isValid and pertinent subgraph

When performing revalidation, don't you have to obey
the pertinent subgraph of a vertex too? 

For example, let's say I have 

<bind id="x" ref="i/x" isValid="i/y > 10"/>
<bind id="y" ref="i/y" type="xsd:float"/>

<input bind="y"/>
<output bind="x"/>


Now, if I enter a value of '1' on the control bound to
Y, schema/facet validation will evaluate to true.
However, the control bound to X is now invalid since y
is less than 11.

It seems that if we are going to allow isValid to
happen before the entire recalculation, then isValid
must also be processes according a topological
sort/pertinent subgraph.

And what happens is isValid is dependent on a
calculated value from another binding? Since this
happens before the recalculate step, it will use the
old value, however, it may be that the control will
not be valid after the recalculate step.

For example:

X (current value 6)
Y isValid() = Z > 10 (current value, true)
Z calculate() = 2*X (current value, 12)

X is changed to 5. isValid() occurs on Y before Z is
recalculated, Y will return true. After recalculation,
Z will have a value of 10. Thus, the display will show
X=5, Y being valid, and Z being 10, which is an
invalid state, but no error message will be shown.


Am I missing something in the spec, or in the
Processing Model section wrong?



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Received on Friday, 19 October 2001 20:54:51 UTC