Thursday, 20 December 2018

            Html basic knowledge continue 2nd part . Start
A webpage can contain various links that take you directly to other pages and even specific parts of a given page. These links are known as hyperlinks.
Hyperlinks allow visitors to navigate between Web sites by clicking on words, phrases, and images. Thus you can create hyperlinks using text or images available on a webpage.
Note − I recommend you to go through a short tutorial on Understanding URL

Linking Documents

A link is specified using HTML tag <a>. This tag is called anchor tag and anything between the opening <a> tag and the closing </a> tag becomes part of the link and a user can click that part to reach to the linked document. Following is the simple syntax to use <a> tag.
<a href = "Document URL" ... attributes-list>Link Text</a>

Example

Let's try following example which links http://www.tutorialspoint.com at your page −
 Live Demo
<!DOCTYPE html>
<html>
   
   <head>
      <title>Hyperlink Example</title>
   </head>
 
   <body>
      <p>Click following link</p>
      <a href = "https://www.tutorialspoint.com" target = "_self">Tutorials Point</a>
   </body>
 
</html>
This will produce the following result, where you can click on the link generated to reach to the home page of Tutorials Point (in this example).

The target Attribute

We have used target attribute in our previous example. This attribute is used to specify the location where linked document is opened. Following are the possible options −
Sr.NoOption & Description
1
_blank
Opens the linked document in a new window or tab.
2
_self
Opens the linked document in the same frame.
3
_parent
Opens the linked document in the parent frame.
4
_top
Opens the linked document in the full body of the window.
5
targetframe
Opens the linked document in a named targetframe.

Example

Try following example to understand basic difference in few options given for target attribute.
 Live Demo
<!DOCTYPE html>
<html>

   <head>
      <title>Hyperlink Example</title>
      <base href = "https://www.tutorialspoint.com/">
   </head>
 
   <body>
      <p>Click any of the following links</p>
      <a href = "/html/index.htm" target = "_blank">Opens in New</a> |
      <a href = "/html/index.htm" target = "_self">Opens in Self</a> |
      <a href = "/html/index.htm" target = "_parent">Opens in Parent</a> |
      <a href = "/html/index.htm" target = "_top">Opens in Body</a>
   </body>

</html>
This will produce the following result, where you can click on different links to understand the difference between various options given for target attribute.

Use of Base Path

When you link HTML documents related to the same website, it is not required to give a complete URL for every link. You can get rid of it if you use <base> tag in your HTML document header. This tag is used to give a base path for all the links. So your browser will concatenate given relative path to this base path and will make a complete URL.

Example

Following example makes use of <base> tag to specify base URL and later we can use relative path to all the links instead of giving complete URL for every link.
 Live Demo
<!DOCTYPE html>
<html>

   <head>
      <title>Hyperlink Example</title>
      <base href = "https://www.tutorialspoint.com/">
   </head>
 
   <body>
      <p>Click following link</p>
      <a href = "/html/index.htm" target = "_blank">HTML Tutorial</a>
   </body>
 
</html>
This will produce the following result, where you can click on the link generated HTML Tutorial to reach to the HTML tutorial.
Now given URL <a href = "/html/index.htm" is being considered as <ahref = "http://www.tutorialspoint.com/html/index.htm"

Linking to a Page Section

You can create a link to a particular section of a given webpage by using name attribute. This is a two-step process.
Note − The name attribute deprecated in HTML5. Do not use this attribute. Use id and titleattribute instead.
First create a link to the place where you want to reach with-in a webpage and name it using <a...> tag as follows −
<h1>HTML Text Links <a name = "top"></a></h1>
Second step is to create a hyperlink to link the document and place where you want to reach −
<a href = "/html/html_text_links.htm#top">Go to the Top</a>
This will produce following link, where you can click on the link generated Go to the Top to reach to the top of the HTML Text Link tutorial.
Go to the Top

Setting Link Colors

You can set colors of your links, active links and visited links using link, alink and vlink attributes of <body> tag.

Example

Save the following in test.htm and open it in any web browser to see how link, alink and vlinkattributes work.
 Live Demo
<!DOCTYPE html>
<html>
   
   <head>
      <title>Hyperlink Example</title>
      <base href = "https://www.tutorialspoint.com/">
   </head>
 
   <body alink = "#54A250" link = "#040404" vlink = "#F40633">
      <p>Click following link</p>
      <a href = "/html/index.htm" target = "_blank" >HTML Tutorial</a>
   </body>
   
</html>
This will produce the following result. Just check color of the link before clicking on it, next check its color when you activate it and when the link has been visited.

Download Links

You can create text link to make your PDF, or DOC or ZIP files downloadable. This is very simple; you just need to give complete URL of the downloadable file as follows −
 Live Demo
<!DOCTYPE html>
<html>

   <head>
      <title>Hyperlink Example</title>
   </head>
 
   <body>
      <a href = "https://www.tutorialspoint.com/page.pdf">Download PDF File</a>
   </body>
 
</html>
This will produce following link and will be used to download a file.

File Download Dialog Box

Sometimes it is desired that you want to give an option where a user will click a link and it will pop up a "File Download" box to the user instead of displaying actual content. This is very easy and can be achieved using an HTTP header in your HTTP response.
For example, if you want make a Filename file downloadable from a given link then its syntax will be as follows.
#!/usr/bin/perl

# Additional HTTP Header
print "Content-Type:application/octet-stream; name = \"FileName\"\r\n";
print "Content-Disposition:attachment; filename = \"FileName\"\r\n\n";

# Open the target file and list down its content as follows
open( FILE, "<FileName" );

while(read(FILE, $buffer, 100)){
   print("$buffer");
}
Note − For more detail on PERL CGI programs, go through tutorial PERL and CGI
We have seen how to create hypertext link using text and we also learnt how to use images in our webpages. Now, we will learn how to use images to create hyperlinks.

Example

It's simple to use an image as hyperlink. We just need to use an image inside hyperlink at the place of text as shown below −
 Live Demo
<!DOCTYPE html>
<html>

   <head>
      <title>Image Hyperlink Example</title>
   </head>
 
   <body>
      <p>Click following link</p>
      <a href = "https://www.tutorialspoint.com" target = "_self"> 
         <img src = "/images/logo.png" alt = "Tutorials Point" border = "0"/> 
      </a>
   </body>
 
</html>
This will produce the following result, where you can click on the images to reach to the home page of Tutorials Point.

This was the simplest way of creating hyperlinks using images. Next we will see how we can create Mouse-Sensitive Image Links.

Mouse-Sensitive Images

The HTML and XHTML standards provides a feature that lets you embed many different links inside a single image. You can create different links on the single image based on different coordinates available on the image. Once different links are attached to different coordinates, we can click different parts of the image to open target documents. Such mouse-sensitive images are known as image maps.
There are two ways to create image maps −
  • Server-side image maps − This is enabled by the ismap attribute of the <img> tag and requires access to a server and related image-map processing applications.
  • Client-side image maps − This is created with the usemap attribute of the <img> tag, along with corresponding <map> and <area> tags.

Server-Side Image Maps

Here you simply put your image inside a hyper link and use ismap attribute which makes it special image and when the user clicks some place within the image, the browser passes the coordinates of the mouse pointer along with the URL specified in the <a> tag to the web server. The server uses the mouse-pointer coordinates to determine which document to deliver back to the browser.
When ismap is used, the href attribute of the containing <a> tag must contain the URL of a server application like a cgi or PHP script etc. to process the incoming request based on the passed coordinates.
The coordinates of the mouse position are screen pixels counted from the upper-left corner of the image, beginning with (0,0). The coordinates, preceded by a question mark, are added to the end of the URL.
For example, if a user clicks 20 pixels over and 30 pixels down from the upper-left corner of the following image −
Which has been generated by the following code snippet −
 Live Demo
<!DOCTYPE html>
<html>

   <head>
      <title>ISMAP Hyperlink Example</title>
   </head>
 
   <body>
      <p>Click following link</p>
      
      <a href = "/cgi-bin/ismap.cgi" target = "_self"> 
         <img ismap src = "/images/logo.png" alt = "Tutorials Point" border = "0"/> 
      </a>
   </body>
 
</html>

Then the browser sends the following search parameters to the web server which can be processed by ismap.cgi script or map file and you can link whatever documents you like to these coordinates −
/cgi-bin/ismap.cgi?20,30
This way you can assign different links to different coordinates of the image and when those coordinates are clicked, you can open corresponding linked document. To learn more about ismap attribute, you can check How to use Image ismap?
Note − You will learn CGI programming when you will study Perl programming. You can write your script to process these passed coordinates using PHP or any other script as well. For now, let's concentrate on learning HTML and later you can revisit this section.

Client-Side Image Maps

Client side image maps are enabled by the usemapattribute of the <img /> tag and defined by special <map> and <area> extension tags.
The image that is going to form the map is inserted into the page using the <img /> tag as a normal image, except it carries an extra attribute called usemap. The value of the usemap attribute is the value which will be used in a <map> tag to link map and image tags. The <map> along with <area> tags define all the image coordinates and corresponding links.
The <area> tag inside the map tag, specifies the shape and the coordinates to define the boundaries of each clickable hotspot available on the image. Here's an example from the image map −
 Live Demo
<!DOCTYPE html>
<html>

   <head>
      <title>USEMAP Hyperlink Example</title>
   </head>
 
   <body>
      <p>Search and click the hotspot</p>
      <img src = /images/html.gif alt = "HTML Map" border = "0" usemap = "#html"/>
      <!-- Create  Mappings -->
      
      <map name = "html">
         <area shape = "circle" coords = "80,80,20" 
            href = "/css/index.htm" alt = "CSS Link" target = "_self" />
         
         <area shape = "rect" coords = "5,5,40,40" alt = "jQuery Link" 
            href = "/jquery/index.htm" target = "_self" />
      </map>
   </body>
   
</html>
This will produce the following result −

Coordinate System

The actual value of coords is totally dependent on the shape in question. Here is a summary, to be followed by detailed examples −
  • rect = x1 , y1 , x2 , y2
    x1 and y1 are the coordinates of the upper left corner of the rectangle; x2 and y2 are the coordinates of the lower right corner.
  • circle = xc , yc , radius
    xc and yc are the coordinates of the center of the circle, and radius is the circle's radius. A circle centered at 200,50 with a radius of 25 would have the attribute coords = "200,50,25"
  • poly = x1 , y1 , x2 , y2 , x3 , y3 , ... xn , yn
    The various x-y pairs define vertices (points) of the polygon, with a "line" being drawn from one point to the next point. A diamond-shaped polygon with its top point at 20,20 and 40 pixels across at its widest points would have the attribute coords = "20,20,40,40,20,60,0,40".
All coordinates are relative to the upper-left corner of the image (0,0). Each shape has a related URL. You can use any image software to know the coordinates of different positions
It is not difficult to put an HTML email link on your webpage but it can cause unnecessary spamming problem for your email account. There are people, who can run programs to harvest these types of emails and later use them for spamming in various ways.
You can have another option to facilitate people to send you emails. One option could be to use HTML forms to collect user data and then use PHP or CGI script to send an email.
A simple example, check our Contact Us Form. We take user feedback using this form and then we are using one CGI program which is collecting this information and sending us email to the one given email ID.
Note − You will learn about HTML Forms in HTML Forms and you will learn about CGI in our another tutorial Perl CGI Programming.

HTML Email Tag

HTML <a> tag provides you option to specify an email address to send an email. While using <a> tag as an email tag, you will use mailto: email address along with href attribute. Following is the syntax of using mailto instead of using http.
<a href = "mailto: abc@example.com">Send Email</a>
This code will generate the following link which you can use to send email.
Send Email
Now, if a user clicks this link, it launches one Email Client (like Lotus Notes, Outlook Express etc. ) installed on your user's computer. There is another risk to use this option to send email because if user do not have email client installed on their computer then it would not be possible to send email.

Default Settings

You can specify a default email subject and email body along with your email address. Following is the example to use default subject and body.
<a href = "mailto:abc@example.com?subject = Feedback&body = Message">
Send Feedback
</a>
This code will generate the following link which you can use to send email
HTML frames are used to divide your browser window into multiple sections where each section can load a separate HTML document. A collection of frames in the browser window is known as a frameset. The window is divided into frames in a similar way the tables are organized: into rows and columns.

Disadvantages of Frames

There are few drawbacks with using frames, so it's never recommended to use frames in your webpages −
  • Some smaller devices cannot cope with frames often because their screen is not big enough to be divided up.
  • Sometimes your page will be displayed differently on different computers due to different screen resolution.
  • The browser's back button might not work as the user hopes.
  • There are still few browsers that do not support frame technology.

Creating Frames

To use frames on a page we use <frameset> tag instead of <body> tag. The <frameset> tag defines, how to divide the window into frames. The rowsattribute of <frameset> tag defines horizontal frames and cols attribute defines vertical frames. Each frame is indicated by <frame> tag and it defines which HTML document shall open into the frame.
Note − The <frame> tag deprecated in HTML5. Do not use this element.

Example

Following is the example to create three horizontal frames −
 Live Demo
<!DOCTYPE html>
<html>

   <head>
      <title>HTML Frames</title>
   </head>
 
   <frameset rows = "10%,80%,10%">
      <frame name = "top" src = "/html/top_frame.htm" />
      <frame name = "main" src = "/html/main_frame.htm" />
      <frame name = "bottom" src = "/html/bottom_frame.htm" />
   
      <noframes>
         <body>Your browser does not support frames.</body>
      </noframes>
      
   </frameset>
   
</html>
This will produce the following result −

Example

Let's put the above example as follows, here we replaced rows attribute by cols and changed their width. This will create all the three frames vertically −
 Live Demo
<!DOCTYPE html>
<html>
   
   <head>
      <title>HTML Frames</title>
   </head>
   
   <frameset cols = "25%,50%,25%">
      <frame name = "left" src = "/html/top_frame.htm" />
      <frame name = "center" src = "/html/main_frame.htm" />
      <frame name = "right" src = "/html/bottom_frame.htm" />
      
      <noframes>
         <body>Your browser does not support frames.</body>
      </noframes>
   </frameset>
   
</html>
This will produce the following result −

The <frameset> Tag Attributes

Following are important attributes of the <frameset> tag −
Sr.NoAttribute & Description
1
cols
Specifies how many columns are contained in the frameset and the size of each column. You can specify the width of each column in one of the four ways −
Absolute values in pixels. For example, to create three vertical frames, use cols = "100, 500, 100".
A percentage of the browser window. For example, to create three vertical frames, use cols = "10%, 80%, 10%".
Using a wildcard symbol. For example, to create three vertical frames, use cols = "10%, *, 10%". In this case wildcard takes remainder of the window.
As relative widths of the browser window. For example, to create three vertical frames, use cols = "3*, 2*, 1*". This is an alternative to percentages. You can use relative widths of the browser window. Here the window is divided into sixths: the first column takes up half of the window, the second takes one third, and the third takes one sixth.
2
rows
This attribute works just like the cols attribute and takes the same values, but it is used to specify the rows in the frameset. For example, to create two horizontal frames, use rows = "10%, 90%". You can specify the height of each row in the same way as explained above for columns.
3
border
This attribute specifies the width of the border of each frame in pixels. For example, border = "5". A value of zero means no border.
4
frameborder
This attribute specifies whether a three-dimensional border should be displayed between frames. This attribute takes value either 1 (yes) or 0 (no). For example frameborder = "0" specifies no border.
5
framespacing
This attribute specifies the amount of space between frames in a frameset. This can take any integer value. For example framespacing = "10" means there should be 10 pixels spacing between each frames.

The <frame> Tag Attributes

Following are the important attributes of <frame> tag −
Sr.NoAttribute & Description
1
src
This attribute is used to give the file name that should be loaded in the frame. Its value can be any URL. For example, src = "/html/top_frame.htm" will load an HTML file available in html directory.
2
name
This attribute allows you to give a name to a frame. It is used to indicate which frame a document should be loaded into. This is especially important when you want to create links in one frame that load pages into an another frame, in which case the second frame needs a name to identify itself as the target of the link.
3
frameborder
This attribute specifies whether or not the borders of that frame are shown; it overrides the value given in the frameborder attribute on the <frameset> tag if one is given, and this can take values either 1 (yes) or 0 (no).
4
marginwidth
This attribute allows you to specify the width of the space between the left and right of the frame's borders and the frame's content. The value is given in pixels. For example marginwidth = "10".
5
marginheight
This attribute allows you to specify the height of the space between the top and bottom of the frame's borders and its contents. The value is given in pixels. For example marginheight = "10".
6
noresize
By default, you can resize any frame by clicking and dragging on the borders of a frame. The noresize attribute prevents a user from being able to resize the frame. For example noresize = "noresize".
7
scrolling
This attribute controls the appearance of the scrollbars that appear on the frame. This takes values either "yes", "no" or "auto". For example scrolling = "no" means it should not have scroll bars.
8
longdesc
This attribute allows you to provide a link to another page containing a long description of the contents of the frame. For example longdesc = "framedescription.htm"

Browser Support for Frames

If a user is using any old browser or any browser, which does not support frames then <noframes> element should be displayed to the user.
So you must place a <body> element inside the <noframes> element because the <frameset> element is supposed to replace the <body> element, but if a browser does not understand <frameset> element then it should understand what is inside the <body> element which is contained in a <noframes> element.
You can put some nice message for your user having old browsers. For example, Sorry!! your browser does not support frames. as shown in the above example.

Frame's name and target attributes

One of the most popular uses of frames is to place navigation bars in one frame and then load main pages into a separate frame.
Let's see following example where a test.htm file has following code −
 Live Demo
<!DOCTYPE html>
<html>

   <head>
      <title>HTML Target Frames</title>
   </head>
 
   <frameset cols = "200, *">
      <frame src = "/html/menu.htm" name = "menu_page" />
      <frame src = "/html/main.htm" name = "main_page" />
      
      <noframes>
         <body>Your browser does not support frames.</body>
      </noframes>
   </frameset>
 
</html>
Here, we have created two columns to fill with two frames. The first frame is 200 pixels wide and will contain the navigation menu bar implemented by menu.htm file. The second column fills in remaining space and will contain the main part of the page and it is implemented by main.htm file. For all the three links available in menu bar, we have mentioned target frame as main_page, so whenever you click any of the links in menu bar, available link will open in main page.
Following is the content of menu.htm file
 Live Demo
<!DOCTYPE html>
<html>

   <body bgcolor = "#4a7d49">
      <a href = "http://www.google.com" target = "main_page">Google</a>
      <br />
      <br />
      
      <a href = "http://www.microsoft.com" target = "main_page">Microsoft</a>
      <br />
      <br />
      
      <a href = "http://news.bbc.co.uk" target = "main_page">BBC News</a>
   </body>
 
</html>
Following is the content of main.htm file −
 Live Demo
<!DOCTYPE html>
<html>

   <body bgcolor = "#b5dcb3">
      <h3>This is main page and content from any link will be displayed here.</h3>
      <p>So now click any link and see the result.</p>
   </body>
 
</html>
When we load test.htm file, it produces following result −

Now you can try to click links available in the left panel and see the result. The targetattribute can also take one of the following values −
Sr.NoOption & Description
1
_self
Loads the page into the current frame.
2
_blank
Loads a page into a new browser window. Opening a new window.
3
_parent
Loads the page into the parent window, which in the case of a single frameset is the main browser window.
4
_top
Loads the page into the browser window, replacing any current frames.
5
targetframe
  • Loads the page into a named targetframe.
You can define an inline frame with HTML tag <iframe>. The <iframe> tag is not somehow related to <frameset> tag, instead, it can appear anywhere in your document. The <iframe> tag defines a rectangular region within the document in which the browser can display a separate document, including scrollbars and borders. An inline frame is used to embed another document within the current HTML document.
The src attribute is used to specify the URL of the document that occupies the inline frame.

Example

Following is the example to show how to use the <iframe> −
 Live Demo
<!DOCTYPE html>
<html>

   <head>
      <title>HTML Iframes</title>
   </head>
 
   <body>
      <p>Document content goes here...</p>
      
      <iframe src = "/html/menu.htm" width = "555" height = "200">
         Sorry your browser does not support inline frames.
      </iframe>
      
      <p>Document content also go here...</p>
   </body>
 
</html>
This will produce the following result −

The <Iframe> Tag Attributes

Most of the attributes of the <iframe> tag, including name, class, frameborder, id, longdesc, marginheight, marginwidth, name, scrolling, style, and title behave exactly like the corresponding attributes for the <frame> tag.
Note − The frameborder, marginwidth, longdesc, scrolling, marginheight attributes deprecated in HTML5. Do not use these attributes.
Sr.NoAttribute & Description
1
src
This attribute is used to give the file name that should be loaded in the frame. Its value can be any URL. For example, src = "/html/top_frame.htm" will load an HTML file available in html directory.
2
name
This attribute allows you to give a name to a frame. It is used to indicate which frame a document should be loaded into. This is especially important when you want to create links in one frame that load pages into an another frame, in which case the second frame needs a name to identify itself as the target of the link.
3
frameborder
This attribute specifies whether or not the borders of that frame are shown; it overrides the value given in the frameborder attribute on the <frameset> tag if one is given, and this can take values either 1 (yes) or 0 (no).
4
marginwidth
This attribute allows you to specify the width of the space between the left and right of the frame's borders and the frame's content. The value is given in pixels. For example marginwidth = "10".
5
marginheight
This attribute allows you to specify the height of the space between the top and bottom of the frame's borders and its contents. The value is given in pixels. For example marginheight = "10".
6
height
This attribute specifies the height of <iframe>.
7
scrolling
This attribute controls the appearance of the scrollbars that appear on the frame. This takes values either "yes", "no" or "auto". For example scrolling = "no" means it should not have scroll bars.
8
longdesc
This attribute allows you to provide a link to another page containing a long description of the contents of the frame. For example longdesc = "framedescription.htm"
9
width
This attribute specifies the width of <iframe>
All the HTML elements can be categorized into two categories (a) Block Level Elements (b)Inline Elements.

Block Elements

Block elements appear on the screen as if they have a line break before and after them. For example, the <p>, <h1>, <h2>, <h3>, <h4>, <h5>, <h6>, <ul>, <ol>, <dl>, <pre>, <hr />, <blockquote>, and <address> elements are all block level elements. They all start on their own new line, and anything that follows them appears on its own new line.

Inline Elements

Inline elements, on the other hand, can appear within sentences and do not have to appear on a new line of their own. The <b>, <i>, <u>, <em>, <strong>, <sup>, <sub>, <big>, <small>, <li>, <ins>, <del>, <code>, <cite>, <dfn>, <kbd>, and <var> elements are all inline elements.

Grouping HTML Elements

There are two important tags which we use very frequently to group various other HTML tags (i) <div> tag and (ii) <span> tag

The <div> tag

This is the very important block level tag which plays a big role in grouping various other HTML tags and applying CSS on group of elements. Even now <div> tag can be used to create webpage layout where we define different parts (Left, Right, Top etc.) of the page using <div> tag. This tag does not provide any visual change on the block but this has more meaning when it is used with CSS.

Example

Following is a simple example of <div> tag. We will learn Cascading Style Sheet (CSS) in a separate chapter but we used it here to show the usage of <div> tag −
 Live Demo
<!DOCTYPE html>
<html>
   
   <head>
      <title>HTML div Tag</title>
   </head>
 
   <body>
      <!-- First group of tags -->
      <div style = "color:red">
         <h4>This is first group</h4>
         <p>Following is a list of vegetables</p>
         
         <ul>
            <li>Beetroot</li>
            <li>Ginger</li>
            <li>Potato</li>
            <li>Radish</li>
         </ul>
      </div>

      <!-- Second group of tags -->
      <div style = "color:green">
         <h4>This is second group</h4>
         <p>Following is a list of fruits</p>
         
         <ul>
            <li>Apple</li>
            <li>Banana</li>
            <li>Mango</li>
            <li>Strawberry</li>
         </ul>
      </div>
   </body>
   
</html>
This will produce the following result −

The <span> tag

The HTML <span> is an inline element and it can be used to group inline-elements in an HTML document. This tag also does not provide any visual change on the block but has more meaning when it is used with CSS.
The difference between the <span> tag and the <div> tag is that the <span> tag is used with inline elements whereas the <div> tag is used with block-level elements.

Example

Following is a simple example of <span> tag. We will learn Cascading Style Sheet (CSS) in a separate chapter but we used it here to show the usage of <span> tag −
 Live Demo
<!DOCTYPE html>
<html>

   <head>
      <title>HTML span Tag</title>
   </head>
 
   <body>
      <p>This is <span style = "color:red">red</span> and this is
         <span style = "color:green">green</span></p>
   </body>
 
</html>

By default, your webpage background is white in color. You may not like it, but no worries. HTML provides you following two good ways to decorate your webpage background.


    

  • HTML Background with Colors
    • 

  • HTML Background with Images
    • 




Now let's see both the approaches one by one using appropriate examples.



Html Background with Colors



The bgcolor attribute is used to control the background of an HTML element, specifically page body and table backgrounds.





Note − The bgcolor attribute deprecated in HTML5. Do not use this attribute.





Following is the syntax to use bgcolor attribute with any HTML tag.


<tagname bgcolor = "color_value"...>




This color_value can be given in any of the following formats −


<!-- Format 1 - Use color name -->
<table bgcolor = "lime" >
 
<!-- Format 2 - Use hex value -->
<table bgcolor = "#f1f1f1" >
 
<!-- Format 3 - Use color value in RGB terms -->
<table bgcolor = "rgb(0,0,120)" >




Example



Here are the examples to set background of an HTML tag −

 Live Demo
<!DOCTYPE html>
<html>

   <head>
      <title>HTML Background Colors</title>
   </head>
 
   <body>
      <!-- Format 1 - Use color name -->
      <table bgcolor = "yellow" width = "100%">
         <tr>
            <td>
               This background is yellow
            </td>
         </tr>
      </table>
 
      <!-- Format 2 - Use hex value -->
      <table bgcolor = "#6666FF" width = "100%">
         <tr>
            <td>
               This background is sky blue
            </td>
         </tr>
      </table>
 
      <!-- Format 3 - Use color value in RGB terms -->
      <table bgcolor = "rgb(255,0,255)" width = "100%">
         <tr>
            <td>
               This background is green
            </td>
         </tr>
      </table>
   </body>
   
</html>



This will produce the following result −



Html Background with Images



The background attribute can also be used to control the background of an HTML element, specifically page body and table backgrounds. You can specify an image to set background of your HTML page or table.





Note − The background attribute deprecated in HTML5. Do not use this attribute.





Following is the syntax to use background attribute with any HTML tag.





Note − The background attribute is deprecated and it is recommended to use Style Sheet for background setting.




<tagname background = "Image URL"...>




The most frequently used image formats are JPEG, GIF and PNG images.



Example



Here are the examples to set background images of a table.

 Live Demo
<!DOCTYPE html>
<html>

   <head>
      <title>HTML Background Images</title>
   </head>
 
   <body>
      <!-- Set table background -->
      <table background = "/images/html.gif" width = "100%" height = "100">
         <tr><td>
            This background is filled up with HTML image.
         </td></tr>
      </table>
   </body>
   
</html>



This will produce the following result −



Patterned & Transparent Backgrounds



You might have seen many pattern or transparent backgrounds on various websites. This simply can be achieved by using patterned image or transparent image in the background.



It is suggested that while creating patterns or transparent GIF or PNG images, use the smallest dimensions possible even as small as 1x1 to avoid slow loading.



Example



Here are the examples to set background pattern of a table −

 Live Demo
<!DOCTYPE html>
<html>




   <head>
      <title>HTML Background Images</title>
   </head>
 
   <body>
      <!-- Set a table background using pattern -->
      <table background = "/images/pattern1.gif" width = "100%" height = "100">
         <tr>
            <td>
               This background is filled up with a pattern image.
            </td>
         </tr>
      </table>

      <!-- Another example on table background using pattern -->
      <table background = "/images/pattern2.gif" width = "100%" height = "100">
         <tr>
            <td>
               This background is filled up with a pattern image.
            </td>
         </tr>
      </table>
   </body>
   
</html>



Colors are very important to give a good look and feel to your website. You can specify colors on page level using <body> tag or you can set colors for individual tags using bgcolor attribute.



The <body> tag has following attributes which can be used to set different colors −


    

  • 
bgcolor − sets a color for the background of the page.
    

    • 

  • 
text − sets a color for the body text.
    

    • 

  • 
alink − sets a color for active links or selected links.
    

    • 

  • 
link − sets a color for linked text.
    

    • 

  • 
vlink − sets a color for visited links − that is, for linked text that you have already clicked on.
    

    • 




HTML Color Coding Methods



There are following three different methods to set colors in your web page −


    

  • 
Color names − You can specify color names directly like green, blue or red.
    

    • 

  • 
Hex codes − A six-digit code representing the amount of red, green, and blue that makes up the color.
    

    • 

  • 
Color decimal or percentage values − This value is specified using the rgb( ) property.
    

    • 




Now we will see these coloring schemes one by one.



HTML Colors - Color Names



You can specify direct a color name to set text or background color. W3C has listed 16 basic color names that will validate with an HTML validator but there are over 200 different color names supported by major browsers.



Note − Check a complete list of HTML Color Name.



W3C Standard 16 Colors



Here is the list of W3C Standard 16 Colors names and it is recommended to use them.




BlackGraySilverWhite


YellowLimeAquaFuchsia


RedGreenBluePurple


MaroonOliveNavyTeal





Example



Here are the examples to set background of an HTML tag by color name −

 Live Demo
<!DOCTYPE html>
<html>

   <head>
      <title>HTML Colors by Name</title>
   </head>
 
   <body text = "blue" bgcolor = "green">
      <p>Use different color names for for body and table and see the result.</p>
      
      <table bgcolor = "black">
         <tr>
            <td>
               <font color = "white">This text will appear white on black background.</font>
            </td>
         </tr>
      </table>
   </body>
   
</html>



HTML Colors - Hex Codes



A hexadecimal is a 6 digit representation of a color. The first two digits(RR) represent a red value, the next two are a green value(GG), and the last are the blue value(BB).



A hexadecimal value can be taken from any graphics software like Adobe Photoshop, Paintshop Pro or MS Paint.



Each hexadecimal code will be preceded by a pound or hash sign #. Following is a list of few colors using hexadecimal notation.




ColorColor HEX


#000000


#FF0000


#00FF00


#0000FF


#FFFF00


#00FFFF


#FF00FF


#C0C0C0


#FFFFFF





Example



Here are the examples to set background of an HTML tag by color code in hexadecimal −

 Live Demo
<!DOCTYPE html>
<html>

   <head>
      <title>HTML Colors by Hex</title>
   </head>
 
   <body text = "#0000FF" bgcolor = "#00FF00">
      <p>Use different color hexa for for body and table and see the result.</p>
      
      <table bgcolor = "#000000">
         <tr>
            <td>
               <font color = "#FFFFFF">This text will appear white on black background.</font>
            </td>
         </tr>
      </table>
   </body>
   
</html>



HTML Colors - RGB Values



This color value is specified using the rgb( )property. This property takes three values, one each for red, green, and blue. The value can be an integer between 0 and 255 or a percentage.





Note − All the browsers does not support rgb() property of color so it is recommended not to use it.





Following is a list to show few colors using RGB values.




ColorColor RGB


rgb(0,0,0)


rgb(255,0,0)


rgb(0,255,0)


rgb(0,0,255)


rgb(255,255,0)


rgb(0,255,255)


rgb(255,0,255)


rgb(192,192,192)


rgb(255,255,255)





Example



Here are the examples to set background of an HTML tag by color code using rgb() values −

 Live Demo
<!DOCTYPE html>
<html>

   <head>
      <title>HTML Colors by RGB code</title>
   </head>
 
   <body text = "rgb(0,0,255)" bgcolor = "rgb(0,255,0)">
      <p>Use different color code for for body and table and see the result.</p>
      
      <table bgcolor = "rgb(0,0,0)">
         <tr>
            <td>
               <font color = "rgb(255,255,255)">This text will appear white on black background.</font>
            </td>
         </tr>
      </table>
   </body>
   
</html>



Browser Safe Colors



Here is the list of 216 colors which are supposed to be safest and computer independent colors. These colors very from hexa code 000000 to FFFFFF and they will be supported by all the computers having 256 color palette.




0000000000330000660000990000CC0000FF


0033000033330033660033990033CC0033FF


0066000066330066660066990066CC0066FF


0099000099330099660099990099CC0099FF


00CC0000CC3300CC6600CC9900CCCC00CCFF


00FF0000FF3300FF6600FF9900FFCC00FFFF


3300003300333300663300993300CC3300FF


3333003333333333663333993333CC3333FF


3366003366333366663366993366CC3366FF


3399003399333399663399993399CC3399FF


33CC0033CC3333CC6633CC9933CCCC33CCFF


33FF0033FF3333FF6633FF9933FFCC33FFFF


6600006600336600666600996600CC6600FF


6633006633336633666633996633CC6633FF


6666006666336666666666996666CC6666FF


6699006699336699666699996699CC6699FF


66CC0066CC3366CC6666CC9966CCCC66CCFF


66FF0066FF3366FF6666FF9966FFCC66FFFF


9900009900339900669900999900CC9900FF


9933009933339933669933999933CC9933FF


9966009966339966669966999966CC9966FF


9999009999339999669999999999CC9999FF


99CC0099CC3399CC6699CC9999CCCC99CCFF


99FF0099FF3399FF6699FF9999FFCC99FFFF


CC0000CC0033CC0066CC0099CC00CCCC00FF


CC3300CC3333CC3366CC3399CC33CCCC33FF


CC6600CC6633CC6666CC6699CC66CCCC66FF


CC9900CC9933CC9966CC9999CC99CCCC99FF


CCCC00CCCC33CCCC66CCCC99CCCCCCCCCCFF


CCFF00CCFF33CCFF66CCFF99CCFFCCCCFFFF


FF0000FF0033FF0066FF0099FF00CCFF00FF


FF3300FF3333FF3366FF3399FF33CCFF33FF


FF6600FF6633FF6666FF6699FF66CCFF66FF


FF9900FF9933FF9966FF9999FF99CCFF99FF


FFCC00FFCC33FFCC66FFCC99FFCCCCFFCCFF


FFFF00FFFF33FFFF66FFFF99FFFFCC

at No comments:
Subscribe to: Posts (Atom)

Featured Post

  • (no title)
    C++ Exception Handling part 2 An exception is a problem that arises during the execution of a program. A C++ exception is a response to...
  • (no title)
    C++ Templates part 5 Templates are the foundation of generic programming, which involves writing code in a way that is independent of a...
  • (no title)
    C++ advance C++ Files and Streams part1 So far, we have been using the  iostream  standard library, which provides  cin  and  cout  me...