My first explanation for this behavior from Monday was wrong ... sorry for that. In fact, the filter would filter maa ... if it is called directly (try
a maa
at the end of the program.) The reason why it is not filtered is that an active filter does not filter calls issued by itself ... a filter is active in its pre- and post part, but not during next, and only for the current object. That is, if the filter does call a method on the same object, this method call will not be filtered by that filter. If there wouldn't be such a protection, there would nearly always be endless loops during filter calls that call other methods. (Because the called filter would then issue another call to be filtered and so on and so forth). A solution for the problem below would be to provide two filters that do not mutually exclude each other, like:
A instproc af args { set method [self calledproc] if {[[self] exists delegate]} { set del [[self] set delegate] if {$method != "ma"} { return [eval $del $method $args] } } next } A instproc bf args { set method [self calledproc] if {[[self] exists delegate]} { set del [[self] set delegate] if {$method == "maa"} { return [eval $del mbb] } } next }
A instfilter {af bf}
--uwe
Can anyone assist me in explaining what is happening here?
#Code: Win 98 version 0.91; got same problem with ver 0.85 3 months ago.
Class A -parameter {delegate}
A instproc af args { set method [self calledproc] if {[[self] exists delegate]} { set del [[self] set delegate] if {$method == "maa"} { return [eval $del mbb] } if {$method != "ma"} { return [eval $del $method $args] } } next }
A instfilter {af}
A instproc ma args { puts "method ma of A" }
Class B B instproc bf args { set sender [self callingobject] set method [self calledproc] puts "method is: $method" if {$method == "mb"} {
return [eval $sender maa]} next }
B instfilter bf
B instproc mb args { puts "method mb of B" }
B instproc mbb args { puts "method mbb of B" }
B b A a a delegate b #a ma ; #works ok a mb
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