Extra conversion options

app/controllers/recipes_controller.rb

@@ -1,6 +1,6 @@
 class RecipesController < ApplicationController
 
-  before_action :set_recipe, only: [:show, :edit, :update, :destroy, :scale]
+  before_action :set_recipe, only: [:show, :edit, :update, :destroy]
 
   before_filter :ensure_valid_user, except: [:show, :scale, :index]
 
@@ -12,6 +12,31 @@ class RecipesController < ApplicationController
   # GET /recipes/1
   # GET /recipes/1.json
   def show
+    if params[:scale].present?
+      @scale = params[:scale]
+      @recipe.scale(params[:scale], true)
+    end
+
+    if params[:system].present?
+      @system = params[:system]
+      case @system
+        when 'metric'
+          @recipe.convert_to_metric
+        when 'standard'
+          @recipe.convert_to_standard
+      end
+    end
+
+    if params[:unit].present?
+      @unit = params[:unit]
+      case @unit
+        when 'mass'
+          @recipe.convert_to_mass
+        when 'volume'
+          @recipe.convert_to_volume
+      end
+    end
+
   end
 
   # GET /recipes/1

app/models/recipe.rb

@@ -30,6 +30,30 @@ class Recipe < ActiveRecord::Base
     end
   end
 
+  def convert_to_metric
+    recipe_ingredients.each do |ri|
+      ri.to_metric
+    end
+  end
+
+  def convert_to_standard
+    recipe_ingredients.each do |ri|
+      ri.to_standard
+    end
+  end
+
+  def convert_to_mass
+    recipe_ingredients.each do |ri|
+      ri.to_mass
+    end
+  end
+
+  def convert_to_volume
+    recipe_ingredients.each do |ri|
+      ri.to_volume
+    end
+  end
+
   def nutrition_data(recalculate = false)
     if recalculate || @nutrition_data.nil?
       @nutrition_data = calculate_nutrition_data

app/models/recipe_ingredient.rb

@@ -34,6 +34,52 @@ class RecipeIngredient < ActiveRecord::Base
     end
   end
 
+  def to_metric
+    return unless self.quantity.present?
+    value_unit = UnitConversion.parse(self.quantity, self.units)
+    value_unit = value_unit.to_metric
+
+    self.quantity = value_unit.pretty_value
+    self.units = value_unit.unit.to_s
+  end
+
+  def to_standard
+    return unless self.quantity.present?
+    value_unit = UnitConversion.parse(self.quantity, self.units)
+    value_unit = value_unit.to_standard
+
+    self.quantity = value_unit.pretty_value
+    self.units = value_unit.unit.to_s
+  end
+
+  def to_volume
+    return unless self.quantity.present?
+    if ingredient && ingredient.density
+      density = UnitConversion.parse(ingredient.density)
+      if density.density?
+        value_unit = UnitConversion.parse(self.quantity, self.units)
+        value_unit = value_unit.to_volume(density)
+
+        self.quantity = value_unit.pretty_value
+        self.units = value_unit.unit.to_s
+      end
+    end
+  end
+
+  def to_mass
+    return unless self.quantity.present?
+    if ingredient && ingredient.density
+      density = UnitConversion.parse(ingredient.density)
+      if density.density?
+        value_unit = UnitConversion.parse(self.quantity, self.units)
+        value_unit = value_unit.to_mass(density)
+
+        self.quantity = value_unit.pretty_value
+        self.units = value_unit.unit.to_s
+      end
+    end
+  end
+
   def can_convert_to_grams?
     if self.quantity.present? && self.units.present?
       value_unit = UnitConversion.parse(self.quantity, self.units)

app/views/recipes/show.html.erb

@@ -46,19 +46,9 @@
           <div class="row">
             <h3 class="panel-title col-xs-7">Ingredients</h3>
             <div class="dropdown col-xs-5">
-              <button id="scaleLabel" type="button" class="pull-right btn btn-xs btn-default" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
+              <button id="scaleLabel" type="button" class="pull-right btn btn-xs btn-default" data-toggle="modal" data-target="#translate_modal">
-                Scale
+                Translate
-                <span class="caret"></span>
               </button>
-              <ul class="dropdown-menu" aria-labelledby="scaleLabel">
-                <% ['1/4', '1/3', '1/2', '2/3', '3/4', '1', '1 1/2', '2', '3', '4'].each do |scale| %>
-                  <% if scale == '1' %>
-                    <li><%= link_to scale, @recipe %></li>
-                  <% else %>
-                    <li><%= link_to scale, scale_recipe_path(@recipe, scale) %></li>
-                  <% end %>
-                <% end %>
-              </ul>
             </div>
           </div>
 
@@ -152,4 +142,79 @@
     <%= link_to 'Back', recipes_path, class: 'btn btn-default' %>
 
   </div>
+</div>
+
+<div class="modal fade" id="translate_modal" tabindex="-1" role="dialog">
+  <div class="modal-dialog" role="document">
+    <div class="modal-content">
+      <div class="modal-header">
+        <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>
+        <h4 class="modal-title">Recipe Translation</h4>
+      </div>
+      <div class="modal-body">
+        <%= form_tag(recipe_path(@recipe), method: :get, authenticity_token: false, enforce_utf8: false, id: 'translate_form') do %>
+          <div class="row">
+            <div class="col-xs-12">
+
+              <div class="form-group form-group">
+                <%= label_tag :scale, 'Scale', class: "control-label" %>
+                <%= select_tag :scale, options_for_select(['1/4', '1/3', '1/2', '2/3', '3/4', '1', '1 1/2', '2', '3', '4'], '1'), class: 'form-control' %>
+              </div>
+
+              <div class="well">
+                <div class="radio">
+                  <label>
+                    <input type="radio" name="system" id="system_none" value="" checked>
+                    No System Translation
+                  </label>
+                </div>
+                <div class="radio">
+                  <label>
+                    <input type="radio" name="system" id="system_standard" value="standard">
+                    Convert to Standard Units
+                  </label>
+                </div>
+                <div class="radio">
+                  <label>
+                    <input type="radio" name="system" id="system_metric" value="metric">
+                    Convert to Metric Units
+                  </label>
+                </div>
+              </div>
+
+              <div class="well">
+                <div class="radio">
+                  <label>
+                    <input type="radio" name="unit" id="unit_none" value="" checked>
+                    No Unit Translation
+                  </label>
+                </div>
+                <div class="radio">
+                  <label>
+                    <input type="radio" name="unit" id="unit_mass" value="mass">
+                    Convert to Mass Units
+                  </label>
+                </div>
+                <div class="radio">
+                  <label>
+                    <input type="radio" name="unit" id="unit_volume" value="volume">
+                    Convert to Volume Units
+                  </label>
+                </div>
+              </div>
+
+            </div>
+          </div>
+        <% end %>
+      </div>
+
+
+      <div class="modal-footer">
+        <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
+        <button type="submit" class="btn btn-primary" form="translate_form">Convert</button>
+      </div>
+
+
+    </div>
+  </div>
 </div>

config/routes.rb

@@ -1,9 +1,7 @@
 Rails.application.routes.draw do
 
   resources :recipes do
-    member do
+
-      get 'scale/:factor', action: :scale, as: :scale
-    end
   end
 
   resources :ingredients, except: [:show] do

lib/unit_conversion/conversions.rb

@@ -80,4 +80,64 @@ module UnitConversion
     end
   end
 
+  class MetricUnitConversion < Conversion
+    def convert(value_unit)
+      if value_unit.unit && !value_unit.unit.metric?
+        if value_unit.mass?
+          value_unit = value_unit.convert('g').auto_unit
+        elsif value_unit.volume?
+          value_unit = value_unit.convert('ml').auto_unit
+        end
+      end
+
+      value_unit
+    end
+  end
+
+  class StandardUnitConversion < Conversion
+    def convert(value_unit)
+      if value_unit.unit && value_unit.unit.metric?
+        if value_unit.mass?
+          value_unit = value_unit.convert('oz').auto_unit
+        elsif value_unit.volume?
+          value_unit = value_unit.convert('cup').auto_unit
+        end
+      end
+
+      value_unit
+    end
+  end
+
+  class VolumeUnitConversion < Conversion
+    def initialize(density_unit_value)
+      raise UnknownUnitError, "#{density_unit_value} is not a density" if !density_unit_value.density?
+      @density = density_unit_value
+    end
+
+    def convert(value_unit)
+      if value_unit.mass?
+        unit = value_unit.unit.metric? ? 'ml' : 'cup'
+        value_unit.convert(unit, @density).auto_unit
+      else
+        value_unit
+      end
+    end
+  end
+
+  class MassUnitConversion < Conversion
+    def initialize(density_unit_value)
+      raise UnknownUnitError, "#{density_unit_value} is not a density" if !density_unit_value.density?
+      @density = density_unit_value
+    end
+
+    def convert(value_unit)
+      if value_unit.volume?
+        unit = value_unit.unit.metric? ? 'g' : 'oz'
+        value_unit.convert(unit, @density).auto_unit
+      else
+        value_unit
+      end
+    end
+  end
+
 end

lib/unit_conversion/value_unit.rb

@@ -4,6 +4,10 @@ module UnitConversion
     def self.for(value_string, unit_string = nil, formatter = nil)
       raise UnparseableUnitError, "value is empty" if value_string.blank?
 
+      if ValueUnit === value_string
+        return value_string
+      end
+
       if String === value_string && unit_string.nil?
         value_string, unit_string = parse_single_string(value_string)
       end
@@ -97,6 +101,24 @@ module UnitConversion
       AutoUnitConversion.new.convert(self)
     end
 
+    def to_metric
+      MetricUnitConversion.new.convert(self)
+    end
+
+    def to_standard
+      StandardUnitConversion.new.convert(self)
+    end
+
+    def to_mass(density)
+      parsed_density = ValueUnit.for(density)
+      MassUnitConversion.new(parsed_density).convert(self)
+    end
+
+    def to_volume(density)
+      parsed_density = ValueUnit.for(density)
+      VolumeUnitConversion.new(parsed_density).convert(self)
+    end
+
     def density?
       unit.density?
     end

spec/lib/unit_conversion/conversions_spec.rb

@@ -26,6 +26,16 @@ RSpec.describe UnitConversion::Conversion do
     end
   end
 
+  describe UnitConversion::MetricUnitConversion do
+    it 'converts standard units' do
+      expect(UnitConversion::MetricUnitConversion.new.convert(get_value_unit(1, 'cup')).unit.to_s).to eq 'milliliter'
+      expect(UnitConversion::MetricUnitConversion.new.convert(get_value_unit(1, 'cup')).pretty_value).to eq '236.588'
+
+      expect(UnitConversion::MetricUnitConversion.new.convert(get_value_unit(1, 'gallon')).unit.to_s).to eq 'liter'
+      expect(UnitConversion::MetricUnitConversion.new.convert(get_value_unit(1, 'gallon')).pretty_value).to eq '3.785'
+    end
+  end
+
   describe UnitConversion::ConvertConversion do
     it 'converts standard units' do
       expect(UnitConversion::ConvertConversion.new(get_unit('tbsp')).convert(get_value_unit(1, 'cups')).raw_value).to eq 16