Wednesday, 21 August 2013

Elements & Semantics - Part 3(HTML5)

HTML5 Structural Elements

HTML5 provides a handful of new elements, all of which are focused around improving semantics. Before, if you wanted to declare a block level section of a page you were likely to use a div. With HTML5 you have a handful of new block level elements that allow you to write more semantic code.
HTML5 Document Structure
Fig. 2.01The new HTML5 structural elements outline.


The header, just as it sounds, is used to identify the heading of a page, article, section, or other segment of a page. In general, a header may include a heading, introduction text, or navigation. You can use more than one header on a page. Depending on the website, you will ideally include a header at the beginning of the page. Additionally, a headermay reappear as the header of an article or section as necessary.
  1. <header>...</header>

Clarification on the header Element

The header element should not be confused with the head or headings, h1 through h6.
The header element is a structural element that outlines a heading on a page, of which falls within the bodyelement on a page. The head element is not displayed on the page and is used to outline meta data, the document title, and links to external files.
Headings, h1 through h6, are used to represent multiple levels of text headings throughout a page.


The nav is a block level element used to denote a section of major navigational links on a page. Not all links should be wrapped within a nav element. The nav should be reserved for primary navigation sections including universal navigation, a table of contents, breadcrumbs, previous/next links, or other noteworthy groups of links.
Most commonly links included within the nav element will link to other parts of the same website or web page. Miscellaneous one off links should not be wrapped within the nav element, and should only use the a element.
  1. <nav>
  2. <ul>
  3. <li><a href="#">...</a></li>
  4. <li><a href="#">...</a></li>
  5. </ul>
  6. </nav>


The article block level element is very similar to that of a div or section however it is specifically defined as an element which should include independent, self-contained content that may be independently distributable or reusable. Most often article will fall within blogs and other publishing websites as a block of published content. When deciding to use the article element determine if the content within the element could be replicated elsewhere without any confusion. The content within the article alone must make sense, and be able to be distrbuted elsewhere, such as within an RSS feed.
  1. <article>...</article>


section is more likely to get confused with a div than an article. As a block level element, section is defined to represent a generic document or application section. Where a section differentiates itself from a div is that asection is not to be used as a convenience for styling or scripting purposes.
That said – you can apply styles to a section however you shouldn’t be using a section aimlessly with the sole purpose of adding styles. Reserve the section element for large parts of a page worthy of the element.
  1. <section>...</section>

Deciding When to Use a section or div

The best way to determine when to use a section versus a div is to look at the actual content at hand. If the block of content could exist as a record within a database and isn’t explicitly needed as a CSS styling hook then the section element is most applicable. Sections should be used to break a page up, providing a natural hierarchy, and most commonly will have a proper heading.
div on the other hand may be used to specifically tie styles to a block of content. As an example, if a couple paragraphs need to stand out above the rest of the content on a page they should be wrapped in a div. Thatdiv then may have the proper styles applied to it, perhaps a background, border, or the alike.


To accompany the header and footer elements there is also the aside block level element. An aside defines content related to the document or section surrounding it. As with header and footer elements, the aside can be used multiple times per page, so long as each use is practical.
Please keep in mind that the aside is a block level element, in which it will appear on a new line and occupy the full width of the page or any container. If you would like to get the aside to appear to the right or left of a block of content you will need to float the aside element. Don’t worry about floats right now, we will learn about floating and positioning content in an upcoming lesson.
  1. <aside>...</aside>


The footer is identical to that of the header however for the bottom of a page, article, section, or other segment of a page. A footer should not stem away from the document or section at hand and its context should include relative information.
  1. <footer>...</footer>

D.R.Y. – Don’t Repeat Yourself

One principle of development is D.R.Y., also known as don’t repeat yourself. Within CSS this principle can speak volumes as it is easy to continually write the same styles over and over again. Don’t. CSS was designed in a way to allow you to cascade styles and use classes so that you easily apply and inherent styles. The end goal is to write clean and light code, of which is semantic and easily managed.