datamapper / dm-is-list Goto Github PK

Greetings,

I have the following models, and I am using dm-is-list to sort them:

class Section
        include DataMapper::Resource

        property :id, Serial
        property :name, String, :length => 1..100
        property :credits, String, :length => 1..10

        has n, :courses, :through => Resource

        is :list, :scope => [:program_id]
    end

    class Course
        include DataMapper::Resource

        property :id, Serial
        property :subj, String, :length => 4
        property :code, String, :length => 3..5
        property :name, String, :length => 1..100
        property :description, Text
        property :credits, String, :length => 1..10

        has n, :sections, :through => Resource

    end

    class CourseSection
        include DataMapper::Resource

        belongs_to :course, :key => true
        belongs_to :section, :key => true

        is :list, :scope => [:section_id]
    end

I am unable to select a given course and move it, so I am moving the Course Sections. I can use CourseSection.move(position) without issue. My problem gets more complicated when I try to use move_to_list(sectionID, position).

dm-is-list is setting the position value to NULL (I have verified that position is being sent). I have even tried to use move_to_list(sectionID) with no position, and NULL is still saved to the database. Obviously, subsequent attempts to move the item after that fail.

I attempted to define the position property as not null but that just resulted in an error when it tried to save the null. Position should never be null. This is making the gem unusable for me at this time.

test case: https://github.com/FND/dm-is-list/compare/below_bug

the first .move :below fails - yet it succeeds if first doing an arbitrary .move :above

Since the RSpec test case seems potentially confusing, here's a sample script that might make it clearer:

module DEBUG

  def self.info
    puts Animal.all(:order => :position.asc).map(&:id).join("  ")
  end

  def self.move(id, vector, ref_id)
    puts Animal.get!(id).move vector => Animal.get!(ref_id)
  end

end

5.times do |i|
  name = "animal#{i}"
  Animal.create
end

DEBUG::info # 1  2  3  4  5
DEBUG::move 5, :below, 1 # false
DEBUG::info # 1  2  3  4  5
DEBUG::move 5, :above, 1 # true
DEBUG::info # 5  1  2  3  4
DEBUG::move 5, :below, 1 # true
DEBUG::info # 1  5  2  3  4

When I tried use dm-is-list with datamapper 1.3.0beta I error message with inherited hook.

Below I past part of necessary error message:

/.../gems/dm-core-f51603618654/lib/dm-core/support/hook.rb:169:in register_hook': inherited class method does not exist (ArgumentError) from /.../gems/dm-core-f51603618654/lib/dm-core/support/hook.rb:353:ininstall_hook'
from /.../gems/dm-core-f51603618654/lib/dm-core/support/hook.rb:72:in after_class_method' from /.../gems/1.9.1/bundler/gems/dm-is-list-6826cd2647bf/lib/dm-is-list/is/list.rb:297:inis_list'

Removing dm-is-list from model and application fixes this, but of course eliminates all dm-is-list functionality

See: datamapper/dm-sqlite-adapter#4

Since the position field will probably be constantly used for ordering, it might be nice to change the property definition to
property :position, Integer, :index => true

is it possible to have multiple TODO lists per user (for user/todo example)?