How to code HTML | skybert.net

How to code HTML


Introduction

"Everyone" believes they know how to write HTML code. People consider it as THE basic skill in the computer world, and they are right, HTML is definitely one of the basic, fundamentals of computer science and is not hard at all once you get the grips with it.

Even so, there's extremely rare to come across a site that is properly written. Most people don't actually know how to do HTML properly, the right way. It is only the grace of web browsers, and especially the blind stupidity of kindness from Microsoft Internet Explorer, that make people's pages work at all on the world wide web.

Worse is, that when looking through a dusin of HTML coding books, there's not one that teaches it properly. It's just "quick and dirty" and low level Mickey Mouse code that is taught, no one seems to take HTML seriously.

This is not done any better by the vast majority of WYSIWYG programs that produces crappy code, such as Frontpage, Dreamweaver and HotMetal. A lot of people say that these produce "not bade code at all", especially Dreamweaver gets a lot of praise in this respect. But, I would argue that it's only people that don't know how to do it the proper way that use these programs. Once you're comfertable with the robes of HTML and CSS, it's faster, a lot more acurate and better craftmanship alltogether to code the pages yourself.

I will on this page teach you how to do HTML properly, how it was meant to be and how it should be. If you write proper HTML code, you will have greater control and your page stand a better chance of being displayed identically on all browsers. So, if you want to take "the path less travelled by", read on dear traveller.

The Road Less Travelled By

What HTML is

so you know what you're talking about

How HTML elements work together,

so you know what you're doing.

How to write your code,

so it looks like you know what you're doing

How to validate your code,

so you can prove you know what you're doing.

What HTML is

HTML is short for HyperText Markup Language and is a language for describing how documents should be presented. It is not a programming language as some people mistakenly call it, but a language you use to tell how you want your data to be displayed, either on screen, paper, voice or blind displays.

W3C

It was first presented by Tim Berners Lee and is now maintained by the World Wide Web Consortium. This is an independent, non profit organ that sets the standards on the web, much like a goverment in a country.

There are different versions of HTML, the ones you should know about is HTML 3.2, HTML 4.0, HTML 4.01 and XHTML 1.0.

The specifications are written as a DTD, a Document Type Definition, which is a document written in SGML, another language, describing what is allowed and what is not allowed in the different HTML versions. The DTD is the ultimate reference when coding (X)HTML.

Version 3.2 is old style, which should be avoided as newer offer better ways of doing things. 3.2 is very forgiving and "nice". It combines presentation and structure, meaning it has elements and arguments for telling how you want things to "look", including <font> and <center>.

html validated

It was then decided that HTML should only be used to describe the structure of the document and that all formatting/visual information should be given elsewhere, for example with the use of a Cascading Style Sheet . HTML 4.0 was released with this given in its definition < and

were deprecated and not allowed to be used anymore. Version 4.01 quickly followed, and was more or less a rewrite of the 4.0 with the inclusion of the "name" attribute, needed for the highly popular "image swap" JavaScript and various CGI interfaces.

xhtml validated

As the XML was introduced as a generic language of defining data, XHTML was introduced to give an HTML version of XML. Basically it is HTML 4.01 but stricter. Following the XML recommendation, all elements must be lower case, "name" is not allowed as an attribute and empty elements must be closed. I will use XHTML in my examples in this tutorial.

To show the world ( and the validator ) that you know which HTML specification you are coding after, you must insert a DOCTYPE header in your HTML file. This is a line of code that says which DTD your writing after, and where it can be found. I use this header for my XHTML files, remember to that this must be on the first line, otherwise it will just confuse the validator or browser.

<!DOCTYPE html PUBLIC
"-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"
>

You can find the approperiate DOCTYPE headers for the other versions of HTML at the World Wide Web Consortium website.

Now you know more about HTML than most web designers and web programmers. Seriously.

How HTML elements work together

HTML consists of a number of elements which each have their properties and uses.

The html, body and head

The "biggest" element is the html element. It can hold two, and only two, other elements, namely head and body. An HTML document needs a body, but not a head. If you do have a head, you need a title inside the head.

<If you have a head you must have a title

Apart from these three, special elements ( which to a great extent are block level elements ), there are two kinds of elements, inline elements and block level elements.

Block level elements

Block level elements have the thing in common that they can contain other elements. They can hold both inline elements and other block level elements.

The commonly used block level elements are p, div, form, pre, tr and tablefont and center are both block level elments, but are deprecated in HTML version 4.0 and should therefore not be used ).

<p>
  The paragraph, <em>p</em>, is a block level element.
</p>

Inline elements

These elements cannot hold other elements. They also must reside within a block level element. For example, an anchor/web link cannot exist on its own, but need a block level element "to take care of it". For example a paragraph.

<p>
  <a href="">My web link is an inline element</a>
  and resides within a block level element, namely a
  paragraph.
</p>

The commonly used inline elements are img, a, input, span, em, strong, link, br, meta, title, script, th, td, script, code and h1/em> ( b, i, u are all inline elements, but deprecated in HTML version 4.0 and should therefore not be used ).

You shouldn't really use the linebreak element, br, as it controls the appearance of the document. Again, everything ( as far as possible ) about the looks of your page should be given in a stylesheet.

Attributes

Attributes are the things written inside the tags of the start element after the element name itself. The attribute consist of two parts, the attribute name and the attribute value. The attribute value should be given with double quotes around it.

<div attribute_name="attribute_value" />

The reason why you should not use single quotes is that JavaScript instructions may be given in an attribute, and these may use single quotes for strings without messing up your markup and confusing the browser.

<input
  id="my_button_id"
  type="button"
  onclick="javascriptFunction( 'You clicked a button' );"
/>

Writing Your Code

How you write your code is entirely up to you, but I have some strong recommendations on how to do it for reasons which I will make clear below.

Indentation size

I think 3 space indentiation is right, whereas others think 2 is enough and other again pick 8 spaces for each indentation. The important thing is that you are consistent.

Inline and block level elements

Inline elements should be indented inside block level elements. Inline elements are affected by the block level element(s) which they reside within. For example will a link inherit the colours and font from the block it is within. By indenting the inline elements inside block level elements, you keep a clear overview on how elements affect eachother. Block level elements can also influence other block level elements that reside within, so everything should be indented.

<div>
  <a href="">An anchor/link is an inline element</a>
  <div>
    This div is inside the other div, and is therefore
    indented like this.
  </div>
</div>

Indenting like this, with open element and corresponding close element over one another also makes it a lot easier to see if you've closed all your elements.

By being consequent with your indentation, it is at all times easy to see which elements that contain which. For example, the head and body elements should be indented under the html element, as this is the mother these.

Attributes

To keep a clear and concise style, it is important to have everything on one line, including the indentaiton. This can be difficult if you have attributes that will make the total space the element takes exceed the line width in your editor. Therefore, I indent the atttributes under one another with the closing tag under the opening one. Once you start with this, you will gain a far greater control over complex elements, and it will also be benefitial for clearity when coding XML.

<img src="graphics/my_picture.png"
  alt="My picture text"
  id="my_picture_id"
/>

As you can see, I keep the element name clear, and indent all attributes according to the first attribute name.

Validating Your Code

xhtml validated

To ensure that you have done everything correctly, there's two things you should do. Firstly, go to the World Wide Web Consortium validator and let it run through your page. It will list any error it finds, if any alongside with explenations for why this is an error. Don't give up until there's no errors left, and it says "validated!".

You can then put a validation icon on your page to tell the world that you:

The other thing you should do, is to read through the whole HTML recommendation at World Wide Web Consortium to ensure that you have understood everything. Just because your site validates doesn't mean that you have done everything correctly, it's just likely :-)

But seriosuly, I strongly believe that you are able to start walking "the road less travelled by" coding HTML the proper just after reading this article. Read the above document at W3C only if you feel you want more in-depth and thorough discussion on the subject. Also, refer to W3C to find the full HTML specifications and DTD.

Happy coding!


Licensed under CC BY Creative Commons License ~ gmail torstein.k.johansen @ gmail ~ twitter @torsteinkrause ~