[Sussex] 2 questions (probably stupid)
Mark Harrison
Mark at ascentium.co.uk
Sat Aug 14 18:52:26 UTC 2004
John,
If you are _really_ consider yourself a complete beginner, then I would
recommend "HTML for Dummies". I've used that book before to help non-IT
literate staff design web sites.
However, to get you started:
HTML is a standard for "marking up a document" to show some details of its
structure. The type of document that HTML does well is something called
"Hypertext", (the H in HTML stands for Hypertext) which is a way in which
documents can include links to other documents. If you've ever surfed the
web, then you understand what a link is - and what an HTML document can look
like.
In addition to containing information about links, HTML includes the ability
to define some things about formatting.
The big thing with HTML is that it defines things about bits of text, that
are relatively general. For example it can say that a particular word will
appear in bold. However, how that actually looks depends on what software
you are using to view the document, and what the capabilities of the machine
you're using are. For example, on a whizzy new Apple Mac, bold text will
look like something lovingly crafted by generations of design-gurus....
wheras on a text-to-speech terminal for a blind use, it won't even have a
visual representation - it might just be read more loudly.
When HTML was originally written, it included a set of basic instructions -
how to make stuff bold, how to make it italic, and so on - but as time went
by, people, particularly people from a design background weren't happy with
this, and demanded more control over exactly how things looked. There
emerged a standards war in which Microsoft and Netscape (the two largest
companies producing HTML-viewing software) added their own extensions to
these standards, in a way that caused problems... Microsoft and Netscape
browsers would interpret and show things in different ways.
To solve that problem, and to try to resolve the conflict between
"ultra-design-concious" authors and users with wide ranges of hardware, a
group called the World Wide Web Consortium (W3C) came up a with a standard,
called StyleSheets, to try to provide a general method of controlling
formatting that allowed more control than the original HTML had, but also
respected the needs of the sight-impaired person and the older text
displays.
In early stylesheets, the "Style" information was contained in the HTML
document - the document started with a section that read "you no longer get
to choose what bold means - bold means you use this font size, and this
colour, and one of these fonts."
It was quickly worked out that, in the average web site, pretty much all the
pages would have the same "styles", so for efficiency, theese "styles" were
moved out into a separate file, and rather than pages of stuff defining what
bold looked like, HTML documents were encouraged to have a line that read
"go and look on this web page to work out what styles I want to use."
These "cascading" style sheets, or CSS pages, because best practice, and
modern websites use them.
The CSS standard also said that a lot of the tricks that web designers had
been using (such as using tables as layout tools) were bad practice, and
came up with a different way of handling layout data.
Then, along came XML. XML is a general way, not to define a document, but to
define the way in which a document is interpreted. XML documents look
vaguely like HTML documents, but where HTML documents have tags that mean
things like "this bit in bold", then XML documents have tags that mean
things like "This is the price per item" (in an XML document about
accounting), or "This is version 3.2 of this document" (in an XML document
about version controlling.)
The bit of XML that said how to interpret a document - whether it was an
accounts record, or a document control record - was initially called a Data
Type Definition (DTD.) After a bit of experience in the field, the way in
which DTDs were written was tweaked to solve the problems people had
encountered, and a new generation, called XML Schemas was introduced, again
with the backing of W3C.
At this point, people started asking "isn't there a way in which HTML and
XML can merge".... which turned out to be asking "can't we say that HTML is,
itself, an XML Schema".
It turned out, on looking carefully, that the answer was "Almost". The
(then) current versions of HTML, sadly, broke a few of the XML "rules" about
how Schemas had to act.
The solution was to say that the "next" version of HTML would obey these
rules, and XHTML was born....
Now to turn to some examples:
If you look at one of my sites - www.yourpropertyexpert.com, and look at the
page SOURCE, rather than how your browser displays it, you'll see a number
of things:
The first line:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">.... says that this HTML
document is in the XHTML 1.0 Strict Schema, rather than any other version of
HTML.
The line:
<link href="public.css" rel="stylesheet" type="text/css"/>
.... says that, if you've got a suitably capable machine which can interpret
formatting information, go and look on my server for a file called
"public.css" which contains definitions of the style sheets the various
pages in the site will all use to enforce a common look and feel.
The file:
www.yourpropertyexpert.com\public.css
Actually contains all that "style" information, such as the colours of the
fonts used in the various sections....
Hope this helps,
Regards,
Mark
----- Original Message -----
From: "John D." <big-john at dsl.pipex.com>
To: "LUG email list for the Sussex Counties" <sussex at mailman.lug.org.uk>
Sent: Saturday, August 14, 2004 7:27 PM
Subject: [Sussex] 2 questions (probably stupid)
> Hi list,
>
> The first Q, is that I want to have a go at building a website. Fine.
> Problem is, that the more I read about how this is actually done, then
> the greater the confusion.
>
> So could anyone suggest a book that I could lay my hands on that can
> explain how this is done - preferably in "normal" english, as part of my
> confusion stems from not really understanding what is being explain by
> virtue of "techie speak"
>
> Something that explains html, xhtml and css would be excellent, but as
> the list of stuff available via amazon run's to some 90 different pub's,
> a personal recommendation would be brilliant.
>
> Second Q, is that having got my head round evolution 1.4, how in hell's
> name do I empty the "trash" folder. I (as I suspect you do) get a
> variety of spam, which just get's the trash can treatment - though it
> now appear's that my "trash" has over a 1000 item's in it. I'm unable to
> locate a delete facility, or preferably a bulk delete facility - any
> pointers greatly appreciated.
>
> regards
>
> John D.
>
>
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> Sussex at mailman.lug.org.uk
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>
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