Support namespace addons

spec/cryss_spec.cr

@@ -15,26 +15,6 @@
 require "./spec_helper"
 
 describe RSS do
-  ex_cloud = RSS::Cloud.new(
-    domain: "rpc.sys.com",
-    port: 80,
-    path: "/RPC2",
-    register_procedure: "pingMe",
-    protocol: "soap"
-  )
-
-  ex_enclosure = RSS::Enclosure.new(
-    url: "http://live.curry.com/mp3/celebritySCms.mp3",
-    length: 1069871,
-    type: "audio/mpeg"
-  )
-
-  base_channel = RSS::Channel.new(
-    link: "http://www.goupstate.com/",
-    title: "GoUpstate.com News Headlines",
-    description: "The latest news from GoUpstate.com, a Spartanburg Herald-Journal Web site."
-  )
-
   it "builds enclosure" do
     w3 = HEADER + ENCLOSURE_TEST
 
@@ -85,5 +65,23 @@ describe RSS do
     chan = base_channel
     chan.skip_days = [RSS::Day::Monday, RSS::Day::Wednesday]
     chan.skip_hours = [2, 6, 18, 22]
+
+    chan.to_s.strip.should eq SKIP_DAY_TEST
+  end
+
+  it "adds namespace" do
+    chan = base_channel
+    chan.add_ns(dc: "http://purl.org/dc/elements/1.1")
+    chan.ns("dc") do |dc|
+      dc["rights"] = "Copyright 2002"
+    end
+
+    item = RSS::Item.new(title: "New item")
+    item.ns("dc") do |dc|
+      dc["subject"] = "CSS"
+    end
+    chan << item
+
+    chan.to_s.strip.should eq NAMESPACE_TEST
   end
 end

spec/spec_helper.cr

@@ -15,6 +15,32 @@
 require "spec"
 require "../src/cryss"
 
+def ex_cloud
+  RSS::Cloud.new(
+    domain: "rpc.sys.com",
+    port: 80,
+    path: "/RPC2",
+    register_procedure: "pingMe",
+    protocol: "soap"
+  )
+end
+
+def ex_enclosure
+  RSS::Enclosure.new(
+    url: "http://live.curry.com/mp3/celebritySCms.mp3",
+    length: 1069871,
+    type: "audio/mpeg"
+  )
+end
+
+def base_channel
+  RSS::Channel.new(
+    link: "http://www.goupstate.com/",
+    title: "GoUpstate.com News Headlines",
+    description: "The latest news from GoUpstate.com, a Spartanburg Herald-Journal Web site."
+  )
+end
+
 HEADER = "<?xml version=\"1.0\"?>\n"
 
 CLOUD_TEST = "<cloud domain=\"rpc.sys.com\" port=\"80\" path=\"/RPC2\" registerProcedure=\"pingMe\" protocol=\"soap\"/>"
@@ -63,6 +89,8 @@ SKIP_DAY_TEST = HEADER + <<-XML
     <title>GoUpstate.com News Headlines</title>
     <link>http://www.goupstate.com/</link>
     <description>The latest news from GoUpstate.com, a Spartanburg Herald-Journal Web site.</description>
+    <docs>https://validator.w3.org/feed/docs/rss2.html</docs>
+    <generator>cryss</generator>
     <skipHours>
       <hour>2</hour>
       <hour>6</hour>
@@ -76,3 +104,20 @@ SKIP_DAY_TEST = HEADER + <<-XML
   </channel>
 </rss>
 XML
+
+NAMESPACE_TEST = HEADER + <<-XML
+<rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1">
+  <channel>
+    <title>GoUpstate.com News Headlines</title>
+    <link>http://www.goupstate.com/</link>
+    <description>The latest news from GoUpstate.com, a Spartanburg Herald-Journal Web site.</description>
+    <docs>https://validator.w3.org/feed/docs/rss2.html</docs>
+    <generator>cryss</generator>
+    <dc:rights>Copyright 2002</dc:rights>
+    <item>
+      <title>New item</title>
+      <dc:subject>CSS</dc:subject>
+    </item>
+  </channel>
+</rss>
+XML

src/cryss/channel.cr

@@ -137,6 +137,8 @@ module RSS
     # Contained elements of the channel.
     getter items : Array(Item) = [] of Item
 
+    @namespaces = {} of String => String
+
     def initialize(link : URI | String, @title : String, @description : String)
       @link = link.is_a?(URI) ? link : URI.parse link
     end
@@ -149,9 +151,21 @@ module RSS
       push item
     end
 
+    def add_ns(name : String | Symbol,
+               url : URI | String)
+      @namespaces["xmlns:#{name.to_s}"] = url.to_s
+    end
+
+    def add_ns(**ns)
+      ns.each do |k, v|
+        add_ns(k, v)
+      end
+    end
+
     # Serialises the channel to the XML builder.
     def to_xml(xml : XML::Builder)
       xml.element("rss", version: "2.0") do
+        xml.attributes(@namespaces)
         xml.element("channel") do
           emit title
           emit link
@@ -197,6 +211,8 @@ module RSS
             end
           end
 
+          emit_custom xml
+
           @items.each do |item|
             item.to_xml xml
           end

src/cryss/element.cr

@@ -16,6 +16,8 @@ require "xml"
 
 module RSS
   abstract class Element
+    @custom = {} of String => Hash(String, String)
+
     def to_s(io : IO)
       to_xml(io)
     end
@@ -27,6 +29,38 @@ module RSS
       end
     end
 
+    # Adds a non-standard namespaced element to the component.
+    #
+    # Yields access to a set of namespaced elements and their values.
+    #
+    # Examples taken from [here](http://static.userland.com/gems/backend/rssMarkPilgrimExample.xml).
+    #
+    # ```crystal
+    # channel = RSS::Channel.new(/* ... */)
+    # channel.add_ns(dc: "http://purl.org/dc/elements/1.1")
+    # channel.ns("dc") do |dc|
+    #   dc["rights"] = "Copyright 2002"
+    # end
+    #
+    # item = RSS::Item.new(title: "New item")
+    # item.ns("dc") do |dc|
+    #   dc["subject"] = "CSS"
+    # end
+    #
+    # channel << item
+    # ```
+    #
+    # If the namespace already exists, it will yield access to the already existing namespace rather
+    # than overwriting it. Duplicate keys inside that namespace will overwrite, however.
+    #
+    # Note that no sanity checking is (currently) done before serializing an element with a custom
+    # namespaced element, as only the top-level element (a `Channel`) has access to specifying the
+    # namespace imports.
+    def ns(name : String, &block)
+      @custom[name] = {} of String => String if @custom[name]?.nil?
+      yield @custom[name]
+    end
+
     # Writes the generated XML to the provided *xml* builder.
     abstract def to_xml(xml : XML::Builder)
 
@@ -37,5 +71,13 @@ module RSS
     private macro emit(elem, name)
       xml.element({{name}}) { xml.text @{{elem}}.to_s }
     end
+
+    private def emit_custom(xml)
+      @custom.each do |ns, content|
+        content.each do |key, val|
+          xml.element("#{ns}:#{key}") { xml.text val }
+        end
+      end
+    end
   end
 end

src/cryss/image.cr

@@ -71,6 +71,8 @@ module RSS
         emit width if @width
         emit height if @height
         emit description if @description
+
+        emit_custom xml
       end
     end
   end

src/cryss/item.cr

@@ -135,6 +135,8 @@ module RSS
           xml.element("pubDate") { xml.text pub.to_rfc2822 }
         end
         xml.element("source", url: @source_url.to_s) { xml.text @source.to_s } if @source
+
+        emit_custom xml
       end
     end
   end