Problem with a selfmade helper method

Rails
1

Hi all,

i tried to set up the helper method “grouped_programs_selector” in
application_helpers.rb. Since i dont have a deep understanding of Ruby
itself, I pretty much copied the Grouped Selection List (Chapter 17, pp.
259, 260) example from Dave & David’s Book.
The optiongroups are properly created by my method, but there are no
options
inside. Maybe you can debug this one?

-snip- from index.rhtml

<%=
option_groups_from_collection_for_select(
grouped_programs_selector(:programs, :programtypes), # calling
application_helper - method.
:options, :type_name,
:id, :name,
@programs)
%>

-snap- application_helper.rb

module ApplicationHelper

class ProgramOption
    attr_reader :attributes
    @attributes = []
    def initialize(id, name)
        @attributes = Struct.new(@id, @name)
    end
end

class ProgramType
    attr_reader :type_name, :options
    def initialize(name)
        @type_name=name
        @options=[]
    end
    def <<(option)
        @options << option
    end
end

The actual helper method

def grouped_programs_selector(programs, programtypes)
    groups = []
    @programtypes.each do |pt|
        newgroup = ProgramType.new(pt.name)
        @programs.each do |pr|
            if pt.id == pr.programtype
                newgroup << ProgramOption.new(pr.id, pr.name)
            end
        end
        groups << newgroup
    end
    return groups
end

end

2

In your ProgramOption’s constructor, I think you have to use id and name
instead of @id and @name

3

Thanks for your quick answer.
Nope, that didn’t do the trick. But I found, that

if pt.id == pr.programtype

is never getting true. Strange…

4

Timo wrote:

Thanks for your quick answer.
Nope, that didn’t do the trick. But I found, that

if pt.id http://pt.id/ == pr.programtype

is never getting true. Strange…
That’s because you’re comparing a Fixnum to a ProgramType. Try:
if pt == pr.programtype