Generate feeds for each categorized entries

3 files changed, 63 insertions, 2 deletions

diff --git a/_plugins/generate-feeds-for-categories.rb b/_plugins/generate-feeds-for-categories.rb
new file mode 100644
index 0000000..f5cc8db
--- /dev/null
+++ b/_plugins/generate-feeds-for-categories.rb
@@ -0,0 +1,48 @@
+module Jekyll
+  class FeedsForCategoriesGenerator < Generator
+    safe true
+
+    def gen_categories_index(site)
+      categories_index = {}
+      site.collections.each do |collection|
+        collection_name, collection_documents = collection
+        collection_documents.docs.each do |document|
+          lang = document.data["lang"]
+          categories = document.data["eu_categories"]
+          if categories != nil
+            categories.split(",").each do |category|
+              categories_index[collection_name] ||= {}
+              categories_index[collection_name][lang] ||= {}
+              categories_index[collection_name][lang][category] ||= []
+
+              categories_index[collection_name][lang][category] << document
+            end
+          end
+        end
+      end
+      categories_index
+    end
+
+    def generate(site)
+      gen_categories_index(site).each do |collection_name, langs|
+        langs.each do |lang, categories|
+          categories.each do |category_name, articles|
+            category = category_name.gsub(/ /, '-')
+            feed_name = "feed.#{collection_name}-by-category.#{lang}.#{category}.atom"
+            page = PageWithoutAFile.new(site, site.source, "", feed_name)
+            page.content = <<-EOF
+{% include feed.atom entries=site.#{collection_name} kind="#{collection_name}" lang="#{lang}" categories_filter="#{category_name}" %}
+            EOF
+            site.pages << page
+          end
+        end
+      end
+    end
+  end
+
+  class PageWithoutAFile < Jekyll::Page
+    def read_yaml(*)
+      @data ||= {}
+    end
+  end
+end
diff --git a/_plugins/generate-pastebin-plaintext-alternate.rb b/_plugins/generate-pastebin-plaintext-alternate.rb
index 93cc74e..3b5fb9a 100644
--- a/_plugins/generate-pastebin-plaintext-alternate.rb
+++ b/_plugins/generate-pastebin-plaintext-alternate.rb
@@ -20,7 +20,7 @@ module Jekyll
                                       .gsub(/<span class=".*?">(.*?)<\/span>/m, '\1')
                 content = CGI.unescapeHTML unhighlighted_code
                 name = "#{document.url}.#{n}.txt"
-                plain = PageWithoutAFile.new(site, site.source, "", name)
+                plain = PlaintextPageWithoutAFile.new(site, site.source, "", name)
                 plain.content = content
                 site.pages << plain
                 n += 1
@@ -33,7 +33,7 @@ module Jekyll
 
   # Taken from:
   # https://github.com/jekyll/jekyll-feed/blob/c552b8ef7bd7a4babcfb5aec2b22283a5bc354dd/lib/jekyll-feed/page-without-a-file.rb#L4
-  class PageWithoutAFile < Jekyll::Page
+  class PlaintextPageWithoutAFile < Jekyll::Page
     def read_yaml(*)
       @data ||= {
         "plaintext" => "true"
diff --git a/_plugins/has-category-filter.rb b/_plugins/has-category-filter.rb
new file mode 100644
index 0000000..fee9b0d
--- /dev/null
+++ b/_plugins/has-category-filter.rb
@@ -0,0 +1,13 @@
+module Jekyll
+  module CategoryFilter
+    def has_category(input, category)
+      if category
+        input.select { |entry| entry.data["eu_categories"]&.split(',')&.include? category }
+      else
+        input
+      end
+    end
+  end
+end
+
+Liquid::Template.register_filter(Jekyll::CategoryFilter)