macaco
1
Hi.
I’ve been wondering if I can instantiate during execution, I have this
subclasses, but I don’t know how to do it by their name as a string.
This is what I mean:
class superClass
…
end
class subClass1 < superClass
…
end
class subClass2 <superClass
…
end
class caller
type = [‘subClass1’,‘subClass2’]
def create_class(var)
#instantiate class type[var]
newClass = type[var].new # ???
end
end
I don’t wanna do it with a case clause, cos I don’t know when I’m going
to
add more subclasses.
Any idea?
macaco
2
I’ve found this:
def create_class(var)
#instantiate class type[var]
foo = Object.const_get(type[var])
sub = foo.new
puts “#{sub.class}”
end
Works for me!
macaco
3
On Feb 6, 2008 8:32 PM, macaco [email protected] wrote:
I’ve found this:
def create_class(var)
#instantiate class type[var]
foo = Object.const_get(type[var])
sub = foo.new
puts “#{sub.class}”
end
Works for me!
So you’re not creating a class, really. You’re creating an instance of
already-defined classes. Right?
You can smash those down to one line and get rid of your holder
variable, if you like:
def create_thing var
sub = Object.const_get(type[var]).new
puts sub.class
end
I’m not a huge fan of holder variables, myself, but your mileage may
vary, of course.
Ben
macaco
4
On Feb 6, 2008, at 9:32 PM, macaco wrote:
I’ve found this:
def create_class(var)
#instantiate class type[var]
foo = Object.const_get(type[var])
sub = foo.new
puts “#{sub.class}”
end
Works for me!
Or you could do this:
def create_class klass
klass.new
end
create_class “subClass1” #=> #
BTW, can you have a class name that’s NOT a constant?
-------------------------------------------------------|
~ Ari
if god gives you lemons
YOU FIND A NEW GOD
macaco
5
macaco wrote:
type = [‘subClass1’,‘subClass2’]
def create_class(var)
#instantiate class type[var]
newClass = type[var].new # ???
end
If you change the first line into
type = [SubClass1, SubClass2] #without quotes
the above works as-is.
HTH,
Sebastian
macaco
6
On Feb 7, 2008, at 10:22 AM, fedzor wrote:
Or you could do this:
def create_class klass
klass.new
end
create_class “subClass1” #=> #
Whoops! This should be:
create_class subClass1
when you create a class, it assigns the class to the name you give it
--------------------------------------------|
If you’re not living on the edge,
then you’re just wasting space.