included module and scope confusion

[hmmm]

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I am confused about modules and scope.

Here is a module:

module Crumbs
MAX_CRUMBS =3D 10

def self.included(mod)
def cookies
return @cookies =3D=3D nil ? Hash.new : @cookies
end
end

def crumb_new( controller, action, params )
cstr =3D controller + "^" + action
if params !=3D nil && params.keys !=3D nil
params.keys.each {|p|
if params[p] !=3D nil
cstr << "^" << p << "^" << params[p]
end
}
end
return cstr
end

def crumb_add( bite )
cbs =3D @cookies
puts cbs.class
cbs =3D cbs[:rdf_crumbs]
if cbs =3D=3D nil
puts "crumb_add::cbs is nil!"
cbs =3D[bite]
else
puts "crumb_add::cbs is OK!"
cbs =3D cbs.split("|")
#don't add a redundant
if cbs.last =3D=3D bite
return
end
# add to
cbs << bite
# cap the cookie queue at 5 using fifo
if cbs.length > @@MAX_CRUMBS
cbs.delete_at(0)
end
end
crumbs_set( cbs )
end

def crumbs_set( mouthful )
cr =3D ""
mouthful.each { |m|
if cr =3D=3D ""
cr =3D m
else
cr << "|" << m
end
}
puts cookies.class
cookies[:rdf_crumbs] =3D cr
end

def get_crumbs()
crs =3D @cookies["rdf_crumbs"]
if crs =3D=3D nil
return []
else
return crs.split("|")
end
end

end
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D

Here is a unit test:
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D
class Bread
include Crumbs
def initialize
@cookies =3D Hash.new
end
end

class CrumbTest < Test::Unit::TestCase

attr :bread

def setup
@bread =3D Bread.new
end

def test_crumbs_simple
@params =3D Hash.new
bite =3Dbread.crumb_new( "test1", "test_action", @params )
bread.crumb_add(bite)
puts bite
bite =3Dbread.crumb_new( "test2", "test_action_2", @params )
bread.crumb_add(bite)
puts bite
bite =3Dbread.crumb_new( "test3", "test_action_3", @params )
bread.crumb_add(bite)
puts bite
assert bite =3D=3D "test3^test_action_3"
bites =3Dbread.get_crumbs()
puts bites.class
assert_equal bites.length, 3
end
end

Here is the output:
------------------------------------------
test cookies! on Bread
Hash
crumb_add::cbs is nil!
sets Hash with test1^test_action
has 1
test1^test_action
Hash
crumb_add::cbs is nil!
sets Hash with test2^test_action_2
has 1
test2^test_action_2
Hash
crumb_add::cbs is nil!
sets Hash with test3^test_action_3
has 1
test3^test_action_3
------------------------------------------

And:
------------------------------------------
Test::Unit::AssertionFailedError: <1> expected but was <3>.
test/unit/crumbs_test.rb:62:in `test_crumbs_simple'
------------------------------------------

I have tried different ways, but can't get the Correct Way to have a module
insert a variable into the Class that includes it. In this case it should
inject a @cookies hash, but in tests @cookies always gets reset to
Hash.new...

Excuse the inconsistencies in the code (towards @cookies) b/c I can't seem
to figure out the proper way.

So how do you add instance vars to a class from a module and how to
reference that attribute? Or is this not the Right Ruby Way?

I have a lot of confusion about modules... suppose its my java funk :/

Please point me to any more docs on modules besides the ruby-lang snippet.

-netcam

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[hmmm]

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Before I was mixing (include) Crumbs on the unit test class and I think
there was a name collision with the rails test_helper.rb file and @cookies
hence it got me all confused.

Ok here is what I did, and it seems simple. But a better way it seems woul=
d
to do it transparently to the subclass on the module, so if anyone knows
how, divulge. I don't want to have to declare the attr_reader :cookies on
the Class.

class Bread
include Crumbs

attr_reader :cookies

def initialize
@cookies =3D Hash.new
end
end

module Crumbs

# def self.included(mod)
# puts "test cookies! on #{mod}"
# def mod.cookies
# if @cookies =3D=3D nil
# @cookies =3D Hash.new
# end
# return @cookies
# end
# end

#----------------------------------------
#--------------begin/ cookie crumbs mixin
#----------------------------------------
MAX_CRUMBS =3D 10

def crumbs_clear
if @cookies !=3D nil and @cookies["rdf_crumbs"] !=3D nil
@cookies.delete "rdf_crumbs"
end
end

def crumb_new( controller, action, params )
cstr =3D controller + "^" + action
if params !=3D nil && params.keys !=3D nil
params.keys.each {|p|
if params[p] !=3D nil
cstr << "^" << p << "^" << params[p]
end
}
end
return cstr
end

def crumb_add( bite )
cbs =3D @cookies
puts cbs.class
cbs =3D cbs["rdf_crumbs"]
if cbs =3D=3D nil
puts "crumb_add::cbs is nil!"
cbs =3D[bite]
else
puts "crumb_add::cbs is OK!"
cbs =3D cbs.split("|")
#don't add a redundant
if cbs.last =3D=3D bite
return
end
# add to
cbs << bite
# cap the cookie queue at 5 using fifo
if cbs.length > MAX_CRUMBS
cbs.delete_at(0)
end
end

crumbs_set( cbs )
end

def crumbs_set( mouthful )
cr =3D ""
mouthful.each { |m|
if cr =3D=3D ""
cr =3D m
else
cr << "|" << m
end
}
puts "sets #{@cookies.class} with #{cr}"
if @cookies =3D=3D nil
@cookies =3D Hash.new
end
@cookies["rdf_crumbs"]=3Dcr
puts "has #{@cookies.keys.length}"
end

def crumb_del( bite )
crs =3D cookies[:rdf_crumbs]
if crs !=3D nil
crs =3D crumbs.split("|")
c2 =3D""
crs.each { |c|
if crs[c] !=3D bite
if c2 =3D=3D ""
c2 =3D c
else
c2 << "|" << c
end
end
}
cookies[:rdf_crumbs] =3Dc2
end
end

def get_crumbs()
crs =3D @cookies["rdf_crumbs"]
if crs =3D=3D nil
return []
else
return crs.split("|")
end
end

#----------------------------------------
#--------------end/ cookie crumbs mixin
#----------------------------------------
end

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[hmmm]

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Ok here is the final version...

Unit Test:
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D
class Bread
include Crumbs
def cookies
@cookies ||=3D Hash.new
end
def initialize
@cookies =3D Hash.new
end
end

class CrumbTest < Test::Unit::TestCase

attr :bread

def setup
@bread =3D Bread.new
end

# Simple add/delete/clear tests
def test_crumbs_simples
@params =3D Hash.new
bite =3Dbread.crumb_new( "test1", "test_action", @params )
bread.crumb_add(bite)
bite =3Dbread.crumb_new( "test2", "test_action_2", @params )
bread.crumb_add(bite)
bite =3Dbread.crumb_new( "test3", "test_action_3", @params )
bread.crumb_add(bite)
assert bite =3D=3D "test3^test_action_3"
bites =3Dbread.get_crumbs()
assert_equal bites.length, 3
bread.crumbs_clear()
bites =3Dbread.get_crumbs()
assert_equal bites.length, 0
bite =3Dbread.crumb_new( "test1", "test_action", @params )
bread.crumb_add(bite)
bread.crumb_del(bite)
bites =3Dbread.get_crumbs()
assert_equal bites.length, 0
end

def test_crumbs_params
bite =3Dbread.crumb_new( "test1", "test_action",
{"filter"=3D>"s`divx:divx"})
bread.crumb_add(bite)
bites =3Dbread.get_crumbs()
assert_equal bites[0], bite
end
end


And the crumbs module:
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D

module Crumbs
#----------------------------------------
#--------------begin/ cookie crumbs mixin
#----------------------------------------
MAX_CRUMBS =3D 10

public
def crumbs_clear
if cookies !=3D nil and cookies[:rdf_crumbs] !=3D nil
cookies.delete :rdf_crumbs
end
end

def crumb_new( controller, action, params )
cstr =3D controller + "^" + action
if params !=3D nil && params.keys !=3D nil
params.keys.each {|p|
if params[p] !=3D nil
cstr << "^" << p << "^" << params[p]
end
}
end
return cstr
end

def crumb_add( bite )
cbs =3D cookies[:rdf_crumbs]
if (cbs =3D=3D nil or cbs =3D=3D "") or (cbs.instance_of? Array and cbs=
length=3D=3D0)
cbs =3D[bite]
else
cbs =3D cbs.split("|")
#don't add a redundant
if cbs.last =3D=3D bite
return
end
# add to
cbs << bite
# cap the cookie queue at 5 using fifo
if cbs.length > MAX_CRUMBS
cbs.delete_at(0)
end
end

crumbs_set( cbs )
end

def crumbs_set( mouthful )
cr =3D ""
mouthful.each { |m|
if cr =3D=3D ""
cr =3D m
else
cr << "|" << m
end
}
cookies[:rdf_crumbs]=3Dcr
end

def crumb_del( bite )
crs =3D cookies[:rdf_crumbs]
if crs !=3D nil
crs =3D crs.split("|")
c2 =3D""
crs.each { |c|
if c !=3D bite
if c2 =3D=3D ""
c2 =3D c
else
c2 << "|" << c
end
end
}
cookies[:rdf_crumbs] =3Dc2
end
end

def get_crumbs()
crs =3D cookies[:rdf_crumbs]
if crs =3D=3D nil
return []
else
return crs.split("|")
end
end

#----------------------------------------
#--------------end/ cookie crumbs mixin
#----------------------------------------
end

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[Robert Klemme]

hmmm wrote:

I have tried different ways, but can't get the Correct Way to have a
module insert a variable into the Class that includes it. In this
case it should inject a @cookies hash, but in tests @cookies always
gets reset to Hash.new...

Of course because you assign it in initialize.

Two options:

1 Lazy init: You need to define cookies differently and access it always
through the getter method (attachment ex1.rb)

2 Init during constructor: you need to define #initialize in the module
and either leave initialize out of Bread or use super (attachment ex2.rb)

Module#included is completely wrong here as you do not want to do anything
to the class that uses the mod.

Excuse the inconsistencies in the code (towards @cookies) b/c I can't
seem to figure out the proper way.

So how do you add instance vars to a class from a module and how to
reference that attribute? Or is this not the Right Ruby Way?

I have a lot of confusion about modules... suppose its my java funk :/

Apparently.

Please point me to any more docs on modules besides the ruby-lang
snippet.

HTH

Kind regards

robert