Info from Ruby file to Model?

Rails
1

Hi,

Newbie question…

If I have hundreds of methods I need a model to call
on depending on the situation (only one at a time), where should they
be kept, and how to
call them?

Thanks,
DC

2

On 13 March 2011 23:36, Dave C. [email protected] wrote:

I want a model to use info from a file (parks_bielkowski_test.rb)
residing in lib (standard ruby file containing a method called
“generated_question”, that returns a hash).

Can you make the file a module and mix it in?

3

On Mar 13, 11:36pm, Dave C. [email protected] wrote:

below) or, "undefined local variable or method `question_instance’ for

I dont seem to be able to get the model to see the hash created in the
“parks_bielkowski_test” file, and any suggestions would be helpful.

What does parks_bielkowski_test.rb look like? ( require ‘generators/
parks_bielkowski_test’ should be enough - your app’s lib folder
should be in ruby’s load path)

Fred

4

I will have hundreds of methods I need the model to call
on depending on the situation (only one at a time), where should they
be kept, and how to call them?

I have tried…

require “#{RAILS_ROOT}/lib/generators/parks_bielkowski_test.rb” in the
model to access the test file but it does not seem to return a value.
Is this the correct use of “require”?

The test file contains a module

DC

5

Thanks Fred, I am reading about inheritance and modules. I think using
the module is the correct way to do this but…

In model…

class Question < ActiveRecord::Base
require “#{RAILS_ROOT}/lib/generators/parks_bielkowski_test.rb”
include P_b

In parks_bielkowski_test.rb

module Parks_Bielkowski_test
def P_b
# Parks-Bielkowski step 1 result:
i = rand
if i < 0.5
ect…

I get the ERROR: uninitialized constant Question::P_b

Doesn’t seem to be including P_b

Thanks,
DC

6

On 15 Mar 2011, at 00:49, Dave C. [email protected] wrote:

I will have hundreds of methods I need the model to call
on depending on the situation (only one at a time), where should they
be kept, and how to call them?

I have tried…

require “#{RAILS_ROOT}/lib/generators/parks_bielkowski_test.rb” in the
model to access the test file but it does not seem to return a value.
Is this the correct use of “require”?

Require just loads the file. You don’t get a meaningful return value
from it

The test file contains a module

If you’ve defined your method in a module then in order to call that
method you need to include it in the current object (alternatively you
could make it a module method and then call SomeModule.method_name)

You might do well to do a little reading on how method lookup, modules,
inheritance etc work in ruby

Fred

7

On Mar 15, 12:12pm, Dave C. [email protected] wrote:

Thanks Fred, I am reading about inheritance and modules. I think using
the module is the correct way to do this but…

What you include is the module, not the methods in it

Fred

8

The book Metaprogramming in Ruby teaches everything you need to know
about modules and more. Also, you might the book Eloquent Ruby a very
nice introduction to Ruby and its finer points. It’s well-written and
dives into all facets (no pun intended) of Ruby.

9

Thank you.

DC

10

Frederick C. wrote in post #987535:

On Mar 15, 12:12pm, Dave C. [email protected] wrote:

Thanks Fred, I am reading about inheritance and modules. I think using
the module is the correct way to do this but…

What you include is the module, not the methods in it

Fred

Thanks Fred, Same error when I tried that:

uninitialized constant Question::Parks_Bielkowski_test

I’ll do some more research. I really appreciate your help and guidance
but obviously am missing something simple.

PS I am actually a non-programmer (physician) who is trying to write a
single program-finding this is a steep learning curve!!

Thanks,
DC

11

On Mar 15, 1:09pm, Dave C. [email protected] wrote:

Thanks Fred, Same error when I tried that:

uninitialized constant Question::Parks_Bielkowski_test

I’ll do some more research. I really appreciate your help and guidance
but obviously am missing something simple.

Have you still got the require there?

Fred