On balance, I'd rather not implement it. The default behaviour in all browsers is to open in the current window, however this is easily overridden: for example in Safari by holding down the Command key before clicking, or in Chrome or Firefox on Windows by holding down the Control key, or right-clicking and selecting 'open in new tab'. I think it's best to make the site work in the conventional, expected, way, and leave people to control the behaviour if they wish to, rather than give them non-default behaviour that they can't control.
an IARC request.
mailed to IARC for comment:
On balance, I'd rather not implement it. The default behaviour in all browsers is to open in the current window, however this is easily overridden: for example in Safari by holding down the Command key before clicking, or in Chrome or Firefox on Windows by holding down the Control key, or right-clicking and selecting 'open in new tab'. I think it's best to make the site work in the conventional, expected, way, and leave people to control the behaviour if they wish to, rather than give them non-default behaviour that they can't control.