Attributes provide additional information about HTML elements.

HTML elements can have attributes
Attributes provide additional information about an element
Attributes are always specified in the start tag
Attributes come in name/value pairs like: name="value"

Attribute Example:

HTML links are defined with the <a> tag. The link address is specified in the href attribute:

Example

<a href="http://www.creativedesignbest.blogspot.com">This is a link</a>

Always Quote Attribute Values:

Attribute values should always be enclosed in quotes.

Double style quotes are the most common, but single style quotes are also allowed.

HTML Tip: Use Lowercase Attributes:

Attribute names and attribute values are case-insensitive.

However, the World Wide Web Consortium (W3C) recommends lowercase attributes/attribute values in their HTML 4 recommendation.

Newer versions of (X)HTML will demand lowercase attributes.

HTML Attributes Reference:

Below is a list of some attributes that can be used on any HTML element:

Attribute Description

class Specifies one or more classnames for an element (refers to a class in a style sheet)

id Specifies a unique id for an element

style Specifies an inline CSS style for an element

title Specifies extra information about an element (displayed as a tool tip)

HTML Example

<!DOCTYPE html>
<html>
<body>

<h1>My First Heading</h1>

<p>My first paragraph.</p>

</body>
</html>

Example Explained

The DOCTYPE declaration defines the document type
The text between <html> and </html> describes the web page
The text between <body> and </body> is the visible page content
The text between <h1> and </h1> is displayed as a heading
The text between <p> and </p> is displayed as a paragraph

Note: The <!DOCTYPE html> declaration is the doctype for HTML5.

What is HTML?

HTML is a language for describing web pages.

HTML stands for Hyper Text Markup Language
HTML is a markup language
A markup language is a set of markup tags
The tags describe document content
HTML documents contain HTML tags and plain text
HTML documents are also called web pages

HTML Tags:

HTML markup tags are usually called HTML tags

HTML tags are keywords (tag names) surrounded by angle brackets like <html>
HTML tags normally come in pairs like <b> and </b>
The first tag in a pair is the start tag, the second tag is the end tag
The end tag is written like the start tag, with a forward slash before the tag name
Start and end tags are also called opening tags and closing tags

<tagname>content</tagname>

HTML Elements:

"HTML tags" and "HTML elements" are often used to describe the same thing.

But strictly speaking, an HTML element is everything between the start tag and the end tag, including the tags:

HTML Element:

<p>This is a paragraph.</p>

Web Browsers:

The purpose of a web browser (such as Google Chrome, Internet Explorer, Firefox, Safari) is to read HTML documents and display them as web pages.

The browser does not display the HTML tags, but uses the tags to determine how the content of the HTML page is to be presented/displayed to the user:

HTML Page Structure

Below is a visualization of an HTML page structure:

<html>

<body>

<h1>This a heading</h1>

<p>This is a paragraph.</p>

<p>This is another paragraph.</p>

</body>

</html>

Attributes are another important part of HTML markup. An attribute is used to define the characteristics of an element and is placed inside the element's opening tag. All attributes are made up of two parts: a name and a value:

· The name is the property you want to set. For example, the <font> element in the example carries an attribute whose name is face, which you can use to indicate which typeface you want the text to appear in.

· The value is what you want the value of the property to be. The first example was supposed to use the Arial typeface, so the value of the face attribute is Arial.

The value of the attribute should be put in double quotation marks, and is separated from the name by the equals sign. You can see that a color for the text has been specified as well as the typeface in this <font> element:

<font face="arial" color="#CC0000">

Many HTML tags have a unique set of their own attributes. These will be discussed as each tag is introduced throughout the tutorial. Right now we want to focus on a set of generic attributes that can be used with just about every HTML Tag in existence.

Core Attributes:

The four core attributes that can be used on the majority of HTML elements (although not all) are:

id
title
class
style

The id Attribute:

The id attribute can be used to uniquely identify any element within a page ( or style sheet ). There are two primary reasons that you might want to use an id attribute on an element:

· If an element carries an id attribute as a unique identifier it is possible to identify just that element and its content.

· If you have two elements of the same name within a Web page (or style sheet), you can use the id attribute to distinguish between elements that have the same name.

We will discuss style sheet in separate tutorial. For now, the id attribute could be used to distinguish between two paragraph elements, like so:

<p id="html">This para explains what is HTML</p>
<p id="css">This para explains what is Casecading Style Sheet</p>

Note that there are some special rules for the value of the id attribute, it must:

· Begin with a letter (A.Z or a.z) and can then be followed by any number of letters, digits (0.9), hyphens, underscores, colons, and periods.

· Remain unique within that document; no two attributes may have the same value within that HTML document.

The title Attribute:

The title attribute gives a suggested title for the element. They syntax for the title attribute is similar as explained for id attribute:

The behavior of this attribute will depend upon the element that carries it, although it is often displayed as a tooltip or while the element is loading.

For example:

<h4 title="Hello HTML!">Titled Heading Tag Example</h4>

Above code will generate following result:

Titled Heading Tag Example

Now try to bring your cursor over "Titled Heading Tag Example" and see the result.

The class Attribute:

The class attribute is used to associate an element with a style sheet, and specifies the class of element. You learn more about the use of the class attribute when you will learn Casecading Style Sheet (CSS). So for now you can avoid it.

The value of the attribute may also be a space-separated list of class names. For example:

class="className1 className2 className3"

HTML name Attribute:

1.<input type="text" name="TextField" />

The style Attribute:

The style attribute allows you to specify CSS rules within the element. For example:

<p style="font-family:arial; color:#FF0000;">Some text...</p>

HTML align Attribute:

1.<h2 align="center">Centered Heading</h2>

Cent er ed Headi ng

1.<h2 align="left">Left aligned heading</h2>

2.<h2 align="center">Centered Heading</h2>

3.<h2 align="right">Right aligned heading</h2>

Lef t al i gned headi ng

Cent er ed headi ng

Right aligned heading:

Internationalization Attributes:

There are three internationalization attributes, which are available to most (although not all) XHTML elements.

dir
lang
xml:lang

The dir Attribute:

The dir attribute allows you to indicate to the browser the direction in which the text should flow.The dir attribute can take one of two values, as you can see in the table that follows:

Value	Meaning
ltr	Left to right (the default value)
rtl	Right to left (for languages such as Hebrew or Arabic that are read right to left)

Example:

<html dir=rtl>

<head>

<title>Display Directions</title>

</head>

<body>

This is how IE 5 renders right-to-left directed text.

</body>

</html>

When dir attribute is used within the <html> tag, it determines how text will be presented within the entire document. When used within another tag, it controls the text's direction for just the content of that tag.

The lang Attribute:

The lang attribute allows you to indicate the main language used in a document, but this attribute was kept in HTML only for backwards compatibility with earlier versions of HTML. This attribute has been replaced by the xml:lang attribute in new XHTML documents.

When included within the <html> tag, the lang attribute specifies the language you've generally used within the document. When used within other tags, the lang attribute specifies the language you used within that tag's content. Ideally, the browser will use lang to better render the text for the user.

Example:

<html lang=en>

<head>

<title>English Language Page</title>

</head>

<body>

This page is using English Language

</body>

</html>

The xml:lang Attribute:

The xml:lang attribute is the XHTML replacement for the lang attribute. The value of the xml:langattribute should be an ISO-639 country code as mentioned in previous section.

Generic Attributes:

Here's a table of some other attributes that are readily usable with many of HTML's tags.

Attribute	Options	Function
align	right, left, center	Horizontally aligns tags
valign	top, middle, bottom	Vertically aligns tags within an HTML element.
bgcolor	numeric, hexidecimal, RGB values	Places a background color behind an element
background	URL	Places an background image behind an element
id	User Defined	Names an element for use with Cascading Style Sheets.
class	User Defined	Classifies an element for use with Cascading Style Sheets.
width	Numeric Value	Specifies the width of tables, images, or table cells.
height	Numeric Value	Specifies the height of tables, images, or table cells.
title	User Defined	"Pop-up" title for your elements.

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Monday, May 5, 2014

HTML Attributes