Dreamweaver.MX.1002004.The.Missing.Manual [Electronic resources] نسخه متنی

17.5 Library Basics

Imagine this situation: You manage a relatively large Web site consisting of thousands
of Web pages. At the bottom of each page is a simple copyright notice: "Copyright
MyBigCompany. We reserve all rightsnational, international, commercial, noncommercial,
and mineralto the content contained on these pages."

Each time you add another page to the site, you could retype the copyright message,
but this approach invites both typographic errors and carpal tunnel syndrome. And
if you must format this text too, then you're in for quite a bit of work.

Fortunately, Dreamweaver's Library can turn any selection in the document window
(a paragraph, an image, a table) into a reusable chunk of HTML that you can easily
drop into any Dreamweaver document. The Library, in other words, is a great place
to store copyright notices, navigation bars, or any other chunks of HTML you use
frequently.

But this is only half of the Library's power. Each Library item that you add to a Web
page is actually only a copy, which remains linked to the original. Thanks to this link,
whenever you update the original Library item, you get a chance to update every page
that uses that item.

Suppose your company is bought, for example, and the legal department orders you
to change the copyright notice to "Copyright MyBigCompany, a subsidiary of aMuch-
BiggerCompany" on each of the Web site's 10,000 pages. If you had cleverly inserted
the original copyright notice as a Library item, you could take care of this task in the
blink of an eye. Just open the item in the Library, make the required changes, save it,
and let Dreamweaver update all the pages for you (Figure 17-3).

Compared to Snippets, Library items are much smarter. They possess the unique
ability to update the same material on an entire site's worth of files in seconds and
can successfully deal with links and images. Unlike Snippets, however, Dreamweaver's
Library feature is site-specific. In other words, each site that you've defined in Dreamweaver
has its own Library. You can't use a Library item from one site on a page from
a different site.

The Museum of Modern
Arts home page, which
was created with Dreamweaver,
takes advantage
of Library elements. The
site's logo (circled) is one
of twelve Library items
on this page. If the Museum
decides to change
its logo (or any property
of the logo such as the
image's Alt attribute), it
can update it on every
page of the local site in
one simple step (Section 17.7). In fact, since a
Library item is a chunk of
HTML, the Museum could
actually replace the logo
with some text, a Flash
movie, or any other valid
HTML code.