Move changeset XML generation to a view

app/views/changesets/_changeset.builder

@@ -0,0 +1,43 @@
+# basic attributes
+
+attrs = {
+  "id" => changeset.id,
+  "created_at" => changeset.created_at.xmlschema,
+  "open" => changeset.is_open?,
+  "comments_count" => changeset.comments.length,
+  "changes_count" => changeset.num_changes
+}
+attrs["closed_at"] = changeset.closed_at unless changeset.is_open?
+changeset.bbox.to_unscaled.add_bounds_to(attrs, "_") if changeset.bbox.complete?
+
+# user attributes
+
+if changeset.user.data_public?
+  attrs["uid"] = changeset.user_id
+  attrs["user"] = changeset.user.display_name
+end
+
+xml.changeset(attrs) do |changeset_xml_node|
+  changeset.tags.each do |k, v|
+    changeset_xml_node.tag(:k => k, :v => v)
+  end
+
+  # include discussion if requested
+
+  if @include_discussion
+    changeset_xml_node.discussion do |discussion_xml_node|
+      changeset.comments.includes(:author).each do |comment|
+        cattrs = {
+          "date" => comment.created_at.xmlschema
+        }
+        if comment.author.data_public?
+          cattrs["uid"] = comment.author.id
+          cattrs["user"] = comment.author.display_name
+        end
+        discussion_xml_node.comment(cattrs) do |comment_xml_node|
+          comment_xml_node.text(comment.body)
+        end
+      end
+    end
+  end
+end