Monday, 2 January 2012

HTML Forms and Input

HTML Forms

HTML forms are used to pass data to a server.
A form can contain input elements like text fields, checkboxes, radio-buttons, submit buttons and more. A form can also contain select lists, textarea, fieldset, legend, and label elements.
The <form> tag is used to create an HTML form:

<form>
.
input elements
.
</form>

HTML Forms - The Input Element

The most important form element is the input element.
The input element is used to select user information.
An input element can vary in many ways, depending on the type attribute. An input element can be of type text field, checkbox, password, radio button, submit button, and more.
The most used input types are described below.

Text Fields

<input type="text" /> defines a one-line input field that a user can enter text into:

<form>
First name: <input type="text" name="firstname" /><br />
Last name: <input type="text" name="lastname" />
</form>

How the HTML code above looks in a browser:
Note: The form itself is not visible. Also note that the default width of a text field is 20 characters.

Password Field

<input type="password" /> defines a password field:

<form>
Password: <input type="password" name="pwd" />
</form>

How the HTML code above looks in a browser:
Note: The characters in a password field are masked (shown as asterisks or circles).

Radio Buttons

<input type="radio" /> defines a radio button. Radio buttons let a user select ONLY ONE of a limited number of choices:

<form>
<input type="radio" name="sex" value="male" /> Male<br />
<input type="radio" name="sex" value="female" /> Female
</form>

How the HTML code above looks in a browser:

Checkboxes

<input type="checkbox" /> defines a checkbox. Checkboxes let a user select ONE or MORE options of a limited number of choices.

How the HTML code above looks in a browser:

Submit Button

<input type="submit" /> defines a submit button.
A submit button is used to send form data to a server. The data is sent to the page specified in the form's action attribute. The file defined in the action attribute usually does something with the received input:

<form name="input" action="html_form_action.asp" method="get">
Username: <input type="text" name="user" />
<input type="submit" value="Submit" />
</form>

How the HTML code above looks in a browser:
If you type some characters in the text field above, and click the "Submit" button, the browser will send your input to a page called "html_form_action.asp". The page will show you the received input.

HTML Links

HTML Hyperlinks (Links)

A hyperlink (or link) is a word, group of words, or image that you can click on to jump to a new document or a new section within the current document.
When you move the cursor over a link in a Web page, the arrow will turn into a little hand.
Links are specified in HTML using the <a> tag.
The <a> tag can be used in two ways:

To create a link to another document, by using the href attribute
To create a bookmark inside a document, by using the name attribute

HTML Link Syntax

The HTML code for a link is simple. It looks like this:

The href attribute specifies the destination of a link.

Example

HTML Links - The target Attribute

The target attribute specifies where to open the linked document.
The example below will open the linked document in a new browser window or a new tab:

Example

<a href="http://patel-software.blogspot.com">Patel free software download</a>

Try it yourself »

HTML Links - The name Attribute

The name attribute specifies the name of an anchor.
The name attribute is used to create a bookmark inside an HTML document.
Note: The upcoming HTML5 standard suggests using the id attribute instead of the name attribute for specifying the name of an anchor. Using the id attribute actually works also for HTML4 in all modern browsers.
Bookmarks are not displayed in any special way. They are invisible to the reader.

Wednesday, 14 December 2011

HTML Styles - CSS

CSS is used to style HTML elements.

Look! Styles and colors

This text is in Verdana and red

This text is in Times and blue

This text is 30 pixels high

Try it yourself

Styling HTML with CSS

CSS was introduced together with HTML 4, to provide a better way to style HTML elements.
CSS can be added to HTML in the following ways:

in Cascading Style Sheet files (CSS files)
in the <style> element in the HTML head section
in the style attribute in single HTML elements

Using the HTML Style Attribute

It is time consuming and not very practical to style HTML elements using the style attribute.
The preferred way to add CSS to HTML, is to put CSS syntax in separate CSS files.
However, in this HTML tutorial we will introduce you to CSS using the style attribute. This is done to simplify the examples. It also makes it easier for you to edit the code and try it yourself.
You can learn everything about CSS in our CSS Tutorial.

HTML Style Example - Background Color

The background-color property defines the background color for an element:

Example

<html>

<body style="background-color:yellow;">
<h2 style="background-color:red;">This is a heading</h2>
<p style="background-color:green;">This is a paragraph.</p>
</body>

</html>

Try it yourself »

The background-color property makes the "old" bgcolor attribute obsolete.
Try it yourself: Background color the old way

HTML Style Example - Font, Color and Size

The font-family, color, and font-size properties defines the font, color, and size of the text in an element:

Example

<html>

<body>
<h1 style="font-family:verdana;">A heading</h1>
<p style="font-family:arial;color:red;font-size:20px;">A paragraph.</p>
</body>

</html>

Try it yourself »

The font-family, color, and font-size properties make the old <font> tag obsolete.

HTML Style Example - Text Alignment

The text-align property specifies the horizontal alignment of text in an element:

Example

<html>

<body>
<h1 style="text-align:center;">Center-aligned heading</h1>
<p>This is a paragraph.</p>
</body>

</html>

Try it yourself »

The text-align property makes the old <center> tag obsolete.
Try it yourself: Centered heading the old way

Deprecated Tags and Attributes

In HTML 4, several tags and attributes were deprecated. Deprecated means that they will not be supported in future versions of HTML.
Remark

The message is clear: Avoid using deprecated tags and attributes!
These tags and attributes should be avoided:

Tags	Description
<center>	Deprecated. Defines centered content
<font> and <basefont>	Deprecated. Defines HTML fonts
<s> and <strike>	Deprecated. Defines strikethrough text
<u>	Deprecated. Defines underlined text
Attributes	Description
align	Deprecated. Defines the alignment of text
bgcolor	Deprecated. Defines the background color
color	Deprecated. Defines the text color

For all of the above: Use styles instead!

HTML Fonts

The HTML <font> Tag Should NOT be Used

The <font> tag is deprecated in HTML 4, and removed from HTML5.
The World Wide Web Consortium (W3C) has removed the <font> tag from its recommendations.
In HTML 4, style sheets (CSS) should be used to define the layout and display properties for many HTML elements.
The example below shows how the HTML could look by using the <font> tag:

Example

<p>
<font size="5" face="arial" color="red">
This paragraph is in Arial, size 5, and in red text color.
</font>
</p>

<p>
<font size="3" face="verdana" color="blue">
This paragraph is in Verdana, size 3, and in blue text color.
</font>
</p>

HTML Text Formatting

This text is bold

This text is big

This text is italic

This is computer output

This is_subscript and ^superscript

Try it yourself »

HTML Formatting Tags

HTML uses tags like <b> and <i> for formatting output, like bold or italic text.
These HTML tags are called formatting tags (look at the bottom of this page for a complete reference).

	Often <strong> renders as <b>, and <em> renders as <i>. However, there is a difference in the meaning of these tags: <b> or <i> defines bold or italic text only. <strong> or <em> means that you want the text to be rendered in a way that the user understands as "important". Today, all major browsers render strong as bold and em as italics. However, if a browser one day wants to make a text highlighted with the strong feature, it might be cursive for example and not bold!

Often <strong> renders as <b>, and <em> renders as <i>.

However, there is a difference in the meaning of these tags:

<b> or <i> defines bold or italic text only.

<strong> or <em> means that you want the text to be rendered in a way that the user understands as "important". Today, all major browsers render strong as bold and em as italics. However, if a browser one day wants to make a text highlighted with the strong feature, it might be cursive for example and not bold!

HTML Text Formatting Tags

Tag	Description
<b>	Defines bold text
<big>	Defines big text
<em>	Defines emphasized text
<i>	Defines italic text
<small>	Defines small text
<strong>	Defines strong text
<sub>	Defines subscripted text
<sup>	Defines superscripted text
<ins>	Defines inserted text
<del>	Defines deleted text

HTML "Computer Output" Tags

Tag	Description
<code>	Defines computer code text
<kbd>	Defines keyboard text
<samp>	Defines sample computer code
<tt>	Defines teletype text
<var>	Defines a variable
<pre>	Defines preformatted text

HTML Citations, Quotations, and Definition Tags

Tag	Description
<abbr>	Defines an abbreviation
<acronym>	Defines an acronym
<address>	Defines contact information for the author/owner of a document
<bdo>	Defines the text direction
<blockquote>	Defines a long quotation
<q>	Defines a short quotation
<cite>	Defines a citation
<dfn>	Defines a definition term

Tuesday, 13 December 2011

HTML VIDEO

Monday, 12 December 2011

HTML Paragraphs

Paragraphs are defined with the <p> tag.

Example

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

Try it yourself »

Note: Browsers automatically add an empty line before and after a paragraph.

Don't Forget the End Tag

Most browsers will display HTML correctly even if you forget the end tag:

Example

<p>This is a paragraph
<p>This is another paragraph

Try it yourself »

The example above will work in most browsers, but don't rely on it. Forgetting the end tag can produce unexpected results or errors.
Note: Future version of HTML will not allow you to skip end tags.

HTML Line Breaks

Use the <br /> tag if you want a line break (a new line) without starting a new paragraph:

Example

<p>This is<br />a para<br />graph with line breaks</p>

Try it yourself »

The <br /> element is an empty HTML element. It has no end tag.

<br> or <br />

In XHTML, XML, elements with no end tag (closing tag) are not allowed.
Even if <br> works in all browsers, writing <br /> instead works better in XHTML and XML applications.

HTML Output - Useful Tips

You cannot be sure how HTML will be displayed. Large or small screens, and resized windows will create different results.
With HTML, you cannot change the output by adding extra spaces or extra lines in your HTML code.
The browser will remove extra spaces and extra lines when the page is displayed. Any number of lines count as one line, and any number of spaces count as one space.
Try it yourself
(The example demonstrates some HTML formatting problems)

HTML Tag Reference

W3Schools' tag reference contains additional information about HTML elements and their attributes.

Tag	Description
<p>	Defines a paragraph
<br />	Inserts a single line break