array of objects within an object

[DiesIrae]

Hi all,

I am storing an array of objects within another object, but am not
sure how to print the values of the array out. When I do an
Port.inspect, it gives me something like this:

#<Port:0x4021de58 @state=[#<State:0x4021dca0 @state="1">,
#<State:0x4021d8f4 @state="2">], @protocol="tcp",
@owner=[#<Owner:0x4021d9a8 @name="11">, #<Owner:0x4021d854
@name="12">>


But when I do a Port.print_port, defined as

def print_port
"Port: #{@protocol}, #{@state}, #{@owner} "
end

it prints:

Port: tcp, #<State:0x4021dcc8>#<State:0x4021d8cc>,
#<Owner:0x4021d9d0>#<Owner:0x4021d82c>

So, How do I address the object with the ID of #<State:0x4021dcc8>,
and print out its constituent values?

thanks for any help.

Dan

 

[Austin Ziegler]

I am storing an array of objects within another object, but am not
sure how to print the values of the array out. When I do an
Port.inspect, it gives me something like this:

[minor editing for clarity]

#<Port:0x4021de58
@state=[#<State:0x4021dca0 @state="1">,
#<State:0x4021d8f4 @state="2"> ],
@protocol="tcp",
@owner=[#<Owner:0x4021d9a8 @name="11">,
#<Owner:0x4021d854 @name="12">>

But when I do a Port.print_port, defined as

class Port

def print_port
"Port: #{@protocol}, #{@state}, #{@owner} "
end

end

Right. What you're doing here is implicitly calling #to_s on each of
your values through the use of interpolation. Thus, you have two
issues:

1. Neither State or Owner define #to_s values. This will harm
readability. However, even if you do:

class State
def to_s
"State: #{@state}"
end
end

class Owner
def to_s
"Owner: #{@name}"
end
end

you'll end up getting:

Port: tcp, State: 1State: 2, Owner: 11Owner: 12

Thus, you need to change your Port #to_s and #print_port definition
to:

class Port
def print_port
to_s
end

def to_s
%Q|Port: #{@protocol}, [#{@state.join(", ")}], [#{@owner.join(", ")}]|
end
end

With this, you'll get:

Port: tcp, [State: 1, State: 2], [Owner: 11, Owner: 12]

-a

 

[Markus]

I am storing an array of objects within another object, but am not
sure how to print the values of the array out. When I do an
Port.inspect, it gives me something like this...:

If you are dealing with modest sized, non-recursive structures, you can
throw together something like this:

class Object
def pretty(indent = '')
if instance_variables.length > 0
self.class.to_s+":\n"+(instance_variables.collect { |v|
indent+v+':
'+instance_variable_get(v).pretty(indent+' ')
}.join("\n"))
else
self.class.to_s
end
end
end

class Numeric
def pretty(indent = '')
to_s
end
end

class String
def pretty(indent = '')
inspect
end
end

class Array
def pretty(indent = '')
super + "[\n"+
collect{ |v|
' '+indent+v.pretty(indent+' ')
}.join(",\n") + "\n"+
" " + indent+"]"
end
end

class My_class
attr_accessor :test,:aa
def initialize
@test = "goo"
@aa = [nil,true,8]
end
end

print ["test",7,My_class.new].pretty,"\n"


Not "production quality" but quick & easy for debugging purposes, and
easy to extend (and, to some extent, self-extending).

-- MarkusQ

 

[Brian Sheehan]

Hello,

I think you need to define to_s methods for your
Port, State and Owner classes. These to_s methods
should return a string representation of the class
they belong to (e.g. the state of the current object's
instance variables). The Object#inspect method will
then call these methods when invoked, instead of
calling Object#to_s

hope this helps,

Brian

Hi all,

I am storing an array of objects within another
object, but am not
sure how to print the values of the array out. When
I do an
Port.inspect, it gives me something like this:

#<Port:0x4021de58 @state=[#<State:0x4021dca0
@state="1">,
#<State:0x4021d8f4 @state="2">], @protocol="tcp",
@owner=[#<Owner:0x4021d9a8 @name="11">,
#<Owner:0x4021d854
@name="12">>


But when I do a Port.print_port, defined as

def print_port
"Port: #{@protocol}, #{@state}, #{@owner} "
end

it prints:

Port: tcp, #<State:0x4021dcc8>#<State:0x4021d8cc>,
#<Owner:0x4021d9d0>#<Owner:0x4021d82c>

So, How do I address the object with the ID of
#<State:0x4021dcc8>,
and print out its constituent values?

thanks for any help.

Dan

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