| Author |
Adding instance methods to class at runtime
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| Jon A. Lambert 2005-08-29, 7:02 pm |
| I want to add instance methods to a class at runtine.
$ cat testcmds.rb
module Bar
def hello
puts "hello called"
end
end
class Foo
end
Foo.include(Bar)
Foo.new.hello
$ ruby testcmds.rb
testcmds.rb:10: private method `include' called for Foo:Class
(NoMethodError)
How can I do this?
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| David A. Black 2005-08-29, 7:02 pm |
| Hi --
On Tue, 30 Aug 2005, Jon A. Lambert wrote:
> I want to add instance methods to a class at runtine.
There's no other time to do it :-)
> $ cat testcmds.rb
> module Bar
> def hello
> puts "hello called"
> end
> end
>
> class Foo
> end
>
> Foo.include(Bar)
You can reopen the class and do the include:
class Foo
include Bar
end
or you can use send:
Foo.send("include", Bar)
David
--
David A. Black
dblack@wobblini.net
| |
| Kirk Haines 2005-08-29, 7:02 pm |
| On Monday 29 August 2005 2:52 pm, Jon A. Lambert wrote:
> I want to add instance methods to a class at runtine.
>
> $ cat testcmds.rb
> module Bar
> def hello
> puts "hello called"
> end
> end
>
> class Foo
> end
>
> Foo.include(Bar)
>
> Foo.new.hello
>
> $ ruby testcmds.rb
> testcmds.rb:10: private method `include' called for Foo:Class
> (NoMethodError)
>
> How can I do this?
irb(main):013:0* Foo.send(:include, Bar)
=> Foo
irb(main):014:0> Foo.new.hello
hello called
Kirk Haines
| |
| Jon A. Lambert 2005-08-29, 7:03 pm |
| David A. Black wrote:
> or you can use send:
>
> Foo.send("include", Bar)
>
Excellent Thank you.
I think my problem was scope then.
Here's what I be doing and it now works like a charm.
$ cat cmd1/cmd_bar.rb
module Command
def cmd_bar
puts "cmd_bar one called"
end
end
$ cat cmd2/cmd_bar.rb
module Command
def cmd_bar
puts "cmd_bar two called"
end
end
$ cat testcmds.rb
class Foo
end
def load1
cmds = Dir.glob("cmd1/cmd_*.rb")
cmds.each {|c| load(c)}
Foo.send(:include,Command)
end
def load2
cmds = Dir.glob("cmd2/cmd_*.rb")
cmds.each {|c| load(c)}
Foo.send(:include,Command)
end
f = Foo.new
load1
f.cmd_bar
load2
f.cmd_bar
$ ruby testcmds.rb
cmd_bar one called
cmd_bar two called
--
J. Lambert
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