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					Network publishing and mark-up languages
                                    p- versus e-form

   The share of documents in e-form and accessible
    over the network is growing fast.
   There are types of documents that will “always”
    exist in a paper form or co-exist in both forms.
   There are numerous types of documents that
    already function better in e-form, at least for
    some populations (or generations).
   The e-document can replace the paper form only
    if it is readable without limits of time and place.
     Alpe Adria Master Course :: Medical Informatics :: Dr. J. Dimec: Web publishing and mark-up languages.   2
                           Independence of place
   Document should be usable in the same way
    irrespective of server’s distance and user’s
    hardware and software for reading.
   It is mainly a technological problem. We need
         a reader of a size and weight of a book,
         with screen with visual characteristics of a paper,
         with autonomous power supply,
         with wireless connection to servers with documents.
   All that we already have, but not in one
    reasonably expensive appliance.
     Alpe Adria Master Course :: Medical Informatics :: Dr. J. Dimec: Web publishing and mark-up languages.   3
                            Independence of time

   Document must have the same usability until
    potential readers disappear.
   It is mainly an organisational problem:
         we need standard document formats, which will be
          understood by future generations of software and
          hardware, and
         we need consensus to obey those standards.
   Such standard formats are made by mark-up
    languages.
     Alpe Adria Master Course :: Medical Informatics :: Dr. J. Dimec: Web publishing and mark-up languages.   4
                          History of e-publishing
   At the beginning the creators of e-documents
    were few, mostly creators of bibliographic
    databases.
   They independently developed formats of their e-
    documents and software for their use.
   It was easy because e-documents were simple,
    ASCII files.
   Things became complicated with the
    development of more complicated, multimedia
    documents.
     Alpe Adria Master Course :: Medical Informatics :: Dr. J. Dimec: Web publishing and mark-up languages.   5
                          History of e-publishing
   Because of the lack of standardisation new
    documents were not usable by definition on every
    operating system and brand of computer.
   Producers of e-documents were forced to develop
    different versions of documents and/or software
    for its use for all major brands of OS and
    computers.
   It was economically unfeasible and the only exit
    was standardisation.
   Standardisation of computers? Impossible.
    Standardisation of e-document formats.
     Alpe Adria Master Course :: Medical Informatics :: Dr. J. Dimec: Web publishing and mark-up languages.   6
            Mark-up languages: introduction



   Mark-up languages must make possible:
         the transfer of documents between different types of
          computers and software for reading,
         simple and economical transport through networks,
         longevity of documents (problem of e-archiving).
   Mark-up languages enable us to mark structure
    and/or form (appearance) of documents.

     Alpe Adria Master Course :: Medical Informatics :: Dr. J. Dimec: Web publishing and mark-up languages.   7
            Mark-up languages: introduction


   Mark-up languages are artificial languages,
    composed of:
         labels (tags) that divide document into structural
          elements,
         tags that describe appearance of structural elements,
          and
         syntax that defines appropriate use of tags.



     Alpe Adria Master Course :: Medical Informatics :: Dr. J. Dimec: Web publishing and mark-up languages.   8
                        Structure vs. appearance

   If mark-up language defines only structure of a
    document, then its appearance on a screen or
    paper is entirely dependent on the software used
    for document’s representation.
   In such case the structure of document is
    separated from definitions of fonts, colour of
    background, distance between lines, etc. With
    such attributes of documents the printing-house
    mark-up languages are dealing.

     Alpe Adria Master Course :: Medical Informatics :: Dr. J. Dimec: Web publishing and mark-up languages.   9
                                                    RTF
   Very common type of e-documents are
    documents written with word processors, e.g. MS
    Word for Windows.
   Structure and appearance of documents are
    inseparable.
   The result is very limited possibility of transfer of
    documents between different types of computers
    or operating systems; even between different
    generations of same word processor.
   More advanced is word processor, more closed
    system it is.
     Alpe Adria Master Course :: Medical Informatics :: Dr. J. Dimec: Web publishing and mark-up languages.   10
                                                    RTF

   A strong need exist for transportability of word
    processor files.
   Developers of word processors agreed upon the
    common transport format, which is understood by
    the most programmes of that kind.
   This is RTF – Rich Text Format.
   RTF denotes only document’s appearance.



     Alpe Adria Master Course :: Medical Informatics :: Dr. J. Dimec: Web publishing and mark-up languages.   11
                                          RTF: example
{\rtf1\ansi\deff20\deflang1033{\fonttbl{\f4\froman\fchars
et0\fprq2 Times New Roman;}{\f5\fswiss\fcharset0\fprq2
Arial;}{\f20\fnil\fcharset0\fprq2 SLOHelvetica;}}
{\colortbl;\red0\green0\blue0;\red0\green0\blue255;
... 20 to 30 lines of lines with general description of fonts and distances follow ...
\pard\plain \qr\sb40\sa40\tx357 \f20\fs20\lang2057
{\fs18 Lecture: Computer communications, Databases 2}
\par \pard\plain \s18\sb40\sa40\tx357 b\f20\fs30\lang2057
{\i\fs32 Predavanje: Standardi za označevanje dokumentov
\par }\pard\plain \s1\fi-360\li360\sb240\sa40\tx357
\b\f20\fs28\lang2057
1.\tab Reasons for standardisation of document descriptio

    tags for types and colours                                tags for text positioning
    of fonts

        Alpe Adria Master Course :: Medical Informatics :: Dr. J. Dimec: Web publishing and mark-up languages.   12
                               Postscript and PDF
Postcript (Adobe):
        Mark-up language for driving laser printers.
        Marks only document’s appearance, including
         images.
PDF (Portable Document Format):
        Makes possible the original appearance of a
         document on a web browser.
        Documents on screen look the same as on the paper.
        Simplified and upgraded variant of Postscript.
        Marks appearance and only partly structure (hyper-
         text pointers).

    Alpe Adria Master Course :: Medical Informatics :: Dr. J. Dimec: Web publishing and mark-up languages.   13
                                                 SGML
SGML: Standard Generalized Mark-up Language.
 International standard, adopted by ISO on 1986
  and upgraded several times since then.
 Family of standards, managing the mark-up of all
  known types of e-documents.
 Its strength is generality, because logical
  structure and appearance of a document are
  completely separated.
   Appearance is left to software for representation
    of documents on screen or paper.
     Alpe Adria Master Course :: Medical Informatics :: Dr. J. Dimec: Web publishing and mark-up languages.   14
                                                 SGML

SGML divides e-document into three parts:
 Declaration, which describes the most general data about
  document (Latin or Cyrillic script…) and symbols with
  special meaning for SGML.
 Document Type Definition (DTD), which describes the
         possible structural elements of document,
         their meaning,
         hierarchical relationship among structural elements, and
         tags that mark these structural elements.
   Body of a document, marked with tags.

     Alpe Adria Master Course :: Medical Informatics :: Dr. J. Dimec: Web publishing and mark-up languages.   15
                                                 HTML
   SGML is not a real mark-up language but a
    recipe how to build mark-up languages for
    different types of documents.
   HTML is such language developed for web
    documents.
   It is relatively simple and this is the reason for
    extreme simplicity of web publishing.
   In its original versions it mostly defines structure
    and only partly appearance of documents.
   Author: Tim Berners-Lee (early 90’s).
     Alpe Adria Master Course :: Medical Informatics :: Dr. J. Dimec: Web publishing and mark-up languages.   16
                                                 HTML
   The standardisation of HTML is endangered
    since its birth.
   Big producers of web browsers, Microsoft and
    Netscape try to impose their own tags and
    functionality to beat the competition.
   Documents written with some word processors
    for HTML can not be read on browsers made by
    competition.
   It is safe to use simple Notepad or Netscape’s
    editor.
     Alpe Adria Master Course :: Medical Informatics :: Dr. J. Dimec: Web publishing and mark-up languages.   17

				
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