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BUSS 909 Office Automation & Intranets Lecture 5 From Storage to Interchange: Standard Generalized BUSS 909 Office Automation & Intranets Lecture 5 From Storage to Interchange: Standard Generalized Markup Language (SGML) Clarke, R. J (2001) L 909 -05: 1

Notices 1 n Assignment 1 is due next week n Assignment 2 will be Notices 1 n Assignment 1 is due next week n Assignment 2 will be available from the Intranet next week. As with the current assignment, there are some administrative requirements that must be fulfilled by all studentsdescribed next lecture Clarke, R. J (2001) L 909 -05: 2

Notices (2) n to accommodate the new T 1 tutorial for this subject, my Notices (2) n to accommodate the new T 1 tutorial for this subject, my Consultation Time C 1 which was 14: 30 -16: 30 is now 13: 3015: 30 40. 242 remaining in effect until the end of session Clarke, R. J (2001) L 909 -05: 3

Agenda n Types of Markup n Stylesheets & Markup (wrt HTML) n SGML Standard Agenda n Types of Markup n Stylesheets & Markup (wrt HTML) n SGML Standard n SGML Example n SGML Benefits n Adopting SGML Clarke, R. J (2001) L 909 -05: 4

Types of Markup Clarke, R. J (2001) L 909 -05: 5 Types of Markup Clarke, R. J (2001) L 909 -05: 5

Types of Markup n the following slides show an extract from a Vincent motorcycle Types of Markup n the following slides show an extract from a Vincent motorcycle repair manual to illustrate the types of markup which can be used on a document n but just in case you don’t know what a Vincent motorbike looks like, here is a picture of a 1994 rebuild of the 1959 classic. . . Clarke, R. J (2001) L 909 -05: 6

1994 Vincent Motorcycle Clarke, R. J (2001) L 909 -05: 7 1994 Vincent Motorcycle Clarke, R. J (2001) L 909 -05: 7

Types of Markup Procedural Markup n the following two slides shows an extract from Types of Markup Procedural Markup n the following two slides shows an extract from a Vincent motorcycle repair manual showing the procedural markup n this kind of markup tells a workprocessor or other related system how to render (or display) the page Clarke, R. J (2001) L 909 -05: 8

Procedural Markup Centre; 10 pt Times-Roman Down 10 pt; centre; 12 pt. Helvetica Bold Procedural Markup Centre; 10 pt Times-Roman Down 10 pt; centre; 12 pt. Helvetica Bold Down 15 pt. ; first line indent 0. 3 inch; 12 -pt. Times Roman Down 22 pt. ; centre; 10 -pt. Helvetica Medium Down 5 pt. ; centre; 12 -pt Helvetica Bold Down 10 pt. ; 12 -pt Times Roman run-in bold (Source: Nicholson Brothers Motorcycles Ltd. 1994) Clarke, R. J (2001) L 909 -05: 9

Procedural Markup (continued) Down 22 pt. ; centre; 10 -pt. Helvetica Medium Down 5 Procedural Markup (continued) Down 22 pt. ; centre; 10 -pt. Helvetica Medium Down 5 pt; centre; 12 pt. Helvetica Bold Down 15 pt. ; 12 -pt. Times Roman Down 10 -pt. ; indent 0. 32 inch first line indent 0. 325 inch right align 0. 2 inch; tab left alighed 0. 325 inch 12 -pt. Times Roman (Source: Nicholson Brothers Motorcycles Ltd. 1994) Clarke, R. J (2001) L 909 -05: 10

Types of Markup Descriptive Markup n the following two slides shows an extract from Types of Markup Descriptive Markup n the following two slides shows an extract from a Vincent motorcycle repair manual showing the descriptive markup n the descriptive markup used in this example identifies the structure of the document n this type of markup could be used to describe the data or information structure of the document Clarke, R. J (2001) L 909 -05: 11

Descriptive Markup chapnum (Chapter number) titlepara sectnum(Section Number) title labitem (Label list item) (Source: Descriptive Markup chapnum (Chapter number) titlepara sectnum(Section Number) title labitem (Label list item) (Source: Nicholson Brothers Motorcycles Ltd. 1994) Clarke, R. J (2001) L 909 -05: 12

Descriptive Markup (continued) sectnum (Section number) title sectnum (Section number) listitem (List item) (Source: Descriptive Markup (continued) sectnum (Section number) title sectnum (Section number) listitem (List item) (Source: Nicholson Brothers Motorcycles Ltd. 1994) Clarke, R. J (2001) L 909 -05: 13

Stylesheets and Markup Emphasising HTML Clarke, R. J (2001) L 909 -05: 14 Stylesheets and Markup Emphasising HTML Clarke, R. J (2001) L 909 -05: 14

Stylesheets and Markup n for any real document based system, we need to: n Stylesheets and Markup n for any real document based system, we need to: n design the content of the documentdescriptive markup- independent of its look n design the look of the document- procedural markup- independent of its content n we need to relate them together because content must be displayed- this is done by using stylesheets Clarke, R. J (2001) L 909 -05: 15

Stylesheets and Markup Stylesheet Focus: Assist users/readers in interpreting the meanings of a document Stylesheets and Markup Stylesheet Focus: Assist users/readers in interpreting the meanings of a document by means of a consistent visual look Function: providing a consistent look and feelprocedural issue- to meaningful elements of a document- descriptive issue. Prescriptive Markup Descriptive Markup Focus: Information System Focus: Human Users Function: How to display or render the elements of a document Function: What is the meaning of an element in a document, what purpose does it serve for the organisation Clarke, R. J (2001) L 909 -05: 16

Stylesheets and Markup Hyper Text Markup Language n In principle, HTML as a standard Stylesheets and Markup Hyper Text Markup Language n In principle, HTML as a standard attempts to provide structural meaning to page content- the purpose of tags n what is enclosed between

is interpreted as a paragraph n unfortunately, structural markup is only a limited form of descriptive markup Clarke, R. J (2001) L 909 -05: 17

Stylesheets and Markup HTML 4. 0 Specification (1) n unfortunately, most web page authors Stylesheets and Markup HTML 4. 0 Specification (1) n unfortunately, most web page authors concentrate only on the look of the page (by heavily using the procedural markup oriented tags) n the introduction of the HTML 4. 0 specification attempted to distance the content of web pages from formatting issues Clarke, R. J (2001) L 909 -05: 18

Stylesheets and Markup HTML 4. 0 Specification (2) n this standard encouraged reduction in Stylesheets and Markup HTML 4. 0 Specification (2) n this standard encouraged reduction in the use of formatting (procedural) markup like and . . . , . . . etc. tags n formatting was assigned to a separate standardization effort related to content style- Cascading Style Sheet (CSS) n provided the means to pass the decision as to how a paragraph looks to a style definition Clarke, R. J (2001) L 909 -05: 19

Stylesheets and Markup Link between Stylesheet and Content n In HTML, the link between Stylesheets and Markup Link between Stylesheet and Content n In HTML, the link between a style sheet and the content it influences is either: n tag name of the HTML element that holds the content or, n an identifier associated with the element by way of an attribute (eg. ID or a CLASS attribute) Clarke, R. J (2001) L 909 -05: 20

Stylesheets and Markup Cascading Style Sheets n Cascading Style Sheets (CSS) allows authors to Stylesheets and Markup Cascading Style Sheets n Cascading Style Sheets (CSS) allows authors to define style rules to each HTML element and these rules may apply to either: n single elements n a related group of elements, or to n all elements of a particular type (such as all P elements) Clarke, R. J (2001) L 909 -05: 21

Stylesheets and Markup Style Rules in CSS (1) n style rules influence the rendering Stylesheets and Markup Style Rules in CSS (1) n style rules influence the rendering of elements n colour, alignment, border, margins, and padding between borders and content n can also control special items eg. whether Ordered List (OL) elements use bullet symbols, letters or roman numerals Clarke, R. J (2001) L 909 -05: 22

Stylesheets and Markup Style Rules in CSS (2) n every style rules have two Stylesheets and Markup Style Rules in CSS (2) n every style rules have two parts: n one or more elements or groups of elements that have style sheets defined for them n one or more style sheet attributes that apply to the elements n then need to relate or bind stylesheets to HTML elements (eg. to all P elements)several possible approaches Clarke, R. J (2001) L 909 -05: 23

Stylesheets and Markup Approaches of Binding n two major approaches to binding stylesheets to Stylesheets and Markup Approaches of Binding n two major approaches to binding stylesheets to HTML elements n in-document styles n importing external stylesheets n the choice of approach depends on: n the size and complexity of the web site n the size of the development team n user community diversity and expertise Clarke, R. J (2001) L 909 -05: 24

Stylesheets and Markup In-Document Style Binding (1) : <BODY> <H 1 STYLE= “color: red; Stylesheets and Markup In-Document Style Binding (1) : Some heading

Some paragraph text

: Note: almost every HTML element can have a STYLE attribute associated with it n One form of In-Document Style Binding associates a style declaration to an HTML element using the elements’ STYLE attribute n Usage: n convenient if style rules are few and simple n difficult to maintain in large sites as changes must be made throughout the HTML file Clarke, R. J (2001) L 909 -05: 25

Stylesheets and Markup In-Document Style Binding (2) <HTML> <HEAD> <STYLE TYPE =“text/css”> <!-H 1 Stylesheets and Markup In-Document Style Binding (2) older browsers from : trying to render them : : Some heading

Some paragraph text

n Another form of In. Document Style Binding is to define and group together all style rules between tags n Usage: n better option when trying to maintain a moderately complex page n promotes modular design and implementation of page Clarke, R. J (2001) L 909 -05: 26

Stylesheets and Markup Binding using External Stylesheets H 1 {color: red; text-transform: capitalize} P Stylesheets and Markup Binding using External Stylesheets H 1 {color: red; text-transform: capitalize} P {color: blue} Note: these style rules are stored in the file called mystyles. css : Note: rules are applied to HTML file on the fly Some heading

Some paragraph text

n Define and apply an external style sheet file to one or more HTML files n the external style sheet file (above, left) contains only rules no HTML tags n Usage: n promotes a consistent look similar to work processor style sheets n separates the documents’ structure and look Clarke, R. J (2001) L 909 -05: 27

Stylesheets and Markup Difficulties with HTML (1) n While the CSS Level 1 is Stylesheets and Markup Difficulties with HTML (1) n While the CSS Level 1 is consistent across major browsers, it doesn’t provide exact positioning of elements on a page n the CSS Level 2 standard supports exact positioning but there are differences in implementation across major browsers n CSS Level 2 has many advantages but in order to preserve the same look developers may be forced to use Level 1 - or undertake a major development task! Clarke, R. J (2001) L 909 -05: 28

Stylesheets and Markup Difficulties with HTML (2) n there is a much more serious Stylesheets and Markup Difficulties with HTML (2) n there is a much more serious problem: n the stylesheet and descriptive markup capabilities of HTML 4. 0 and DHTML (HTML 5. 0), were not built into it from the start n describing the structure is not the same thing as descriptive markup n users cannot create there own tags based on meanings (semantics)- for example no tags for PART NUMBER or COURSE- HTML not extensible Clarke, R. J (2001) L 909 -05: 29

Stylesheets and Markup Difficulties with HTML (3) n on the Internet simplicity wins over Stylesheets and Markup Difficulties with HTML (3) n on the Internet simplicity wins over efficiency- the Web has grown because its core standards are simple: n proof of this is that HTML is itself written using another standard for describing documents- this standard is called SGML n SGML has also been used to develop a standard likely to replacement HTML on the web- XML described in Lecture 13 Clarke, R. J (2001) L 909 -05: 30

SGML Standard Clarke, R. J (2001) L 909 -05: 31 SGML Standard Clarke, R. J (2001) L 909 -05: 31

SGML Standard n internationally recognised standard (ISO 8879) for describing and enforcing structure and SGML Standard n internationally recognised standard (ISO 8879) for describing and enforcing structure and properties onto data in computer base information systems, including semi-structured data n completely descriptive markup system for document content n open environment for the interchange of a portable generic format between platforms Clarke, R. J (2001) L 909 -05: 32

SGML Standard Features (1) n major features: n syntax for text processing stylesheets n SGML Standard Features (1) n major features: n syntax for text processing stylesheets n extensible document description language n meta-language for defining document types n text media support: n text is coded according to its meaning- can be used in way not originally envisioned n tagging language n database language for text Clarke, R. J (2001) L 909 -05: 33

SGML Standard Features (2) n media processing applications: n foundation for multimedia and hypertext- SGML Standard Features (2) n media processing applications: n foundation for multimedia and hypertext- Hy. Time (an ISO standard) is an SGML application that knows about multimedia, time-based events, synchronisation n general computational features: n handles logical structures (conditional documents) n notation for structures (eg. hierarchies): sequences, repetitions and selections Clarke, R. J (2001) L 909 -05: 34

SGML Standard Features (3) n other aspects: n general file linking and addressing scheme SGML Standard Features (3) n other aspects: n general file linking and addressing scheme n open document representation language for any system architecture n supports open inter-communication regardless of hardware platforms and software applications Clarke, R. J (2001) L 909 -05: 35

SGML Standard Instances & Document Type Definition n An SGML document is text only, SGML Standard Instances & Document Type Definition n An SGML document is text only, but has the following structure: n an document instance containing the data n a document type definition (DTD) defining what data elements can be in the document, and how these data elements relate to each other Clarke, R. J (2001) L 909 -05: 36

SGML Standard Document Instances n document instances contain data and markup (called tags): n SGML Standard Document Instances n document instances contain data and markup (called tags): n both data and tags are in ASCII format- read by any application n tags are distinguishable from data: tags always have pairs of <> brackets n some system specific data can be inserted into the instance using special tagsremoves the need for control codes etc Clarke, R. J (2001) L 909 -05: 37

SGML Standard Document Type Definition (1) n can be stored at the beginning of SGML Standard Document Type Definition (1) n can be stored at the beginning of the document or externally in a separate file (generally the latter) n consist of all the formal definition of the elements, structures, and rules for marking up a given type of SGML document Clarke, R. J (2001) L 909 -05: 38

SGML Standard Document Type Definitions (2) n comprise rules and relationships that define how SGML Standard Document Type Definitions (2) n comprise rules and relationships that define how the different elements within a document relate to each other: n specify the order in which headings occur n which elements are allowed under each heading n the order and frequency with which elements should appear Clarke, R. J (2001) L 909 -05: 39

SGML Standard Document Type Definitions (3) n specifies the permitted document elements n eg. SGML Standard Document Type Definitions (3) n specifies the permitted document elements n eg. ‘Chapter’, ‘Heading’, ‘Definition-entry’, ‘Defined-work’, ‘Definition’ and ‘See-also’ n each element typically has a content model stating its required or permitted contents. n eg. the content model for ‘Definition-entry’ would state that it must have only one ‘Defined-word’ and ‘Definition’ n ‘Defined-word’ and ‘Definition’ must also be described by content models Clarke, R. J (2001) L 909 -05: 40

Document Type Definition Extract of an SGML Memo DTD <! -- DTD for simple Document Type Definition Extract of an SGML Memo DTD : : : : Clarke, R. J (2001) L 909 -05: 41

SGML Processing Systems (1) n read a document instance, and refers to a DTD SGML Processing Systems (1) n read a document instance, and refers to a DTD to find out how to process it n aspects of the document instance such as format of the page, fonts spacing etc. are not defined in SGML (a distinction between Post. Script for example and SGML) n must exist in heterogeneous environments where not all documents are in SGML Clarke, R. J (2001) L 909 -05: 42

SGML Processing Systems (2) SGML Data Application Library SGML DTD SGML Parser SGML Processing SGML Processing Systems (2) SGML Data Application Library SGML DTD SGML Parser SGML Processing System Application Output Clarke, R. J (2001) L 909 -05: 43

SGML Processing Systems (3) Tag Application New Data SGML Applications New Data Legacy Documents SGML Processing Systems (3) Tag Application New Data SGML Applications New Data Legacy Documents Graphics Files Non-SGML Editing System SGML Files SGML Edit/Convert Bitmap Edit/Convert Clarke, R. J (2001) L 909 -05: 44

DSSSL n Document Style Semantics and Specification Language (DSSSL) n is the ISO international DSSSL n Document Style Semantics and Specification Language (DSSSL) n is the ISO international standard (ISO DIS 10179) which addresses the need for detailed, typographically sophisticated, specification of layout and composition n independent of particular formatting systems or processes Clarke, R. J (2001) L 909 -05: 45

SGML Example Clarke, R. J (2001) L 909 -05: 46 SGML Example Clarke, R. J (2001) L 909 -05: 46

SGML Example Informational Content Markup n the following two slides shows an extract from SGML Example Informational Content Markup n the following two slides shows an extract from a Vincent motorcycle repair manual n show the informational content markup using SGML n note that SGML tags are usually shown in the form <…> followed by Clarke, R. J (2001) L 909 -05: 47

Information Markup (Source: Nicholson Brothers Motorcycles Ltd. 1994) Clarke, R. J (2001) L 909 Information Markup (Source: Nicholson Brothers Motorcycles Ltd. 1994) Clarke, R. J (2001) L 909 -05: 48

Information Markup (continued) (Source: Nicholson Brothers Motorcycles Ltd. 1994) Clarke, R. J (2001) L Information Markup (continued) (Source: Nicholson Brothers Motorcycles Ltd. 1994) Clarke, R. J (2001) L 909 -05: 49

SGML Benefits Clarke, R. J (2001) L 909 -05: 50 SGML Benefits Clarke, R. J (2001) L 909 -05: 50

SGML Benefits n DTD structure forces the user to focus on document content not SGML Benefits n DTD structure forces the user to focus on document content not format n SGML helps the authors by: n suggesting the correct structure of different document types n enforces the correct structure: if an author attempted to put in non-standard material, the application would refuse to accept it Clarke, R. J (2001) L 909 -05: 51

SGML Benefits n Data Management n common data repository for the enterprise n standardised SGML Benefits n Data Management n common data repository for the enterprise n standardised formatting for information n minimise data duplication n control/check data quality n maximises the benefit of data entry and authoring Clarke, R. J (2001) L 909 -05: 52

SGML Benefits n facilitates data exchange within an enterprise (Intranets) n prevents islands of SGML Benefits n facilitates data exchange within an enterprise (Intranets) n prevents islands of information forming within the organisation (that is information trapped within specific functional areas) n prevents an ‘isolationist mentality’ forming within specific functional areas (‘marketing’ data rather than organisational asset) Clarke, R. J (2001) L 909 -05: 53

SGML Benefits n facilitiates data exchange between an organisation and business partners (Extranets; EDI) SGML Benefits n facilitiates data exchange between an organisation and business partners (Extranets; EDI) n promotes participation between partners n reduces costs, improves performance n streamlines operations and maangement practices, reduces ‘bottlenecks’ Clarke, R. J (2001) L 909 -05: 54

SGML Benefits Video Case Studies about EDI n Note that SGML could well have SGML Benefits Video Case Studies about EDI n Note that SGML could well have been an enabling technology for EDI in these CASE Studies n take notes on how these EDI systems were negotiated- what are the Tactical Strategic and Operation implications suggested in these cases Clarke, R. J (2001) L 909 -05: 55

Adopting SGML Clarke, R. J (2001) L 909 -05: 56 Adopting SGML Clarke, R. J (2001) L 909 -05: 56

Adopting SGML n Data Analysis n Feasilbility Study n Standardising Data Concepts n Data Adopting SGML n Data Analysis n Feasilbility Study n Standardising Data Concepts n Data Entry & Document Conversion n Delivery of Data to Users Clarke, R. J (2001) L 909 -05: 57