Re: "importing" methods?


Think about Loose Coupling
	PerlMonks

Re: "importing" methods?

by pwagyi (Monk)

on Apr 28, 2019 at 12:41 UTC ( [id://1233075]=note: print w/replies, xml )

Need Help??

in reply to "importing" methods?

It looks like you've a singleton 'app' and it's been passed around to invoke methods. Normally this sounds like where DI is used? even thought DI would still require you to write $obj->method. Below idea could work. but I'm not really expert in the magical part of Perl. :)


sub _get_instance {
   ... init singleton if not created yet.
   return $app;
}
sub log {
# well there should be some easy way to somehow create function that f
+orwards to singleton
   my $app = &_get_instance;
   $app->log(@_);
}
[download]

Comment on Re: "importing" methods? Download Code

Replies are listed 'Best First'.

Re^2: "importing" methods?
by LanX (Saint) on Apr 28, 2019 at 13:09 UTC

Dependency injection

No it's not a singleton, there are (<10%) cases where I need more than one object.

Otherwise I'd use a normal module.

That's why I need a mechanism for the remaining 90% to use a normal Class like a singleton module.

My interpretation:

From a Java OOP point of view Perl's module/package architecture could be understood as Singleton classes and the import routine as the constructor and package vars as class/instance variables (singleton means class=instance)

Lexical scoping of a modules effects are crucial to avoid global conflicts.

These things are hard to discuss because of little incompatibilities between languages.

Cheers Rolf
_{(addicted to the Perl Programming Language :)

Wikisyntax for the Monastery
FootballPerl is like chess, only without the dice}

[reply]

In Section Seekers of Perl Wisdom