Tips & Tricks
Customize the style of appended alerts
by defining the targetalert class in userContent.css.
Images for appended alerts have the following two attributes:
style="display: inline !important; margin-left: 5px; margin-bottom: -3px; border: 0px none;"
targetalert, you can override the default style
for the image by editing your userContent.css file.
If you have not worked with userContent.css before,
then you probably need to create this file. To learn how and where to create this file, see
the instructions for creating userContent.css for
or Mozilla on mozilla.org.
Alternatively, you can install the chromEdit
extension (which works with both Firefox and Mozilla) that lets you edit userContent.css
and other profile-related files without the hassle of figuring out where they are stored on disk.
Once you have created userContent.css, you can define whatever CSS you like
for appended alert images. The following CSS could be used to ensure that alerts display with a white background:
background-color: #ffffff !important;
Because TargetAlert icons have transparent backgrounds, their background color will be that
of the current web page; however, the above customization will guarantee that the background
of the image will always be white. This can be helpful on web pages whose background color makes
the alert difficult to see.
Another option is to add a thin border around the image so that it is more visible while
still using the page's natural background color. This can be achieved by using the following customization:
border: 1px solid #ffffff !important;
On MS Windows, use the moz-icon: protocol
to get the icon associated with a file extension.
When defining your own alerts for a particular file extension, you may want to
use the same icon that Windows already uses when displaying that file in Windows applications such as Explorer.
Both Firefox and Mozilla make it possible to access this icon (on Windows only)
moz-icon: protocol. For example, typing the following into the
address bar will display the icon that Windows displays next to a file whose name ends in
To get the default icon for other filetypes, substitute
pdf with the desired file extension.
To change the size of the icon, change the value of the
size parameter. Although any number
could be entered, I believe that 16 and 32 are the only valid values; if a different value is entered,
then 16 or 32 is used, whichever is more appropriate. As I have yet to find any documentation
moz-icon: protocol on mozilla.org, the information I have here is only the results of my
own experimentation with the protocol and should not be treated as official documentation.