Derived-class initialization

[Bryan Richardson]

Hello all,

I'm having some trouble with extending an existing Ruby class in order
to add functionality. Here's some example code:

class Graph
....
....
def subgraph(*args)
graph = self.new
....
....
return graph
end
end

class AwesomeGraph < Graph
....
....
def do_something
....
....
end
end

g = AwesomeGraph.new
a = g.subgraph(g.nodes)
a.do_something // ERROR! No Graph#do_something exists!

I was hoping 'self.new' would take into account the derived class used
upon creation, but it doesn't.

Any suggestions?

 

[James Coglan]

[Note: parts of this message were removed to make it a legal post.]

Hello all,

I'm having some trouble with extending an existing Ruby class in order
to add functionality. Here's some example code:

class Graph
....
....
def subgraph(*args)
graph = self.new
....
....
return graph
end
end

This looks suspect, 'self' in this method looks like it will refer to the
Graph instance, not the Graph class. Try self.class.new instead.

 

[Bryan Richardson]

Yep... that worked.

--
Thanks!
Bryan

This looks suspect, 'self' in this method looks like it will refer to
the
Graph instance, not the Graph class. Try self.class.new instead.