What are the 6 design principles that HTML5 needs to follow?-H5 Tutorial-php.cn

What are the 6 design principles that HTML5 needs to follow?

青灯夜游

Release： 2018-09-10 17:46:17

Original

1947 people have browsed it

This chapter will introduce the 6 design principles that HTML5 needs to follow. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to you.

Principle 1: Avoid unnecessary complexity

html4

<!DOCTYPE html PUBLIC "-//W3C/DTD HTML 4.01//EN" " 
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">

Copy after login

html5

<!DOCTYPE html>
<meta charset="utf-8">

Copy after login

Principle 2: Support existing content

In the following four pieces of code, only the first paragraph is correct in xhtml; in html5, all of them are Correct

<img src="foo" alt="bar" />  
<p class="foo">Hello world</p>

Copy after login

<img src="foo" alt="bar">  
<p class="foo">Hello world

Copy after login

<IMG SRC="foo" ALT="bar">  
<P CLASS="foo">Hello world</P>

Copy after login

<img src=foo alt=bar>  
<p class=foo>Hello world</p>

Copy after login

Principle 3: Solve real-life problems

In HTML4, even if two block-level elements have the same link address , must also be written separately, because inline elements cannot contain block-level elements

<h2><a href="/path/to/resource">Headline text</a></h2>
<p><a href="/path/to/resource">Paragraph text.</a></p>

Copy after login

And in html5, due to the use of the content model, elements can also contain block-level elements

<a href="/path/to/resource">  
    <h2>Headline text</h2>  
    <p>Paragraph text.</p>  
</a>

Copy after login

Principle 4: Seek truth and be pragmatic

html5 has added a number of new elements, including: section, article, aside and nav, which represent a new Content model - Partition content. People have been using divs to organize content on pages in the past, but like other similar elements, divs themselves have no semantics. But section, article, aside, and nav are actually telling you clearly that this section is like another document within the document. Any content located within these elements can have its own summary, its own title, its own footer.

Principle 5: Smooth degradation

When the browser encounters an unrecognized type value, it will interpret the value of type as text

input type="number"
input type="search"
input type="range"
input type="email"
input type="date"
input type="url"

Copy after login

Principle 6: End user first

In case of conflict, the end user takes priority, followed by the author, followed by the implementer, followed by the standard The framer, in the end, is the theoretical perfection.

The above is the detailed content of What are the 6 design principles that HTML5 needs to follow?. For more information, please follow other related articles on the PHP Chinese website!