1 files changed, 95 insertions, 0 deletions
diff --git a/lib/public_body_csv.rb b/lib/public_body_csv.rb
new file mode 100644
index 000000000..afb5d9043
--- /dev/null
+++ b/lib/public_body_csv.rb
@@ -0,0 +1,95 @@
+require 'csv'
+
+# Public: Generate a CSV representation of PublicBody instances
+#
+# Examples
+#
+#   bodies = PublicBody.search('useless')
+#
+#   csv = PublicBodyCSV.new(:fields => [:name, :calculated_home_page],
+#                           :headers => ['Name', 'Home Page'])
+#
+#   bodies.each { |body| csv << body }
+#
+#   csv.generate
+#   # => Name,Home Page
+#        Department for Humpadinking,http://localhost
+#        Ministry of Silly Walks,http://www.localhost
+#        Department of Loneliness,http://localhost
+class PublicBodyCSV
+
+    def self.default_fields
+        [:name,
+         :short_name,
+         :url_name,
+         :tag_string,
+         :calculated_home_page,
+         :publication_scheme,
+         :disclosure_log,
+         :notes,
+         :created_at,
+         :updated_at,
+         :version]
+    end
+
+    # TODO: Generate headers from fields
+    def self.default_headers
+        ['Name',
+         'Short name',
+         'URL name',
+         'Tags',
+         'Home page',
+         'Publication scheme',
+         'Disclosure log',
+         'Notes',
+         'Created at',
+         'Updated at',
+         'Version']
+    end
+
+    attr_reader :fields, :headers, :rows
+
+    def initialize(args = {})
+        @fields = args.fetch(:fields, self.class.default_fields)
+        @headers = args.fetch(:headers, self.class.default_headers)
+        @rows = []
+    end
+
+    def <<(public_body)
+        # Allow join_rows to handle newlines because of differences between
+        # CSV.generate_line in 1.8 / 1.9+
+        if RUBY_VERSION.to_f >= 1.9
+            rows << CSV.generate_line(collect_public_body_attributes(public_body), :row_sep => '')
+        else
+            rows << CSV.generate_line(collect_public_body_attributes(public_body))
+        end
+    end
+
+    # TODO: Just use CSV.generate when Ruby 1.8.7 support is dropped
+    def generate
+        csv = generate_header_row
+        csv << join_rows
+        csv << "\n"
+    end
+
+    private
+
+    def join_rows
+        rows.join("\n")
+    end
+
+    def generate_header_row
+        # Add a newline because of differences between
+        # CSV.generate_line in 1.8 / 1.9+
+        row = CSV.generate_line(headers)
+        row += "\n" unless RUBY_VERSION.to_f >= 1.9
+        row
+    end
+
+    def collect_public_body_attributes(public_body)
+        fields.map do |field|
+            public_body.respond_to?(field) ? public_body.send(field) : ''
+        end
+    end
+
+end