data.

PCDATA is text that will be parsed by a parser. Tags inside the text will be treated as markup and entities will be expanded.

CDATA also means character data.

CDATA is text that will NOT be parsed by a parser.

Tags inside the text will NOT be treated as markup Tags inside the text will NOT be treated as markup and entities will not be expanded.and entities will not be expanded.

Structured Documents KA1 Document Type definition DTD.

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