Intra-module method calls

Ruby
1

I have a module named X

module X

end

I would like to call one method from another in my module.

If I do

public
def method1
…
method2
end

private
def method2
…
end

why doesn’t this work? Is it because this isn’t a class and the
“private” keyword isn’t meaningful?

Thanks,
Wes

2

Sorry, I wasn’t clear enough - my question is why does the call to
method2 from method1 fail with a

undefined method `method2’ for X:Module

error?

Thanks,
WG

Wes G. wrote:

I have a module named X

module X

end

I would like to call one method from another in my module.

If I do

public
def method1
…
method2
end

private
def method2
…
end

why doesn’t this work? Is it because this isn’t a class and the
“private” keyword isn’t meaningful?

Thanks,
Wes

3

Wes G. wrote:

Sorry, I wasn’t clear enough - my question is why does the call to
method2 from method1 fail with a

undefined method `method2’ for X:Module

Is the following what you are doing ?

irb(main):007:0> module X
irb(main):008:1> public
irb(main):009:1> def method1
irb(main):010:2> “method1” + method2
irb(main):011:2> end
irb(main):012:1> private
irb(main):013:1> def method2
irb(main):014:2> “method2”
irb(main):015:2> end
irb(main):016:1> end
=> nil
irb(main):017:0> class A
irb(main):018:1> include X
irb(main):019:1> end
=> A
irb(main):020:0> A.new.method1
---------------------^^^^^^^^^^---------------
irb(main):021:0> A.new.method1
=> “method1method2”

Because the above should work just fine. If the above is not what you
are seeing, please post the code so we can better help.

Zach

4

I just want to have some utility methods for use by my app.
The code below works.
Notice the calls to add_default_path in the other two methods.

My question is: why do I have to qualify the name of add_default_path
with ESimplyUtil since no external code is calling that method? Why
can’t I just have

def add_default_path
end

?

Thanks,
WG

===================

Here’s my module:

module ESimplyUtil
public
def ESimplyUtil.validate_and_format_url(in_url)
begin
url = URI.parse(in_url)
rescue
raise(“This is not a valid URL”)
end

#If the URL is valid HTTP URL, default the path if necessary
#If the URL is generic make it into an HTTP URL
# Get the host - match the first set of non-/ characters
# Get the path - match all of the characters including the first

slash
#If the URL is a valid non-HTTP URL, then it’s an error.
if (url.instance_of?(URI::HTTP))
url = add_default_path(url)
elsif (url.instance_of?(URI::Generic))
if (((url.scheme != nil) && (url.scheme != “http”)) ||
(url.path.nil?) || (url.path == ‘’))
raise(“This is not a valid URL”)
else
port = 80
host = url.path.match(/[^/]+/)[0]
path_match = url.path.match(//(.*)/)
if (path_match.nil?)
path = ‘/’
else
path = path_match[0]
end

    url = URI::HTTP.new('http', nil, host, 80, nil, path, nil, nil,

nil)
end
elsif (! url.instance_of?(URI::HTTP))
raise(“This is not a valid URL”)
end

url

end

public
def ESimplyUtil.get_URL(myURL)
url = URI.parse(myURL)
url = add_default_path(url)
req = Net::HTTP::Get.new(url.path)
res = Net::HTTP.start(url.host, url.port) {|http|
http.request(req)
}

res

end

private
def ESimplyUtil.add_default_path(url)
if ((url.path == ‘’) || (url.path.nil?))
url.path = ‘/’
end

url

end
end

5

“W” == Wes G. [email protected] writes:

W> module ESimplyUtil

[…]

W> private
W> def ESimplyUtil.add_default_path(url)

Be carefull, ruby will not do what you think

moulon% cat b.rb
#!/usr/bin/ruby
module A
private
def self.a
end

class << self
private
def b
end
end
end

[“a”, “b”].each do |m|
puts “#{m}() private ? #{A.private_methods.include?(m)}”
puts “#{m}() public ? #{A.public_methods.include?(m)}”
end

moulon%

moulon% ./b.rb
a() private ? false
a() public ? true
b() private ? true
b() public ? false
moulon%

Guy Decoux

6

So, in normal language, does that mean that “private” is not meaningful
within the context of a module?

Thanks,
Wes

ts wrote:

“W” == Wes G. [email protected] writes:

W> module ESimplyUtil

[…]

W> private
W> def ESimplyUtil.add_default_path(url)

Be carefull, ruby will not do what you think

moulon% cat b.rb
#!/usr/bin/ruby
module A
private
def self.a
end

class << self
private
def b
end
end
end

[“a”, “b”].each do |m|
puts “#{m}() private ? #{A.private_methods.include?(m)}”
puts “#{m}() public ? #{A.public_methods.include?(m)}”
end

moulon%

moulon% ./b.rb
a() private ? false
a() public ? true
b() private ? true
b() public ? false
moulon%

Guy Decoux