Value changes upon instance replacement
From W3C XForms Group Wiki (Public)
Revision as of 15:19, 25 February 2010 by Nvandenb
Erik's note: this is part of a larger "improved UI events" feature.
Original post from ErikBruchez:
Date: Fri, 18 May 2007 17:16:25 +0200 To: firstname.lastname@example.org Subject: Value changes upon instance replacement From: "Erik Bruchez" <email@example.com> Cc: firstname.lastname@example.org All, At the moment, I don't think this is clearly specified to happen. Use case: 1. <xforms:input ref="name"> 2. The instance containing "name" is replaced. 3. Section 11.2 specifies that a refresh must take place. However, no node of the new instance is marked as having changed as I understand it. 4.3.4 says "If the value of an instance data node was changed, then the node must be marked for dispatching the xforms-value-changed event.". But in this case, the value of the node hasn't changed because the node is just freshly created from the instance replacement. 4. Consequence: no xforms-value-changed is fired. This behavior is very non-intuitive because you can replace an instance under controls' feet and while the control may update their values in the UI, no xforms-value-changed is fired. This means that you cannot reliably use events to determine if the value of a control has changed or not. I think that this should be possible, or the usefulness of value-changed-events is greatly reduced. -Erik