Added the ability to define a max weight per package.

The max weight per package is useful if you want to

a) limit package weights so they don't go above carrier limits like UPS's 150lb limit.
b) have a company rule that splits boxes after a certain weight.

It is implemented to respect the countries max weight if that happens to be lower.

Signed-off-by: Nathan Lowrie <nate@finelineautomation.com>

Fixes #48

app/models/spree/calculator/active_shipping/base.rb

@@ -155,7 +155,7 @@ def retrieve_timings(origin, destination, packages)
         def convert_order_to_weights_array(order)
           multiplier = Spree::ActiveShipping::Config[:unit_multiplier]
           default_weight = Spree::ActiveShipping::Config[:default_weight]
-          max_weight = max_weight_for_country(order.ship_address.country)
+          max_weight = get_max_weight(order)
 
           weights = order.line_items.map do |line_item|
             item_weight = line_item.variant.weight.to_f
@@ -194,7 +194,7 @@ def packages(order)
           units = Spree::ActiveShipping::Config[:units].to_sym
           packages = []
           weights = convert_order_to_weights_array(order)
-          max_weight = max_weight_for_country(order.ship_address.country)
+          max_weight = get_max_weight(order)
 
           if max_weight <= 0
             packages << Package.new(weights.sum, [], :units => units)
@@ -214,6 +214,18 @@ def packages(order)
           packages
         end
 
+        def get_max_weight(order)
+          max_weight = max_weight_for_country(order.ship_address.country)
+          max_weight_per_package = Spree::ActiveShipping::Config[:max_weight_per_package] * Spree::ActiveShipping::Config[:unit_multiplier]
+          if max_weight == 0 and max_weight_per_package > 0
+            max_weight = max_weight_per_package
+          elsif max_weight > 0 and max_weight_per_package < max_weight and max_weight_per_package > 0
+            max_weight = max_weight_per_package
+          end
+
+          max_weight
+        end
+
         def cache_key(order)
           addr = order.ship_address
           line_items_hash = Digest::MD5.hexdigest(order.line_items.map {|li| li.variant_id.to_s + "_" + li.quantity.to_s }.join("|"))

app/views/spree/admin/active_shipping_settings/edit.html.erb

@@ -76,6 +76,10 @@
       <%= form.label(:handling_fee, "Handling Fee: ") + tag(:br) %>
       <%= preference_field_tag(:handling_fee,  @config[:handling_fee], :type => :integer) %>
     <% end %>
+    <%= form.field_container :max_weight_per_package do %>
+      <%= form.label(:max_weight_per_package, "Max Weight Per Package: ") + tag(:br) %>
+      <%= preference_field_tag(:max_weight_per_package,  @config[:max_weight_per_package], :type => :integer) %>
+    <% end %>
     <%= form.field_container :test_mode do %>
       <%= form.label(:test_mode, "Test Mode: ") + tag(:br) %>
       <%= preference_field_tag(:test_mode,  @config[:test_mode], :type => :boolean) %>

app/views/spree/admin/active_shipping_settings/show.html.erb

@@ -38,6 +38,10 @@
     <td>Handling Fee:</td>
     <td><%= @config[:handling_fee] %></td>
   </tr>
+  <tr>
+    <td>Max Weight Package:</td>
+    <td><%= @config[:max_weight_per_package] %></td>
+  </tr>
   <tr>
     <td>Test Mode:</td>
     <td><%= @config[:test_mode] %></td>

lib/spree/active_shipping_configuration.rb

@@ -23,6 +23,7 @@ class Spree::ActiveShippingConfiguration < Spree::Preferences::Configuration
   preference :unit_multiplier, :integer, :default => 16 # 16 oz./lb - assumes variant weights are in lbs
   preference :default_weight, :integer, :default => 0 # 16 oz./lb - assumes variant weights are in lbs
   preference :handling_fee, :integer
-
+  preference :max_weight_per_package, :integer, :default => 0 # 0 means no limit
+
   preference :test_mode, :boolean, :default => false
 end

spec/models/weight_limits_spec.rb

@@ -71,6 +71,17 @@ module ActiveShipping
         international_calculator.send(:max_weight_for_country, country).should == 66.0*Spree::ActiveShipping::Config[:unit_multiplier] # Canada
         domestic_calculator.send(:max_weight_for_country, country).should == 70.0*Spree::ActiveShipping::Config[:unit_multiplier]
       end
+
+      it "should respect the max weight per package" do
+        Spree::ActiveShipping::Config.set(:max_weight_per_package => 30)
+        weights = international_calculator.send :convert_order_to_weights_array, order
+        weights.should == [20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 21.0, 29.0].map{|x| x*Spree::ActiveShipping::Config[:unit_multiplier]}
+
+        packages = international_calculator.send :packages, order
+        packages.size.should == 12
+        packages.map{|package| package.weight.amount}.should == [20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 20.0, 21.0, 29.0].map{|x| x*Spree::ActiveShipping::Config[:unit_multiplier]}
+        packages.map{|package| package.weight.unit}.uniq.should == [:ounces]
+      end
     end
 
     describe "validation of line item weight" do