Added Goal model and preliminary Targets index

app/models/goal.rb

@@ -0,0 +1,6 @@
+class Goal < ActiveRecord::Base
+  belongs_to :project, required: true
+  has_many :targets, inverse_of: :goal, dependent: :destroy
+
+  validates :name, presence: true, uniqueness: {scope: :project_id}
+end

app/models/ingredient.rb

@@ -2,7 +2,7 @@ class Ingredient < ActiveRecord::Base
   belongs_to :composition, inverse_of: :ingredients, polymorphic: true, required: true
   belongs_to :food, required: true
   belongs_to :part_of, required: false
-  has_many :nutrients, through: :food, source: :nutrients
+  has_many :nutrients, through: :food
 
   DOMAIN = :diet
   alias_attribute :subitems, :nutrients

app/models/nutrient.rb

@@ -1,6 +1,8 @@
 class Nutrient < QuantityValue
-  belongs_to :food, foreign_key: 'registry_id', foreign_type: 'registry_type',
-    inverse_of: :nutrients, polymorphic: true, required: true
+  # Need to specify polymorphic association so :registry_type gets written (see
+  # QuantityValue for explanation why it's needed)
+  belongs_to :food, inverse_of: :nutrients, polymorphic: true, required: true,
+    foreign_key: 'registry_id', foreign_type: 'registry_type'
 
   # Uniqueness NOT validated here, see Value for explanation
   #validates :quantity, uniqueness: {scope: :food_id}

app/models/quantity.rb

@@ -9,6 +9,7 @@ class Quantity < ActiveRecord::Base
   belongs_to :project, inverse_of: :quantities, required: false
   has_many :nutrients, dependent: :restrict_with_error
   has_many :readouts, dependent: :restrict_with_error
+  has_many :thresholds, dependent: :restrict_with_error
   has_many :values, class_name: 'QuantityValue', dependent: :restrict_with_error
   has_many :exposures, dependent: :destroy
 

app/models/quantity_value.rb

@@ -1,5 +1,9 @@
 class QuantityValue < ActiveRecord::Base
   # Requirement validation for :registry left to subclasses
+  # Polymorphic registry (including :registry_type) is required - despite 1:1
+  # mapping between Nutrient:Food, Readout:Measurement, Threshold:Target ... -
+  # to allow for accessing registry item without knowing QuantityValue (subitem)
+  # type, e.g. qv.registry.completed_at
   belongs_to :registry, polymorphic: true
   belongs_to :quantity, required: true
   belongs_to :unit, required: true

app/models/readout.rb

@@ -1,6 +1,8 @@
 class Readout < QuantityValue
-  belongs_to :measurement, foreign_key: 'registry_id', foreign_type: 'registry_type',
-    inverse_of: :readouts, polymorphic: true, required: true
+  # Need to specify polymorphic association so :registry_type gets written (see
+  # QuantityValue for explanation why it's needed)
+  belongs_to :measurement, inverse_of: :readouts, polymorphic: true, required: true,
+    foreign_key: 'registry_id', foreign_type: 'registry_type'
 
   # Uniqueness NOT validated here, see Value for explanation
   #validates :quantity, uniqueness: {scope: [:measurement_id, :unit_id]}

app/models/target.rb

@@ -10,5 +10,16 @@ class Target < ActiveRecord::Base
   # TODO: validate thresholds count according to condition type
   validates :condition, inclusion: {in: [:<, :<=, :>, :>=, :==]}
   validates :scope, inclusion: {in: [:day], if: -> { thresholds.first.domain == :diet }}
-  validates :effective_from, presence: {unless: goal?}, absence: {if: goal?}
+  validates :effective_from, presence: {unless: -> { goal.present? }},
+    absence: {if: -> { goal.present? }}
+
+  after_initialize do
+    if new_record?
+      self.condition = :<
+    end
+  end
+
+  def arity
+    BigDecimal.method(condition).arity
+  end
 end

app/models/threshold.rb

@@ -1,6 +1,8 @@
 class Threshold < QuantityValue
-  belongs_to :target, foreign_key: 'registry_id', foreign_type: 'foreign_type',
-    inverse_of: :thresholds, polymorphic: true, required: true
+  # Need to specify polymorphic association so :registry_type gets written (see
+  # QuantityValue for explanation why it's needed)
+  belongs_to :target, inverse_of: :thresholds, polymorphic: true, required: true,
+    foreign_key: 'registry_id', foreign_type: 'registry_type'
 
   validates :value, numericality: true
 end