note
gmax
<p>Use the <u>can</u> method (it's a method of the [UNIVERSAL ]package, so every class in Perl has access to it).</p>
<code>
#!/usr/bin/perl
use strict;
use warnings;
package Communications;
sub SendMessage {
my $packages = shift;
my $msg = shift;
for (@$packages) {
if ($_->can('ReceiveMessage') ) {
$_->ReceiveMessage($msg);
}
else {
print "$_ can't ReceiveMessage\n"
}
}
}
sub ReceiveMessage {
print __PACKAGE__, "::ReceiveMessage('$_[1]')\n";
}
package Second;
sub ReceiveMessage {
print __PACKAGE__, "::ReceiveMessage('$_[1]')\n";
}
package Other;
sub nothing {
print "\n";
}
package main;
my @packages = qw(Communications Other Second);
Communications::SendMessage( \@packages, 'hello');
__END__
output:
Communications::ReceiveMessage('hello')
Other can't ReceiveMessage
Second::ReceiveMessage('hello')
</code>
<div class="pmsig">
<div class="pmsig-127116">
<pre>
_ _ _ _
(_|| | |(_|><
_|
</pre>
</div>
</div>
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