Re: Non-eventable and other thoughts


After today's talks, I am still wondering whether besides the backward
compatibility requirements, we need that no-events mode.

I think one of the arguments that was mentioned for the initial
rationale of this feature was that as a form author having event
listeners say on a group around something that is not relevant, you
might not expect events to be dispatched purely based on the fact that
there is some kind of expectation that something non-relevant is kind
of disabled.

Which would be fine, except for the other requirement which is that
the user interface updates values. But if you don't have events, that
requirements of the UI updating properly fails in many cases. Consider
for example the following scenario:

<xf:group ref="node-which-can-be-non-relevant">
    <xf:input ref="amount">
        <xf:setvalue ev:event="xforms-value-changed" ref="../tax"
value=". * 0.1"/>
    <xf:output ref="tax"/>

Basically, any user interface that uses events to update other aspects
of the user interface would fail when non-relevant. So the no–events
mode would only make sense situations where the UI is not defined this
way, which is a big restriction.

The bottom line is that we might have to discourage form authors from
using this mode or things might not work as expected, and that makes
it an unsatisfying feature.

I think, again besides the backward compatibility requirements, that a
stronger case must be made for the no–events option.


Received on Friday, 5 November 2010 18:25:09 UTC