- From: Matthew Thomas <mpt@myrealbox.com>
- Date: Thu, 17 Jun 2004 19:43:52 +1200
On 17 Jun, 2004, at 4:10 AM, Ian Hickson wrote: > > On Fri, 11 Jun 2004, Christian Schmidt wrote: > ... >> The custom validation could be done in onchange or oninput, but that >> may turn out to be too often or too rare. > > Why? It would be too often in any situation where there are three or more variables competing for a shared resource. If there were two, you could automatically adjust the one that wasn't being altered to match; but if there's three or more you can't. Example 1: | | Rank the candidates 1, 2, 3 in order of preference: | [ 2] Sonja Gonzalez | [ 1] Hubert Appleton | [ 3] Tracy Ming | Here validation would consist of ensuring that (a) you'd only used 1, 2, and 3, and (b) you hadn't entered the same number twice. But if such validation was done onchange it would be impossible to change anything, because getting from any valid state to any other valid state necessarily passes through an invalid state. (A more convenient, but slightly less obvious, alternative to the above text fields would be a 3*3 grid of radio buttons. But the same validation problem would apply.) Example 2: | | The safari will last for 7 days. How many days do you | want to spend on each activity? | | Hippo wrestling: [ 2] ====V========== | Meerkat watching: [ 4] ========V====== | Wildebeeste racing: [ 1] ==V============ | 0 1 2 3 4 5 6 7 >> If validity is the sum of several ERROR_* constants including >> ERROR_USER_DEFINED and the UA only displays the error message related >> to one constant at a time, it would probably make sense to display >> the one set with setCustomValidity() first (it would probably be more >> specific than the standard messages). I don't know whether this >> behaviour should be required by UA's or even suggested in the spec. > > Yeah. It's up to the UA. > ... Ideally UAs should be able to display all error messages at once, under/beside the relevant control(s) in the page itself, like current forms validated server-side do. Displaying a stream of alert boxes would be a degradation from that. -- Matthew Thomas http://mpt.net.nz/
Received on Thursday, 17 June 2004 00:43:52 UTC