Add nanoc/ruledsl/filter.rb

Rules

@@ -7,6 +7,7 @@ require "nanoc-gzip"
 require "nanoc-webpack"
 require "nanoc-tidy"
 require_relative "nanoc/lib/require_rules"
+Nanoc::RuleDSL::CompilationRuleContext.prepend(Nanoc::RuleDSL::Filter)
 
 ##
 # Common vars
@@ -37,7 +38,7 @@ end
 # /sitemap.xml
 compile "/sitemap.xml.erb" do
   filter(:erb, locals: {locales:, name_by_id:})
-  filter(:strip)
+  filter Proc.new { _1.each_line.reject { |s| s.strip.empty? }.join }
   write("/sitemap.xml")
 end
 

nanoc.yaml

@@ -11,7 +11,7 @@ text_extensions: [
 prune:
   auto_prune: true
 
-lib_dirs: ['nanoc/lib']
+lib_dirs: ['nanoc/lib', 'nanoc/ruledsl']
 output_dir: build/al-quran/
 
 data_sources:

nanoc/lib/nanoc/filters/minify_json.rb

@@ -1,11 +0,0 @@
-# frozen_string_literal: true
-
-class Nanoc::Filters::MinifyJSON < Nanoc::Filter
-  require "json"
-  identifier :minify_json
-  type text: :text
-
-  def run(content, options = {})
-    JSON.dump(JSON.parse(content))
-  end
-end

nanoc/lib/nanoc/filters/strip.rb

@@ -1,10 +0,0 @@
-# frozen_string_literal: true
-
-class Nanoc::Filters::Strip < Nanoc::Filter
-  identifier :strip
-  type text: :text
-
-  def run(content, options = {})
-    content.each_line.reject { _1.strip.empty? }.join
-  end
-end

nanoc/ruledsl/filter.rb

@@ -0,0 +1,36 @@
+module Nanoc::RuleDSL
+  module Filter
+    ##
+    # @example
+    #   compile "/sitemap.xml.erb" do
+    #     filter(:erb)
+    #     filter Proc.new { _1.each_line.reject { |s| s.strip,empty? } }
+    #     write("/sitemap.xml")
+    #   end
+    #
+    # @param [Proc, Symbol] fn
+    #  The name of a Symbol, or Proc for an anonymous filter
+    #
+    # @param [Hash] options
+    #  Filter options
+    #
+    # @return [void]
+    def filter(fn, options = {})
+      if Proc === fn
+        id = random_id
+        Nanoc::Filter.define(id) { fn.call(_1, _2) }
+        super(id, options)
+      else
+        super(fn, options)
+      end
+    end
+
+    private
+
+    def random_id
+      name = item.identifier.to_s.gsub(%r|[./\\]|, "_")[/[A-Za-z0-9_]+/]
+      random = SecureRandom.alphanumeric
+      "__nanoc_#{name}_#{random}".to_sym
+    end
+  end
+end