[webkit-dev] Changes to DOM related exceptions

Erik Arvidsson arv at chromium.org
Wed Dec 5 12:29:44 PST 2012

The specs for DOM related exceptions has changed a bit over the last
few years. These changes have been made to simplify things, both for
end users and implementers. Fortunately for the spec writers no two
browsers agreed on the behavior, so end users could not depend on the
details of the old specs. Unfortunately for us, we implemented things
according to the old spec.

So what changed? A lot of the new specs just throw DOMExceptions
(instead of more specialized exceptions like RangeException). Also,
new error types have a "code" property of 0.

What might break? Code that does instanceof checks or accesses removed
exception constructors.

This should be a low risk since, like previously mentioned this never
worked cross browser. For Apple dashboard widgets, this should still
be a safe change since checking the type of an exception is hardly
ever done (we don't even have tests covering this).


More information about the webkit-dev mailing list