Dear Arthur,

this is a known problem area, already on our todo list.

What you are defining is an user-defined, slot-specific parameter type.

In nx, object parameters are closer to the general parameter handling (e.g. method parameters) than to accessors. The parameters provide a rich set of configuration options (value checkers, multiplicity, requiredness, ...). NX comes with several built-in checkers/converters, which can be extended with user-defined (scripted) checkers (see [1]).

For value checkers, a developer can decide, for which kind of parameter a checker should be applicable. When a value-checker is defined on the class nx::Slot, then this checker can be used for method parameters in the same way as for object parameters (see [2]).

[1] http://next-scripting.org/docs/2.0b2/doc/nx/tutorial/index1#_value_constrain... [2] http://next-scripting.org/docs/2.0b2/doc/nx/tutorial/index1#_slot_classes_an...

Your example can be defined with a scripted checker as shown below.

====================================================== nx::Class create Foo { :property bar { :type "bar" :method type=bar {name value} { puts stderr "assign called for $name $value" } } }

set foo [Foo new] $foo bar "test" Foo new -bar "test" ======================================================

The checker is called here - as expected - twice.

In the more general case below, the converter is defined on nx::Slot, therefore applicable for every parameter (e.g. for property "bar" and for the method "abrakadabra").

====================================================== nx::Slot public method type=baz {name value} { puts stderr "assign called for $name $value" }

nx::Class create Baz { :property bar:baz :public method abrakadabra {x:int y:baz,1..n} { return $x-$y } }

set baz [Baz new] $baz bar "test" $baz abrakadabra 1 {a b c} Baz new -bar "test" ======================================================

Since y of abrakadabra has defined the multiplicity 1..n, the checker is called for every single value (in the snipped above 5 times).

The new parameters are more powerful and general than the xotcl-style "assign" method; so i tend to believe the latter is obsolete. Some cleanup is here still necessary.

-gustaf neumann

On 26.01.12 12:06, Arthur Schreiber wrote:

Hi everyone,

When assigning an object's property using object parameters, the assign method of that property does not get called. Is that a bug or intended behaviour?

See the following code:

package require nx

nx::Class create Foo { :property bar { :public method assign { object property value } { puts "assign called for: $object $property $value" } } }

set foo [Foo new] $foo bar "test"; # assign method of the bar property is called

Foo new -bar "test"; # assign method of the bar property is _not_ called

Kind regards, Arthur _______________________________________________ Xotcl mailing list Xotcl@alice.wu-wien.ac.at http://alice.wu-wien.ac.at/mailman/listinfo/xotcl