A Swedish wolf in Norway

The first technical preview of Opera 9 was published today, and it contains the beginnings of support for a feature that has often been requested in our various wish-list forums, namely site-specific preferences. I have been working on this feature for quite some time now. Opera 9 preview is the first publicly available version where this support is available, and now I finally can step forward and say yes, we are indeed working on that.

Site-specific preferences is exactly what it says, the possibility to set preferences specifically on a site. Opera 8 had a preview of this in its ua.ini, which would override the User-Agent identification on different sites. The support for that file has now been withdrawn, and the setting is instead integrated into the general settings file (you can find the name of it by going to opera:about).

To set the User-Agent to always show Opera when visiting www.opera.com (this is the default setting that is downloaded when you select Help → Check for new version):

[Overrides]
www.opera.com

[www.opera.com]
User Agent|Spoof UserAgent ID=1

As you can see from the example, you need to do two things: First, you need to add a section called [Overrides] that lists the hosts for which the overrides are available. Second, you need to add a preference section for that host name where you add the appropriate setting. Since settings are normally identified by a section (here [User Agent]) and a key (here Spoof UserAgent ID) you need to give both, you do that by separating them with a vertical bar character (|). See the ini documentation for more information on the names used in the preferences file. You can also find the list of supported preferences by using the new opera:config interface.

Not all preferences are supported for overrides (yet). Some will not be (it doesn't make sense to switch UI languages when going to a different site), but more are planned. Here are some that are (at least partially) supported that you can play around with:

• User Agent|Spoof UserAgent ID to set the User-Agent string ("identify as").
  
• Extensions|Frames to enable/disable frames.
  
• Extensions|Plugins to enable/disable plug-ins.
  
• User Prefs|Enable Referrer to enable referrer logging on a specific site. Please note that it is the referring page (i.e the one you are leaving) that decides whether referrer should be enabled or not. This can be useful if you don't normally like sending referrer, but need to access some over-paranoid page that requires them.
  
• Sounds|Enabled to let some pages notify you with sound, while keeping others quiet.
  

There are more supported than are listed here, see also Håvard's blog entry on the subject. Feel free to play around with it. Better documentation will come later, and we of course plan to make them available from the user interface...