Adding instance methods to class at runtime

[Jon A. Lambert]

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?

 

[David A. Black]

Hi --

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

 

[Kirk Haines]

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.sendinclude, Bar)
=> Foo
irb(main):014:0> Foo.new.hello
hello called


Kirk Haines

 

[Jon A. Lambert]

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.sendinclude,Command)
end

def load2
cmds = Dir.glob("cmd2/cmd_*.rb")
cmds.each {|c| load(c)}
Foo.sendinclude,Command)
end

f = Foo.new

load1
f.cmd_bar

load2
f.cmd_bar

$ ruby testcmds.rb
cmd_bar one called
cmd_bar two called