Re^2: Dynamically Creating (and Calling) Object Methods

Thanks for the reply. That does make sense. After some googling I tried this approach in BigDB::new()...

     # $cmd = "method1"
     eval {
                no strict 'refs';
                *{'BigDB\::$cmd'} = makeCommandSub($CMDS->{$cmd});
            } or die "Can't modify the symbol table: $!";
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...but this does not seem to result in a usable $myDB->method1() as I would like. ("Cannot locate method "method1" via package BigDB....")

So next I tried hard-coding the new symbol name like so:

*BigDB::method1 = makeCommandSub(...);
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and that works! So I just need to know how to use a string as part of the symbol reference. More clues? :-)

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Re^3: Dynamically Creating (and Calling) Object Methods by gaal (Parson) on Jan 07, 2007 at 10:03 UTC
First, unrelated to your main task: you don't need to say `eval {...} or die $!`, for several reasons. The first is that if it throws an exception, you can probably use the original exception :) Second, the `or` there is dangerous unless `makeCommandsSub` is guaranteed to return a true value; the valuation of an eval is (like any other block of Perl 5) its last evaluated thing. So `eval { 0 } or die "this dies, but not because of an exception in the i +nner block!";` [download] Finally, $! is wrong in this case, you need $@ for the exception. But to your real question: You said 'BigDB\::$cmd'. But because of the single quotes, this creates literally a '$cmd' package in BigDB's symbol table! (Check by printing `keys %BigDB::`.) The correct code is `{"BigDB::$cmd"} = ...` [download] You probably got the backslash from code that used a variable containing the caller, where it's needed to make Perl not think you're talking about a fully qualified variable: `{"$caller\::methodname"} = ...` [download]	[reply] [d/l] [select]
Re^3: Dynamically Creating (and Calling) Object Methods by ysth (Canon) on Jan 07, 2007 at 17:57 UTC
'BigDB\::$cmd' is single-quoted, so creates a method named `$cmd` in package `BigDB\` instead of a method named `method1` in package `BigDB`. Try double quotes (where the backslash becomes harmless though unnecessary).	[reply] [d/l] [select]