Dealing with multiple locales

Basically the idea is to just fetch the things in all the languages by
looping over the available locales.

The results are stored into fields like `en_items` or `es_item`, so we
can just fetch the right ones by checking the current locale.

There's a bit of a mess in the model itself because the
multi-languageness might happen at the single item level or at the
collection level, depending on which query has been used. The check
there is ugly, but restrucuring the collection to match the individual
items is even uglier.

The upshot is that we now pretty much get localized results for free in
bridgetown; we don't need to do anything beside setting up the available
locales like we'd have done anyway.

lib/dato_cms_graphql/graphql_base.rb

@@ -56,21 +56,33 @@ def parse(query)
       end
 
       def query_for
-        parse <<~GRAPHQL
-          query($skip: IntType) {
-            items: all#{plural_name}(first: #{graphql_page_size}, skip: $skip) {
+        localized_items = I18n.available_locales.map do |locale|
+          <<~GRAPHQL
+            #{locale}_items: all#{plural_name}(locale: #{locale}, first: #{graphql_page_size}, skip: $skip) {
               #{fields}
             }
+          GRAPHQL
+        end
+
+        parse <<~GRAPHQL
+          query($skip: IntType) {
+            #{localized_items.join("\n")} 
           }
         GRAPHQL
       end
 
       def query_for_single
-        parse <<~GRAPHQL
-          query {
-            item: #{single_name} {
+        localized_item = I18n.available_locales.map do |locale|
+          <<~GRAPHQL
+            #{locale}_item: #{single_name}(locale: #{locale}) {
               #{fields}
             }
+          GRAPHQL
+        end
+
+        parse <<~GRAPHQL
+          query {
+            #{localized_item.join("\n")} 
           }
         GRAPHQL
       end
@@ -109,16 +121,24 @@ def render?
     render(true)
 
     def initialize(attributes)
-      @attributes = JSON.parse(attributes.to_json, object_class: OpenStruct)
+      @attributes = attributes
+    end
+
+    def localized_attributes
+      if @attributes.respond_to?(:"#{I18n.locale}_item")
+        @attributes.send(:"#{I18n.locale}_item")
+      else
+        @attributes
+      end
     end
 
     def respond_to_missing?(method, *args)
-      @attributes.respond_to?(method)
+      localized_attributes.respond_to?(method)
     end
 
     def method_missing(method, *a, &block)
-      if @attributes.respond_to?(method)
-        @attributes.send(method, *a, &block)
+      if localized_attributes.respond_to?(method)
+        localized_attributes.send(method, *a, &block)
       else
         super
       end

lib/dato_cms_graphql/model_iterator.rb

@@ -15,7 +15,7 @@ def each
       0.upto(@pages) do |page|
         @results = DatoCmsGraphql.query(@query, variables: {skip: @page_size * page})
 
-        @results.each do |element|
+        @results.send(:"#{I18n.locale}_items").each do |element|
           yield @model.new(element)
         end
       end