Beginning ASP.NET 4.5 in CSharp and VB Opsylum

An Introduction to jQuery x 391
How It Works
To see how it works, take a look at the Scripts folder in your
Solution Explorer. You should see an item called jquery-1.7.2.js,
shown in Figure 11-3. Remember, a new version may have been
released since this book was written so your version numbers may
be different. During installation, NuGet added three jQuery-related
JavaScript files to your Scripts folder (which it would have created
if it didn’t exist.) In addition, it kept track of the installed packages
in a file called packages.config that has been placed in the root of
your website and created a packages folder to store a local copy of
FIGURE 11-3
the downloaded packages. Depending on your settings, this location
could differ, but most likely it’s located in a folder named after your site in Documents\Visual Studio
2012\Projects.
These three .js files all serve a different purpose. The file jquery-1.7.2.js contains the core jQuery
code in an uncompressed format. This means you can read its code and use it for debugging purposes
in cases where you need to see what code the library executes. The file jquery-1.7.2.intellisense
.js contains the documentation for the code in the jQuery library that is used in the IntelliSense lists
and documentation pop-ups. You see how this works later in this chapter. Finally, the fi le jquery-
1.7.2.min.js is the core jQuery library in a compressed format. This is the file you’ll use in your website
because it has the smallest size and is thus the quickest to download.
Now that the jQuery library has been added to the website, the next step is determining where to
use it. Because the jQuery library adds to the size of your web pages, it should be a deliberate choice
whether or not you include it in your site.
Choosing the Location for Your jQuery Reference
To include jQuery in your website, you have a couple of options:
‰ Add a reference to the jQuery library in just the web pages or user controls that require it.
‰ Add a reference to the jQuery library in the master page of your site so it’s available in
all pages.
Both methods have their own advantages and disadvantages. Adding a reference to the jQuery
library in just the pages that need it helps keep the size of your pages down a bit. When your users
browse only to pages without jQuery, they’ll never have to download the library file, saving them
some bandwidth. Note that once they’ve visited a page that does reference the library, the browser
will cache a copy of it, removing the need to download it again on subsequent visits to pages.
Adding the reference to jQuery in the master page of your site is quite convenient, because all pages
based on this master page automatically get access to the jQuery functionality. However, this results
in a small performance hit on the first page of your site because the library needs to be downloaded
from the server. This is the option used in the Planet Wrox website.