Sams Teach Yourself HTML and CSS in 24 Hours (7th Edition)

The problem with the nine-frame arrangement in Figure 16.3 is that it looks ugly and serves no practical purpose with all those annoying scrollbars. We can fix that.

The ugly parts are the gray dividers between the frames, which completely ruin the effect of surrounding the center frame with nicely designed graphics. There also isn't enough room in the top and bottom frames to display the graphics without scrollbars. Fortunately, there are HTML commands to get rid of the frame dividers, make more space in small frames by reducing the size of the margins, and force frames not to have scrollbars.

Coffee Break

To see scrollbars in action on a real-world web page that takes advantage of frames, visit the Clint Eastwood web site at http://www.clinteastwood.net/. This site uses frames heavily to allow you to navigate and scroll through content within limited regions of the page.

Before you read about these HTML magic tricks, take a look at the dramatic results they can achieve. Figure 16.5 is another version of the nine-frame window displaying the same web pages shown in Figure 16.3. Obviously, Figure 16.5 looks much nicer! In Listing 16.5, you can see the anti-ugliness medication I gave to the frameset you saw in Figure 16.3.

Listing 16.5. Nine Separate Web Pages Displayed in Nine Frames

<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Frameset//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-frameset.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en"> <head> <title>The Entropy Almanac</title> </head> <frameset rows="43,*,43" border="0"> <frameset cols="43,*,43"> <frame src="/books/4/158/1/html/2/ctoplft.html" name="toplft" scrolling="no" frameborder="0" /> <frame src="/books/4/158/1/html/2/bordtop.html" name="top" scrolling="no" frameborder="0" marginheight="1" /> <frame src="/books/4/158/1/html/2/ctoprgt.html" name="toprgt" scrolling="no" frameborder="0" /> </frameset> <frameset cols="43,*,43"> <frame src="/books/4/158/1/html/2/bordlft.html" name="left" scrolling="no" frameborder="0" /> <frame src="/books/4/158/1/html/2/main.html" name="main" frameborder="0" /> <frame src="/books/4/158/1/html/2/bordrgt.html" name="right" scrolling="no" frameborder="0" /> </frameset> <frameset cols="43,*,43"> <frame src="/books/4/158/1/html/2/cbtmlft.html" name="btmlft" scrolling="no" frameborder="0" /> <frame src="/books/4/158/1/html/2/bordbtm.html" name="btm" scrolling="no" frameborder="0" marginheight="1" /> <frame src="/books/4/158/1/html/2/cbtmrgt.html" name="btmrgt" scrolling="no" frameborder="0" /> </frameset> </frameset> </html>

Figure 16.5. This is the page whose code is shown in Listing 16.5. By adding some attributes to the <frame /> tags, I was able to make the frames look much nicer.

By the Way

One problem with this code is the border attribute of the <frameset> tag, which technically isn't supported in XHTML. In other words, the document in Listing 16.5 will not validate even with the XHTML 1.0 Transitional DTD because of the border attribute. If you recall, you typically replace the border attribute with CSS styles to achieve the same results and conform to XHTML. The problem is that no current web browsers allow you to achieve the same results as the border="0" setting via CSS. So if you get rid of the border attribute, you'll see a nasty-looking gray border between the frames. Because I always err on the side of practicality, I opted to have the page look good and forego validation, knowing that eventually browsers will mend their ways.

In addition to the id and name attributes, the <frame /> tag can take the following special frame-related attributes:

  • marginwidth Left and right margins of the frame (in pixels).

  • marginheight Top and bottom margins of the frame (in pixels).

  • scrolling Display scrollbar for the frame? ("yes" or "no")

  • frameborder Display dividers between this frame and adjacent frames? (1 means yes, 0 means no)

  • noresize Don't allow this frame to be resized by the user.

marginwidth and marginheight are pretty self-explanatory, but it's worth taking a close look at each of the other attributes.

Normally, any frame that isn't big enough to hold all of its contents will have its own scrollbar(s). The top and bottom frames you saw earlier in Figure 16.3 are examples. If you don't want a particular frame to ever display scrollbars, you can put scrolling="no" in the <frame> tag. Conversely, scrolling="yes" forces both horizontal and vertical scrollbars to appear, whether or not they are needed.

Did you Know?

When graphics barely fit within a small frame, web browsers often display scrollbars that scroll only a few pixels down and have no real purpose. Rather than making the frame bigger (and taking up valuable window real estate with empty margin space), you will often want to just turn off the scrollbars with scrolling="no".

The only situation I can think of in which you might want to use scrolling="yes" is if some graphics won't line up right unless you can count on the scrollbars always being there. Chances are that you'll never need scrolling="yes".

People viewing your frames can ordinarily resize them by grabbing the frame borders with the mouse and dragging them around. If you don't want anyone messing with the size of a frame, put noresize="noresize" in the <frame /> tag.

Frames are flexible enough to allow you to control the size of frame borders or eliminate borders altogether. This makes a frame document look just like a regular web page, with no ugly lines breaking it up. Just put a frameborder="0" attribute in every single <frame /> tagnot just in the <frameset> tags.

When used together with custom graphics, borderless frames can allow you to create sites that are easier to navigate and more pleasant to visit. For example, when someone visits the site shown in Figure 16.5 and clicks one of the navigation choices in the bottom frame, the page he chose comes up in the middle frame quickly because the title graphic, navigation buttons, and border graphics all remain in place. The frames also automatically adapt to changes in the size of the browser window, so the nice "picture frame" effect looks just as good at 1,024x768 resolution and higher resolutions as it does at 800x600.

Coffee Break

I haven't made too big of a deal out of the fact that many web designers and users don't like frames. And unfortunately, it's beyond the scope of this lesson to detour into a philosophical debate about whether frames are good or evil. However, if you'd like to learn more about the pros and cons of using frames in your own pages, here's a great site you can visit to learn more: http://www.yourhtmlsource.com/frames/goodorbad.html.

Figure 16.6 shows the result of clicking the Facts & Forecasts link in the screen shown in Figure 16.5. Note that the middle frame gets its own scrollbar whenever the contents are too big to fit in the frame.

Figure 16.6. Clicking a link at the top of the screen shown in Figure 16.5 brings up a new page in the middle frame, without redrawing any of the other frames.

By the Way

If you'd like to get more advanced with frames, you might want to look into inline frames, which are frames you can place directly within a section of text in a page. Inline frames are created using the <iframe> tag, as the following code demonstrates:

[View full width]

<html> <head> <title>bios</title> </head> <body> <h1>Short Bios</h1> <p> <iframe name="bioframe" src="/books/4/158/1/html/2/mybio.html" width="200" height="200"> </iframe> </p> <p> <a href="yourbio.html" target="bioframe">Your Bio</a> </p> <p> <a href="mybio.html" target="bioframe">My Bio</a> </p> </body> </html>

This code displays the page mybio.html in a 200x200-pixel region, under the heading Short Bios. If the document mybio.html doesn't fit in that small region, it would have its own little scrollbar(s) next to it. Clicking the Your Bio link would replace the contents of the 200x200-pixel region with yourbio.html. Clicking My Bio would put mybio.html back into that region.

You can view an <iframe> example online at http://www.samspublishing.com/.

Related

Категории