Tuesday 30 January

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• 9.00-10.30: 1.1. Introductions (Edward Vanhoutte)
  • This Workshop
  • XML: a first successful attempt
• 11.00-12.30: 1.2. Hypertextual Structures of Complex Writing Processes (Dirk Van Hulle)
• 13.30-15.00: 1.3. Versions and Compositional Variants (Dirk Van Hulle)
• 15.30-17.00: 1.4. Text-encoding, Markup, XML and TEI (Edward Vanhoutte)
  • Workflow
  • Why Electronic Texts?
  • Text encoding & markup
  • The Text Encoding Initiative
  • Why XML?
  • Document analysis
  • Structure and contents
  • Markup
  • OHCO
  • DTD

Workflow: mantra in 9 lines

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1. Project definition
2. Document analysis
3. Encoding design
4. Coding
5. Validating
6. Functionality: storyboard
7. Transform, generate, implement
8. Document
9. Publish

Why electronic texts? Macro level

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1. digitally created (born digital)
2. digitized

1. technological progress
2. • create access to material
   • support preservation policy
   • collection acquisition/completion
   • flexible use
   • institutional and strategic advantage (prestige)
   • research
   • education

2 different strategies

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1. Short term thinking
   • document creation/production
   • print
   • mail
   • document lay-out
   • ease of the word processor
   • WYSIWYG interface
   • → .rtf, .doc, .wpd, .pdf, .xls, .dmb
   • → Word, WordPerfect, Adobe Acrobat, Excel, Access
2. Long term thinking
   • justify investments
   • retain access to material
   • maintain project
   • exchange of data
   • document structure
   • → ISO standards and W3C norms

Why electronic texts? Micro level

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• Research question
• Specific history and story of your text
• Your institutional context
• Your mehodological network

2 Main Problems

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• Interchange between systems and platforms causes loss of information
  → Short data life cycle
• Loss of semantic information in translation to visual information

Solution

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• is software and platform independent
• can describe the logical, structural, and semantic elements of a text

Solution

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• is software and platform independent
• can describe the logical, structural, and semantic elements of a text

William Gibson é um guru do
 <language what="English">science fiction</language>
 e <title>Neuromancer</title> é seu 
 <language what="English">masterpiece</language>
 <term>cyberpunk</term>

XML: eXtensible Markup Language

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• W3C recommendation
• The standard on the internet
• Widely used standard for markup and exchange of information

XML: What it is

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• XML is stuctured data, represented as strings of text
• XML is platform-, software-, and system-independent
• No one 'owns' XML
• XML empowers the content provider and facilitates data integration, exchange, maintenance and extraction.
• XML is an SGML system application
• So it looks a bit like HTML, except that
  • XML is extensible
  • XML must be well-formed
  • XML can be validated

(S)GML - XML: A bit of history

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• Need for a platform and software independent format for data storage and interchange
• IBM: Generalized Markup Language (GML)
• ISO 8879:1986: Standard Generalized Markup Language (SGML): Charles Goldfarb
• SGML is a meta-language: a language for the description of markup languages
• Markup languages are commonly named after their
  • document type definition (DocBook)
  • aim (LinuxDoc)
  • application (TEI)
  • the standard they implement (J2003: automobile parts)
• The DTD is the core of an SGML system
• SGML is the solution for the industry: expensive and complicated but at the same time very powerful

What is a DTD (for now)?

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• Poetry
• Prose
• Drama
• Letters
• Bibliographies
• Dictionaries
• Lists
• ...

SGML - ISO 8879:1986

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• Comprehensiveness.
• Simplicity.
• Documents be processable by software of moderate complexity.
• Standard not be dependent on any particular characteristic set or text-entry devise.
• The standard not be geared to any particular analytic program or printing system.
• The standard should describe text in editable form.
• The standard allow the interchange of encoded texts across communication networks.

The Text Encoding Initiative (TEI)

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• Platform-independent
• Software-independent
• Endurability
• Re-usability
• Accessibility
• Language-independent
• For all of the Humanities disciplines

TEI Short History

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• 1987: Vassar College, Poughkeepsie
• 1990: P1 : SGML
• 1992: P2 : SGML
• 1994: P3 : SGML : 600 + elements
• 1995: TeiLite : SGML : 131 elements
• 1999: P3rev : SGML
• 2000: TEI Consortium
• 2001: P4 : XML comp
• 2001: TeixLite : XML
• 2005-2007: P5 : XML

So: Why would you want to learn about XML? The short answer:

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• It's a good approximation
• It works (fairly well)
• It's widely supported
• It's a W3C recommendation

Why XML? The longer answer:

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• Internationally suported (de facto) standard:
  • W3C recommendation
  • wide support
• Software and platform independent
• Describes the logical, structural, as well as semantic elements of a text
• Relatively easy to master
• Self declarative: for the machine and for human beings
• Low creation cost thanks to open source support
• Design of XML is formal and concise (Extended Backus-Naur Format - EBFN)
• It is relatively easy to write programs which process XML documents.
• Internationalisation: Unicode
• Flexible output
• Can be used with existing web protocols (HTTP) and mechanisms (URL)
• Related standards in the XML family empower XML: XSLT, XSLFO, XPath, XQuery, Xlink, etc.

Why would you want to learn about XML?

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• XML will develop into ... ?
• Other standards

Why would you want to learn about XML?

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• XML will develop into ... ?
• Other standards

• Migration will be supported
• Migration will create more jobs

Why would you want to learn about TEI?

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• Best guarantee for intellectual sustainability of your research efforts.
• Supported by a community
• No 'take it or leave' it approach: extendible, modifiable
• It's free

Workflow: mantra in 9 lines

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1. Project definition
2. Document analysis
3. Encoding design
4. Coding
5. Validating
6. Functionality: storyboard
7. Transform, generate, implement
8. Document
9. Publish

What is markup really?

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• stable agreements on ontology and semantics
• a community who knows these agreements

Text encoding and markup

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• Texts are more than simply sequences of glyphs
  → They have structure and content and they also have multiple readings

Workflow: mantra in 9 lines

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1. Project definition
2. Document analysis
3. Encoding design
4. Encoding
5. Validating
6. Functionality: storyboard
7. Transform, generate, implement
8. Document
9. Publish

Text encoding and markup

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• Texts are more than simply sequences of glyphs
  → They have structure and content and they also have multiple readings
• Text encoding or markup provides a means of making such structure, content, and readings explicit

Texts have structure and content 1

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POOREDWARDDIDYOUHEARTHENEWSABOUTEDWARD?ONTHEBACKOFHISHE
ADHEHADANOTHERFACEWASITAWOMAN'SFACEORAYOUNGGIRLTHEYSAID
TOREMOVEITWOULDKILLHIMSOPOOREDWARDWASDOOMEDTHEFACECOULD
LAUGHANDCRYITWASHISDEVILTWINANDATNIGHTSHESPOKETOHIMTHIN
GSHEARDONLYINHELLBUTTHEYWEREIMPOSSIBLETOSEPARATECHAINED
TOGETHERFORLIFEFINALLYTHEBELLTOLLEDHISDOOMHETOOKASUITEO
FROOMSANDHUNGHIMSELFANDHERFROMTHEBALCONYIRONSSOMESTILLB
ELIEVEHEWASFREEDFROMHERBUTIKNEWHERTOOWELLISAYSHEDROVEHI
MTOSUICIDEANDTOOKPOOREDWARDTOHELL

Texts have structure and content 2

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Poor Edward. Did you hear the news about Edward? On the back of
his head he had another face. Was it a woman's face or a
young girl? They said to remove it would kill him, So poor
Edward was doomed. The face could laugh and cry. It was his devil
twin. And at night she spoke to him things heard only in hell. But
they were impossible to separate, Chained together for life. Finally
the bell tolled his doom. He took a suite of rooms and hung himself
and her from the balcony irons. Some still believe he was freed
from her, but I knew her too well. I say she drove him to suicide,
and took poor Edward to hell.

Texts have structure and content 3

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Poor Edward

Did you hear the news about Edward?
On the back of his head he had another face
Was it a woman's face or a young girl?
They said to remove it would kill him
So poor Edward was doomed

The face could laugh and cry
It was his devil twin
And at night she spoke to him
Things heard only in hell
But they were impossible to separate
Chained together for life

Finally the bell tolled his doom
He took a suite of rooms
And hung himself and her from the balcony irons
Some still believe he was freed from her
But I knew her too well
I say she drove him to suicide
And took poor Edward to hell

Texts have structure and content 4

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Poor Edward

<line>Did you hear the news about Edward?</line>
<line>On the back of his head he had another face</line>
<line>Was it a woman's face or a young girl?</line>
<line>They said to remove it would kill him</line>
<line>So poor Edward was doomed</line>

<line>The face could laugh and cry</line>
<line>It was his devil twin</line>
<line>And at night she spoke to him</line>
<line>Things heard only in hell</line>
<line>But they were impossible to separate</line>
<line>Chained together for life</line>

<line>Finally the bell tolled his doom</line>
<line>He took a suite of rooms</line>
<line>And hung himself and her from the balcony irons</line>
<line>Some still believe he was freed from her</line>
<line>But I knew her too well</line>
<line>I say she drove him to suicide</line>
<line>And took poor Edward to hell</line>

Texts have structure and content 5

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Poor Edward

<stanza>
<line>Did you hear the news about Edward?</line>
<line>On the back of his head he had another face</line>
<line>Was it a woman's face or a young girl?</line>
<line>They said to remove it would kill him</line>
<line>So poor Edward was doomed</line>
</stanza>

<stanza>
<line>The face could laugh and cry</line>
<line>It was his devil twin</line>
<line>And at night she spoke to him</line>
<line>Things heard only in hell</line>
<line>But they were impossible to separate</line>
<line>Chained together for life</line>
</stanza>

<stanza>
<line>Finally the bell tolled his doom</line>
<line>He took a suite of rooms</line>
<line>And hung himself and her from the balcony irons</line>
<line>Some still believe he was freed from her</line>
<line>But I knew her too well</line>
<line>I say she drove him to suicide</line>
<line>And took poor Edward to hell</line>
</stanza>

Texts have structure and content 6

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<poem>
<title>Poor Edward</title>

<stanza>
<line>Did you hear the news about Edward?</line>
<line>On the back of his head he had another face</line>
<line>Was it a woman's face or a young girl?</line>
<line>They said to remove it would kill him</line>
<line>So poor Edward was doomed</line>
</stanza>

<stanza>
<line>The face could laugh and cry</line>
<line>It was his devil twin</line>
<line>And at night she spoke to him</line>
<line>Things heard only in hell</line>
<line>But they were impossible to separate</line>
<line>Chained together for life</line>
</stanza>

<stanza>
<line>Finally the bell tolled his doom</line>
<line>He took a suite of rooms</line>
<line>And hung himself and her from the balcony irons</line>
<line>Some still believe he was freed from her</line>
<line>But I knew her too well</line>
<line>I say she drove him to suicide</line>
<line>And took poor Edward to hell</line>
</stanza>

</poem>

2 Operable Conditions

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• Markup should be separated from content
• Markup should be processable → logical & predictable

Markup should be separated from content

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<tag>content</tag>

Markup should be processable

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• Logical
• Predictable

Markup Model for a Book

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<book>
  <chapter n="1">
    <section n="1">
      <p>...</p>
      <p>...</p>
    </section>
    <section n="2">
      <p>...</p>
      <p>...</p>
    </section>
  </chapter>
  <chapter n="2">
    <!-- more sections and paragraphs -->
  </chapter>
</book>

Markup should be processable

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• Logical
• Predictable

Document Type Definition (DTD)

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• Poetry
• Prose
• Drama
• Letters
• Bibliographies
• Dictionaries
• Lists
• ...

Document Type Definition (DTD)

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• Poetry
• Prose
• Drama
• Letters
• Bibliographies
• Dictionaries
• Lists
• ...

Document Type Definition (DTD)

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• names for all your elements
• names and default values for their attributes
• rules about how elements can nest
• names for re-usable pieces of data (entities)
• and a few other things

Summary

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• Computers work with representations of text
• Proprietary software merges structure, content, meaning, and layout in one code
  → 2 problems
  • Short data life cycle
  • Visual information = semantic information
• Solution: standard for text encoding
  → Markup explicitly articulates structure, content, and readings
• Markup should be separated from content
  → Tags
• Markup should be processable
  → OHCO thesis
• A markup language is defined by its Document Type Definition

How do we recognize an XML document?

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<?xml version="1.0" ?>

• ?: Processing Instruction
• xml: this is XML
• version="1.0": specifies which version of the spec is used here

How do we recognize an XML document?

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<?xml version="1.0" ?>

• ?: Processing Instruction
• xml: this is XML
• version="1.0": specifies which version of the spec is used here

<root>Content</root>

Minimal XML document

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<?xml version="1.0" ?>

<root>Hello world</root>

XML jargon

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• Processing Instructions
• Elements
• Attributes (optional)
• Entity References
• CDATA

XML jargon

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• Processing Instructions
• Elements
• Attributes (optional)
• Entity References
• CDATA

<?xml version="1.0" ?>

<?xml-stylesheet href="../dtd/xsltslides.xsl" type="text/xsl" ?>

XML jargon

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• Processing Instructions
• Elements
• Attributes (optional)
• Entity References
• CDATA

<title> or </title>

XML jargon

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• Processing Instructions
• Elements
• Attributes (optional)
• Entity References
• CDATA

<element.name  attribute.name="attribute.value">

<title  type="journal">

<name  who="Edward"  reg="VanhoutteE" >

XML jargon

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• Processing Instructions
• Elements
• Attributes (optional)
• Entity References
• CDATA

• to represent characters which cannot reliably be typed in
• as a shortcut for boiler plate text
• containers for external (non-XML) data such as graphics

&entity.name;

é = é = é

ü = ü = ü

&mayonnaise; = reference to an external recipe (text) for mayonnaise

<figure  entity="ascii-full" />

Character entities

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• XML requires the use of ISO/IEC 10646 or Unicode
  • Unicode is a standard, by the Unicode Consortium, which defines a character repertoire and character code intended to be fully compatible with ISO 10646, and an encoding for it.
  • Unicode "imposes additional constraints on implementations to ensure that they treat characters uniformly across platforms and applications". (section Unicode & ISO 10646 of the Unicode FAQ <http://www.unicode.org/unicode/faq/>)
  • a 32 bit character repertoire including most human writing systems
  • encoded as UTF8 (Web), UTF16 (Java and Windows), or UTF32 (Unix).
• Other encodings may be specified at the document level

Entity Declaration

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<!ENTITY eacute  "&#233;" ><!-- small e, acute accent -->

<!ENTITY TEI  "Text Encoding Initiative">

<!ENTITY allc SYSTEM "../graphics/allc.gif" NDATA gif>

XML jargon

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• Processing Instructions
• Elements
• Attributes (optional)
• Entity References
• CDATA

<![CDATA[This text escapes the XML processor]]>