newbie:importance of XML?

Discussion in 'XML' started by Vishnu, Dec 22, 2003.

  1. Vishnu

    Vishnu Guest

    Hello guys

    I have been reading about XML for the past few days,but i needed some
    clarification as to the importance of XML.From what i understood:

    * XML is a way to organize data and manipulate on it.There are other
    things like XSL which helps to display it in any format.
    * XML has got broad acceptance as a standard which is one of the
    reasons why its so popular.

    But what i dont understand is:

    * Most of the articles i read says XML helps us to define new
    languages.Can someone explain me how XML does this and also some
    practical examples?

    * Is XML just another way to organize data?Because if this was the
    case,then one could have send some data in .txt format to the
    receiver.If receivcer can interpret this data,then all is done.And if
    this 'sending of .txt data' is made uniform throughout,then we have
    got a universal way to send and organize data,right?What iam asking
    is:IS THIS XML'S LOGIC?

    * One more query on sending of data.I read xml data can be send to any
    devices provided it gives support.But when you have say,10000
    data,then the XML file would be very large right?What advantage you
    get by sending data in xml format[other than interoperatability]?

    Iam sorry if the question is irrevelant.But i will be very thankful to
    you if you can give me some basic information regarding these
    questions.

    --Vishnu--
     
    Vishnu, Dec 22, 2003
    #1
    1. Advertising

  2. In article <>,

    [...]


    % * Most of the articles i read says XML helps us to define new
    % languages.Can someone explain me how XML does this and also some
    % practical examples?

    What XML _is_ is a language for defining data mark-up languages. When
    people go on and on and on about XML, they're often talking about
    some language which has been defined using XML (the rest of the time,
    they're mostly just filling the void with nonsense). Languages defined
    in XML have a number of common characteristics, the most obvious of which
    are

    - they divide data into named units called elements
    - elments can have content, which can consist of text data and other
    elements
    - elements can have named bits of data, called attributes
    - the way the data is marked up (i.e., how elements are written
    in a file, how comments are written, how special characters are
    escaped) is the same for all XML documents

    XML provides two benefits: it reduces the work to define new languages,
    and it reduces the work to write language processing software. To define
    a new language, it's sufficient to define its structure, that is, the
    names of the elements and the way they nest together. The precise syntax
    of the language follows from that directly. It means you can define a
    new XML language in a few lines: the document element is `config-file'.
    It has one repeated child element, `item', which has one required
    attribute `name'. From that, you know

    <config-file>
    <item name='root-dir'>/usr/home/ptjm</item>
    <item name='default-emoticon'><![CDATA[<:)]]</item>
    </config-file>

    is a valid document according to this new language. On the processing side,
    the same software can be used to convert any XML file into data structures,
    so you don't need to write a parser for each new language you want to use.
    In some cases (for instance, in an editor), the processing to be performed
    can be inferred from the document structure, so the same piece of code can
    be used to completely process any XML file. In other cases, XML helps with
    one small piece of the application, but doesn't appreciably reduce the
    effort to produce an application as a whole.

    % case,then one could have send some data in .txt format to the
    % receiver.If receivcer can interpret this data,then all is done.

    Sure. The question is how to define the .txt format. I use a simple
    configuration file format above because it's quick to define, but in
    that case, it would be just as easy for me to say `use windows .ini
    format with this section name and these parameter names' or `use X
    resource file format with these resource names', or `use a tab-delimited
    file with the configuration item name in the first field and the
    value taking up the rest of the line. For a format with any degree of
    complexity, the syntactic conventions that XML forces on you become
    a more important part of the language definition, and it becomes
    easier to define the language using XML than using some ad hoc text
    format.

    % * One more query on sending of data.I read xml data can be send to any
    % devices provided it gives support.

    This is a fine example of filling the void with nonsense. You can send
    PDF data to any device, provided it gives support. You can send mud
    pies. You can write instructions in esperonto and any device can process
    them, provided they understand esperonto.


    % But when you have say,10000
    % data,then the XML file would be very large right?What advantage you
    % get by sending data in xml format[other than interoperatability]?

    If you have a lot of data, you have a lot of data. XML does nothing
    to help with this.
    --

    Patrick TJ McPhee
    East York Canada
     
    Patrick TJ McPhee, Dec 22, 2003
    #2
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. Replies:
    5
    Views:
    497
    Darryl L. Pierce
    Jan 30, 2006
  2. eas

    terms of importance

    eas, Jan 17, 2004, in forum: C++
    Replies:
    13
    Views:
    609
    Risto Lankinen
    Jan 19, 2004
  3. ASP.NET
    Replies:
    1
    Views:
    2,327
    Patrice
    Jul 17, 2006
  4. Amarendra GODBOLE
    Replies:
    25
    Views:
    704
    Dan Pop
    Jan 21, 2004
  5. Doug Tolton
    Replies:
    1
    Views:
    341
    Doug Tolton
    Aug 13, 2003
Loading...

Share This Page