blogging.rb in nanoc-2.2

- old
+ new

@@ -19,26 +19,40 @@
   # To activate this helper, +include+ it, like this:
   #
   #   include Nanoc::Helpers::Blogging
   module Blogging
 
-    # Returns the list of articles, sorted by descending creation date (so
-    # newer articles appear first).
+    # Returns an unsorted list of articles.
+    def articles
+      @pages.select { |page| page.kind == 'article' }
+    end
+
+    # Returns a list of articles, sorted by descending creation date (so newer
+    # articles appear first).
     def sorted_articles
-      @pages.select do |page|
-        page.kind == 'article'
-      end.sort do |x,y|
-        y.created_at <=> x.created_at
-      end
+      articles.sort_by { |a| a.created_at }.reverse
     end
 
     # Returns a string representing the atom feed containing recent articles,
     # sorted by descending creation date. +params+ is a hash where the
     # following keys can be set:
     #
     # +limit+:: The maximum number of articles to show. Defaults to 5.
     #
+    # +articles+:: A list of articles to include in the feed. Defaults to the
+    #              list of articles returned by the articles function.
+    #
+    # +content_proc+:: A proc that returns the content of the given article,
+    #                  passed as a parameter. By default, given the argument
+    #                  +article+, this proc will return +article.content+.
+    #                  This function may not return nil.
+    #
+    # +excerpt_proc+:: A proc that returns the excerpt of the given article,
+    #                  passed as a parameter. By default, given the argument
+    #                  +article+, this proc will return +article.excerpt+.
+    #                  This function may return nil.
+    #
     # The following attributes must be set on blog articles:
     #
     # * 'title', containing the title of the blog post.
     #
     # * all other attributes mentioned above.
@@ -91,14 +105,42 @@
     #   <%= atom_feed %>
     def atom_feed(params={})
       require 'builder'
 
       # Extract parameters
-      limit = params[:limit] || 5
+      limit             = params[:limit] || 5
+      relevant_articles = params[:articles] || articles || []
+      content_proc      = params[:content_proc] || lambda { |a| a.content }
+      excerpt_proc      = params[:excerpt_proc] || lambda { |a| a.excerpt }
 
+      # Check feed page attributes
+      if @page.base_url.nil?
+        raise RuntimeError.new('Cannot build Atom feed: feed page has no base_url')
+      end
+      if @page.title.nil?
+        raise RuntimeError.new('Cannot build Atom feed: feed page has no title')
+      end
+      if @page.author_name.nil?
+        raise RuntimeError.new('Cannot build Atom feed: feed page has no author_name')
+      end
+      if @page.author_uri.nil?
+        raise RuntimeError.new('Cannot build Atom feed: feed page has no author_uri')
+      end
+
+      # Check article attributes
+      if relevant_articles.empty?
+        raise RuntimeError.new('Cannot build Atom feed: no articles')
+      end
+      if relevant_articles.any? { |a| a.created_at.nil? }
+        raise RuntimeError.new('Cannot build Atom feed: one or more articles lack created_at')
+      end
+
+      # Get sorted relevant articles
+      sorted_relevant_articles = relevant_articles.sort_by { |a| a.created_at }.reverse.first(limit)
+
       # Get most recent article
-      last_article = sorted_articles.first
+      last_article = sorted_relevant_articles.first
 
       # Create builder
       buffer = ''
       xml = Builder::XmlMarkup.new(:target => buffer, :indent => 2)
 
@@ -121,11 +163,11 @@
           xml.name  @page.author_name
           xml.uri   @page.author_uri
         end
 
         # Add articles
-        sorted_articles.first(limit).each do |a|
+        sorted_relevant_articles.each do |a|
           xml.entry do
             # Add primary attributes
             xml.id        atom_tag_for(a)
             xml.title     a.title, :type => 'html'
 
@@ -135,11 +177,12 @@
 
             # Add link
             xml.link(:rel => 'alternate', :href => url_for(a))
 
             # Add content
-            xml.content   a.content, :type => 'html'
-            xml.summary   a.excerpt, :type => 'html' unless a.excerpt.nil?
+            summary = excerpt_proc.call(a)
+            xml.content   content_proc.call(a), :type => 'html'
+            xml.summary   summary, :type => 'html' unless summary.nil?
           end
         end
       end
 
       buffer