Append duplicate views instead of overwriting them (except :default)

Author: jhollinger

lib/blueprinter/v2/dsl.rb

@@ -5,15 +5,15 @@ module V2
     # Methods for defining Blueprint fields and views
     module DSL
       #
-      # Define a new child view, which is a subclass of self.
+      # Define a new child view, which is a subclass of self. If a view with this name already exists, the definition will be appended.
       #
       # @param name [Symbol] Name of the view
-      # @param fields [Boolean] Inherit fields from parents
-      # @param options [Boolean] Inherit options from parents
-      # @param extensions [Boolean] Inherit extensions from parents
+      # @param fields [Boolean] Inherit fields from parents (default true)
+      # @param options [Boolean] Inherit options from parents (default true)
+      # @param extensions [Boolean] Inherit extensions from parents (default true)
       # @yield Define the view in the block
       #
-      def view(name, fields: true, options: true, extensions: true, &definition)
+      def view(name, fields: nil, options: nil, extensions: nil, &definition)
         raise Errors::InvalidBlueprint, "View name may not contain '.'" if name.to_s =~ /\./
 
         name = name.to_sym
@@ -22,7 +22,7 @@ def view(name, fields: true, options: true, extensions: true, &definition)
       end
 
       #
-      # Define a new partial.
+      # Define a new partial. If a partial with this name already exists, it will be replaced.
       #
       # @param name [Symbol] Name of the partial to create or import
       # @yield Define a new partial in the block

lib/blueprinter/v2/view_builder.rb

@@ -31,7 +31,8 @@ def []=(name, definition)
         name = name.to_sym
         raise Errors::InvalidBlueprint, "You may not redefine the default view" if name == :default
 
-        @pending[name] = definition
+        @pending[name] ||= []
+        @pending[name] << definition
       end
 
       #
@@ -46,14 +47,18 @@ def [](name)
           @mut.synchronize do
             next if @views.key?(name)
 
-            p = @pending[name]
+            defs = @pending[name]
+            inherit_fields = defs.reduce(true) { |acc, d| d.fields.nil? ? acc : d.fields }
+            inherit_options = defs.reduce(true) { |acc, d| d.options.nil? ? acc : d.options }
+            inherit_extensions = defs.reduce(true) { |acc, d| d.extensions.nil? ? acc : d.extensions }
+
             view = Class.new(@parent)
             view.views.reset
             view.append_name(name)
-            view.schema.clear unless p.fields
-            view.options.clear unless p.options
-            view.extensions.clear unless p.extensions
-            view.class_eval(&p.definition) if p.definition
+            view.schema.clear unless inherit_fields
+            view.options.clear unless inherit_options
+            view.extensions.clear unless inherit_extensions
+            defs.each { |d| view.class_eval(&d.definition) if d.definition }
             view.eval!(false)
             @views[name] = view
           end
@@ -66,6 +71,7 @@ def fetch(name)
         self[name] || raise(KeyError, "View '#{name}' not found")
       end
 
+      # Yield each name and view
       def each(&block)
         enum = Enumerator.new do |y|
           y.yield(:default, self[:default])
@@ -77,7 +83,9 @@ def each(&block)
       # Create a duplicate of this builder with a different default view
       def dup_for(blueprint)
         builder = self.class.new(blueprint)
-        @pending.each { |name, definition| builder[name] = definition }
+        @pending.each do |name, defs|
+          defs.each { |d| builder[name] = d }
+        end
         builder
       end
 

spec/v2/view_spec.rb

@@ -91,5 +91,15 @@
     it "can opt out of inheriting extensions" do
       expect(blueprint[:minimal].extensions).to eq([])
     end
+
+    it "can be extended" do
+      bp1 = Class.new(Blueprinter::V2::Base) do
+        view(:foo) { fields :id, :name }
+      end
+      bp2 = Class.new(bp1) do
+        view(:foo) { field :description }
+      end
+      expect(bp2.reflections[:foo].fields.keys.sort).to eq %i(description id name)
+    end
   end
 end