Each time the visitor clicks a link in the left navigation frame, the content in the main frame displays the selected page.. Sometimes you may want to work on your frame document before
Trang 1In addition, the frameset is defined as having no borders, but the first frame is supposed
to have a border How do you resolve this problem? You can apply three simple rules:
n Attributes in the outermost frameset have the lowest priority
n Attributes are overridden by attributes in a nested <frameset>tag
n Any bordercolorattribute in the current frame overrides previous ones in
<frameset>tags
Additional Attributes
Table 17.1 shows a few extra attributes for the <frame>tag These attributes can give you
additional control over how the user interacts with your frames Other attributes control
margins or spacing between frames and whether scrollbars appear when required
TABLE 17.1 Control Attributes for the <frame> Tag
(default).
longdesc URL Specifies a URL that provides a longer
description of the contents of the frameset.
Primarily used with nonvisual browsers.
marginheight pixels To adjust the margin that appears above
and below a document within a frame, set marginheight to the number indicated by
pixels.
marginwidth pixels The marginwidth attribute enables you to
adjust the margin on the left and right sides
of a frame to the number indicated by pixels.
name string Assigns a name to the frame for targeting
purposes.
of borders around each frame on the current screen by grabbing the borders and moving them with the mouse To lock the borders of
a frame and prevent them from being moved, use the noresize attribute.
scrolling auto (Default) If the content of a frame takes up
more space than the area available, frames-compatible browsers automatically add scroll-bars to either the right side or the bottom of the frame so that the users can scroll through the document.
Trang 2▼
TABLE 17.1 Continued
scrolling no Setting the value of scrolling to no
dis-ables the use of scrollbars for the current frame (Note that if you do this but the docu-ment contains more text than can fit inside the frame, users can't scroll the additional text into view.)
scrolling yes If you set scrolling to yes , scrollbars are
included in the frame even if they aren’t required.
src URL Specifies the URL of the initial source
docu-ment that appears in a frame when the frameset first opens in the browser.
Creating Complex Framesets
The framesets you’ve learned about so far are the most basic types of frames that can be
displayed In day-to-day use, however, you’ll rarely use these basic frame designs On all
but the simplest sites, you’ll most likely want to use more complex framesets
Therefore, to help you understand the possible combinations of frames, links, images,
and documents that can be used by a website, this section explores complex framesets
Task: Exercise 17.2: Creating the Content Pages for Your
Frameset
Most commonly, framesets are used to keep navigational elements in view as the user
scrolls through the contents of the document Each time the visitor clicks a link in the
left navigation frame, the content in the main frame displays the selected page The (very
silly) frameset that you’ll create in this exercise demonstrates this technique Although
it’s not a practical example, it’s simple, fun, and demonstrates the same techniques you
would use for a navigation bar
When you design a web page that uses frames, you normally design the frameset before
you go through all the trouble of designing the content that goes into it That’s because
you’ll want to know how big your frames are going to be before you start designing
graphics and other page content to put into them
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Trang 3I’m doing things a little backward here, but for good reason It might help you to better
understand how things fit together if you see real content in the frames as you design the
frameset For this reason, I have you design the content first
The following content pages don’t include any of the frameset tags discussed so far
There are eight pages in all, but I promise that I keep the code for these pages brief
Ready?
Sometimes you may want to work on your frame document before you’ve finished all the pages that will be displayed in the frames.
However, your frameset won’t be displayed properly when it’s loaded into a frames-compatible browser for testing unless you define <frame> tags that include valid documents If you want to design a frameset before you create the content, you can create a small empty HTML document called dummy.html and use it for all your frame testing.
The frameset that you’ll create in Exercises 17.3 through 17.7 consists of three frames
The layout of the frameset will be as shown in Figure 17.11 The frameset page loads
first and instructs the browser to divide the browser window into three frames Next, it
loads the three pages that appear in the top, left, and main frames Finally, if a user
browses to the frameset without a frames-compatible browser, an alternative page will
appear
TIP
FIGURE 17.11
You’ll create a
frameset that
con-sists of three
frames: top, left,
and main.
The top frame always displays the same web page: away.html The choices.htmlpage
that appears in the frame on the left side contains a list of links to six different pages
namedreason1.htmlthroughreason6.html Each of these six pages will load into the
main frame on the bottom-right portion of the frameset
Trang 4Start with the page displayed in the top frame This page will always appear in the
frameset Here you can include any information you want to display permanently as
visi-tors browse through your site Real-world examples for the content of this frame include
the name of your website, a site logo, a link to your email address, or other similar
con-tent Type in the following code and save it to your hard drive as away.html:
<!DOCTYPE html>
<html>
<head>
<title>I’m Away from My Desk Because</title>
<style type=”text/css” media=”screen”>
body { background-color: #cc6600; color: #ffcc33; }
</style>
</head>
<body>
<h3>I’m Away from My Desk, because </h3>
</body>
</html>
Figure 17.12 shows this page
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FIGURE 17.12
The top frame in
the frameset.
Next, you’ll create the left frame in the frameset On real websites, this is typically the
frame used for text or image navigation links that take your visitors to several different
key pages on your site For example, a personal site might have a navigation bar that
takes its visitors to a home page, a guest book, a links page, and other sections of
inter-est A corporate or business site could contain links for products, customer support,
fre-quently asked questions, employment opportunities, and so on
The contents page in the following example works exactly the same way that a
real-world navigation bar does When the appropriate link is selected, it displays one of the
six pages in the main frame of the frameset The contents page contains links to six
pages,reason1.htmlthroughreason6.html, which you’ll create next.
After you enter the following code into a new page, save it to your hard drive in the same
directory as the first page and name it choice.html:
Trang 5Input▼
<!DOCTYPE html>
<html>
<head>
<title>Reason I’m Out</title>
<style type=”text/css” media=”screen”>
body {
color: #ffcc66;
background-color: #006699;
}
a { color: #ffffff; } a:visited { color: #66ccff; } a:active { color: #ff6666; }
</style>
</head>
<body>
<p>Select a reason:</p>
<p><a href=”reason1.html”>Reason 1</a></p>
<p><a href=”reason2.html”>Reason 2</a></p>
<p><a href=”reason3.html”>Reason 3</a></p>
<p><a href=”reason4.html”>Reason 4</a></p>
<p><a href=”reason5.html”>Reason 5</a></p>
<p><a href=”reason6.html”>Reason 6</a></p>
</body>
</html>
Your page should look as shown in Figure 17.13 when you open it in a browser
FIGURE 17.13
The left frame in
the frameset.
Now you need to create the six pages that will appear in the main frame when the visitor
selects one of the links in the contents frame The main frame is designed to display
pages that normally you would display in a full browser window However, if you’re
going to display your pages in a frameset that has a left navigation bar, you’ll have to
account for the reduced size of the frame in your design
Trang 6To keep the page examples relatively easy, I’ve given them all the same basic
appear-ance This means that the code for all of these pages is pretty much the same The only
items that change from page to page are the following:
n The title of the page
n The description of my current mood
n The text that describes what each image means
To create the first of the six pages that will appear in the main frame, type the following
code into a new page and save it as reason1.html:
Input▼
<!DOCTYPE html>
<html>
<head>
<title>Reason 1 - Forgot My Lunch</title>
<style type=”text/css” media=”screen”>
body {
background-color: #ffffff;
font: 200% bold;
text-align: center;
}
</style>
</head>
<body>
<p>I forgot my lunch at home.</p>
</body>
</html>
Figure 17.14 shows what this page should look like in a browser
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Output
FIGURE 17.14
The first of the six
pages that appear
in the main frame.
Trang 7You code the remaining five pages for the main frame similarly Modify the page you
just created to build the second of the six main pages The only differences from the
pre-vious code (reason1.html) are shown with a gray background Save the new page as
reason2.html The complete code appears as follows:
<!DOCTYPE html>
<html>
<head>
<title>Reason 2 - By the Water Cooler</title>
<style type=”text/css” media=”screen”>
body {
background-color: #ffffff;
font: 200% bold;
text-align: center;
}
</style>
</head>
<body>
<p>I’m flirting by the water cooler.</p>
</body>
</html>
For the third page, modify the code again and save it as reason3.html The complete
code appears as follows:
<!DOCTYPE html>
<html>
<head>
<title>Reason 3 - Don’t Ask!</title>
<style type=”text/css” media=”screen”>
body {
background-color: #ffffff;
font: 200% bold;
text-align: center;
}
</style>
</head>
<body>
<p>None of your business!</p>
</body>
</html>
Here’s the fourth page (reason4.html):
<!DOCTYPE html>
<html>
<head>
<title>Reason 4 - Out to Lunch</title>
<style type=”text/css” media=”screen”>
Trang 8body {
background-color: #ffffff;
font: 200% bold;
text-align: center;
}
</style>
</head>
<body>
<p>I’m out to lunch.</p>
</body>
</html>
The fifth page (reason5.html) looks like the following:
<!DOCTYPE html>
<html>
<head>
<title>Reason 5 - Boss’s Office</title>
<style type=”text/css” media=”screen”>
body {
background-color: #ffffff;
font: 200% bold;
text-align: center;
}
</style>
</head>
<body>
<p>The boss called me in his office.<p>
</body>
</html>
The last main page (reason6.html) appears as follows:
<!DOCTYPE html>
<html>
<head>
<title>Reason 6 - I Don’t Work Here Anymore</title>
<style type=”text/css” media=”screen”>
body {
background-color: #ffffff;
font: 200% bold;
text-align: center;
}
</style>
</head>
<body>
<p>I just got fired.<p>
</body>
</html>
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Trang 9▼
Now you have the six pages that will appear in the main frame of the frameset You’re
finally ready to build the frameset
Task: Exercise 17.3: Combining rows and cols
To remind you of the basic layout of the frameset that you’ll create, Figure 17.15 is
another look at the complete page It provides a simple example of how you can combine
framesets to create complex designs
▲
Output
FIGURE 17.15
The frameset with
three frames: top,
left, and main.
When you’re designing complex frame layouts, a storyboard is an invaluable tool It helps you block out the structure of a frameset, and it can prove invaluable when you’re adding hyperlinks (as you’ll see in Exercise 17.5, “Using Named Frames and Hyperlinks”).
In Figure 17.15, the right section of the screen is split into two horizontal frames, and the
third frame at the left of the page spans the entire height of the screen To create a
frame-set document that describes this layout, open your text editor and enter the following
basic HTML structural details:
<!DOCTYPE html>
<html>
<head>
<title>Why I’m Away Frameset</title>
</head>
<frameset>
</frameset>
</html>
TIP
Trang 10Next, you must decide whether you need to use a rowsorcolsattribute in your base
<frameset> Look at your storyboard—in this case Figure 17.15—and work out whether
any frame areas extend right across the screen or from the top to the bottom If any
frames extend from the top to the bottom, as in this example, you need to start with a
colsframeset; otherwise, you need to start with a rowsframeset On the other hand, if
no frames extend completely across the screen either vertically or horizontally, you
should start with a colsframeset
To put it more simply, here are three easy-to-remember rules:
n Left to right, use rows
n Top to bottom, use cols
n Can’t decide, use cols
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The reasoning behind the use of the “left to right, use rows ” rule relates to how frames-compatible browsers create frames Each separate <frameset> definition can split the screen (or a frame) either vertically or horizontally, but not both ways For this reason, you need to define your framesets in a logical order to ensure that you achieve the layout you want.
In Figure 17.15, the left frame extends across the screen from top to bottom As a result,
you need to start with a colsframeset by using the rules mentioned previously To define
the base frameset, enter the following:
<frameset cols=“125,*”>
<frame src=“choice.html”> <! loads the choices page into the left frame >
<frame src=“dummy.html”> <! this line is only temporary >
</frameset>
Writing this code splits the screen into two sections The first line defines a small frame
at the left of the screen that is 125 pixels wide, and a large frame at the right of the
screen that uses the rest of the available space
As mentioned earlier in this lesson, the frameset document itself doesn’t describe the
contents of each frame The documents specified in the srcattribute of the <frame>
actu-ally contain the text, images, and tags displayed by the frameset You can see an example
of this tag in the second and third lines of the preceding code The second line specifies
the URL of the web page in the left frame (the choice.htmlpage that you created
ear-lier) The third line would display a web page named dummy.html(if you created one,
that is), but we’re just using this as a placeholder for the next exercise
NOTE
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