Firefox Hacks [Electronic resources] نسخه متنی

1.2. Get Oriented

Before starting our journey, there are a few things you need to know:
how to find Firefox files, how to install an extension, and how to
set a preference. You don''t need this information to
read a web page, but it''s vital for most of the
hacks in this book.

1.2.1. Finding Firefox Files After Installation

After installation, Firefox puts its
files in two important directories. The first is the
install
area, also known as the application
area, which gets the general-purpose bits,
such as the Firefox programs themselves. The second is the
profile
area, which gets user-specific information,
such as bookmarks. Table 1-1 lists the default locations of
these two areas on different operating
systems.

Feel free to have a (careful) look around in these directories.

1.2.2. Installing an Extension

Extensions
are small enhancements to Firefox that are added optionally and
separately to the main browser install. Just as plug-ins, such as
Apple''s QuickTime, enhance the display of web pages
with special content, extensions enhance the display of
Firefox''s user interface with extra commands and
extra windows. You install an extension when you need an extra
feature.

You can install extensions from the official http:// web site or from
any web site that offers a .xpi file. Such files
almost always hold one extension each.

If you choose to install an extension, you are acting like a power
user rather than a beginner, so you have to use your judgment to
decide what extensions will be useful to you. It''s
no use complaining that Firefox is too complicated if you have 10 or
20 extensions installed. Just remove them and resimplify your life.

1.2.2.1 Installing from

The Advanced Search Button
extension (found in the Search Tools category at http://) is a harmless
extension to experiment with. Here''s how to get it.

After browsing to it on the update site, click on the matching
install link. Sometimes there''s a brief pause, and
then Firefox presents an acknowledgement window. After another brief
pause, Firefox enables the buttons in that window, asking you whether
to proceed. In this case, go ahead.

At this point, most extensions are still unsigned, just as the dialog box reports. Although the update site has excellent trust credentials, the extension itself has no signature. Extensions have some credentials, though, because they''ve been through some checks before the update site makes them available. Ultimately, though, it''s up to you to believe whether the update site and the extension provider are persons of goodwill. This is true for any download.

Once the user agrees, Firefox downloads and installs the extension.
If you choose ToolsExtensions, you''ll see
it there in the list, but disabled and unusable (click on it and
everything is grayed out). Shut down Firefox completely and start it
up again. Again, look under ToolsExtensions.
You''ll see that the extension is now enabled and
ready to use.

The sample extension, Advanced Search Button,
doesn''t change the Firefox user interface much at
all. All it does is offer you a new toolbar icon. Choose
ViewToolbarsCustomize... to see the list of icons
available. Scroll down and you''ll see
there''s a new ASB icon there. Drag it to the
navigation toolbar with the mouse. Finally, close the icon window.
You can now click on the ASB button or the small triangle next to it.
If you put a word in the search box and click the ASB button, the
Advanced Search Button extension will search for that word in the
currently displayed page.

1.2.2.2 Installing from elsewhere

By default, the
Mozilla Update site (Figure 1-1 shows this complaint
for the version of the EditCSS extension that is available at
http://editcss.mozdev.org.

Figure 1-1. Extension warning info bar for untrusted windows

If you click the Edit Options... button, a dialog box appears (shown
in Figure 1-2), where you can add the web site to a
whitelist of trusted sites. That has to be done at your discretion.

Figure 1-2. Extension web site whitelist dialog box

If the web site is added and the dialog box acknowledged,
you''re then sent back to the extension installation
page. You have to click the extension''s link a
second time to restart the installation process, with trust now in
place. From here, installation proceeds as explained for the Mozilla
Update case.

1.2.3. Setting a Preference with

A
preference
is a user choice that affects
how Firefox runs. Firefox has
hundreds of preferences. The Firefox Options Dialog box, under
ToolsOptions (Windows), EditPreferences
(Unix/Linux), or FirefoxPreferences (Macintosh) is the way
to set common preferences. In general, though, the page shown by the
special

Modify

Enter a new preference
value.

Toggle

Change TRue to false or
false to
TRue.

Reset

Remove any change made to the standard
value.

To add a new preference, choose the New context menu option and
follow these guidelines:

Choose the type of information the preference must hold. Use Integer
for numbers and Boolean for preferences that are
true or false. Otherwise, use
String.

Fill in the preference name and value in the small windows that
appear. Type carefully, because there is no syntax checking.

After setting the preference, it appears in bold (unless you reset
it). The