base.rb in pragma-operation-1.2.0

- old
+ new

@@ -75,10 +75,11 @@
         def inherited(child)
           child.class_eval do
             before :setup_context
             around :handle_halt
             after :mark_result, :consolidate_status, :validate_status, :set_default_status
+            after :build_links
           end
         end
 
         # Returns the name of this operation.
         #
@@ -119,23 +120,25 @@
       #
       # Note that calling this method doesn't halt the execution of the operation and that this
       # method can be called multiple times, overriding the previous context.
       #
       # @param status [Integer|Symbol] an HTTP status code
-      # @param headers [Hash] HTTP headers
       # @param resource [Object] an object responding to +#to_json+
-      def respond_with(status: nil, headers: {}, resource: nil)
-        context.status = status
-        context.headers = headers.to_h
-        context.resource = resource
+      # @param headers [Hash] HTTP headers
+      # @param links [Hash] links to use for building the +Link+ header
+      def respond_with(status: nil, resource: nil, headers: nil, links: nil)
+        context.status = status if status
+        context.resource = resource if resource
+        context.headers = headers if headers
+        context.links = links if links
       end
 
       # Same as {#respond_with}, but also halts the execution of the operation.
       #
       # @see #respond_with
       def respond_with!(*args)
-        respond_with *args
+        respond_with(*args)
         fail Halt
       end
 
       # Sets the status to respond with.
       #
@@ -166,10 +169,28 @@
       # @return [Object]
       def current_user
         context.current_user
       end
 
+      # Returns the headers we are responding with.
+      #
+      # This is just a shortcut for +context.headers+.
+      #
+      # @return [Hash]
+      def headers
+        context.headers
+      end
+
+      # Returns the links we are responding with.
+      #
+      # This is just a shotcut for +context.links+.
+      #
+      # @return [Hash]
+      def links
+        context.links
+      end
+
       private
 
       def with_hooks
         # This overrides the default behavior, which is not to run after hooks if an exception is
         # raised either in +#call+ or one of the before hooks. See:
@@ -185,10 +206,11 @@
       end
 
       def setup_context
         context.params ||= {}
         context.headers = {}
+        context.links = {}
       end
 
       def handle_halt(interactor)
         interactor.call
       rescue Halt # rubocop:disable Lint/HandleExceptions
@@ -216,9 +238,21 @@
       end
 
       def mark_result
         return if /\A(2|3)\d{2}\z/ =~ STATUSES.invert[context.status].to_s
         context.fail!
+      end
+
+      def build_links
+        headers.delete('Link')
+
+        link_header = context.links.each_pair.select do |relation, url|
+          url && !url.empty?
+        end.map do |relation, url|
+          %(<#{url}>; rel="#{relation}")
+        end.join(",\n  ")
+
+        headers['Link'] = link_header unless link_header.empty?
       end
     end
 
     Halt = Class.new(StandardError)
 