first implementation of citeproc-ruby

cff.gemspec

@@ -48,6 +48,7 @@ Gem::Specification.new do |spec|
 
   spec.required_ruby_version = '>= 2.6'
 
+  spec.add_runtime_dependency 'citeproc-ruby', '~> 1.1', '>= 1.1.14'
   spec.add_runtime_dependency 'json_schema', '~> 0.21.0'
   spec.add_runtime_dependency 'language_list', '~> 1.2'
 

lib/array.rb

@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+# Copyright (c) 2018-2021 The Ruby Citation File Format Developers.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+##
+class Array
+
+  # Implementing the ActiveRecord method Array.wrap
+  # Wraps its argument in an array unless it is already an array (or array-like).
+  #
+  # Specifically:
+  #
+  # * If the argument is +nil+ an empty array is returned.
+  # * Otherwise, if the argument responds to +to_ary+ it is invoked, and its result returned.
+  # * Otherwise, returns an array with the argument as its single element.
+  #
+  #     Array.wrap(nil)       # => []
+  #     Array.wrap([1, 2, 3]) # => [1, 2, 3]
+  #     Array.wrap(0)         # => [0]
+
+  def self.wrap(object)
+    if object.nil?
+      []
+    elsif object.respond_to?(:to_ary)
+      object.to_ary || [object]
+    else
+      [object]
+    end
+  end
+end

lib/cff.rb

@@ -32,6 +32,7 @@ module CFF
   SCHEMA = JsonSchema.parse!(SCHEMA_FILE)                    # :nodoc:
 end
 
+require 'array'
 require 'cff/version'
 require 'cff/errors'
 require 'cff/util'
@@ -47,3 +48,6 @@ module CFF
 require 'cff/formatter/formatter'
 require 'cff/formatter/apa_formatter'
 require 'cff/formatter/bibtex_formatter'
+require 'cff/formatter/csl_formatter'
+require 'citeproc'
+require 'csl'

lib/cff/formatter/csl_formatter.rb

@@ -0,0 +1,94 @@
+# frozen_string_literal: true
+
+# Copyright (c) 2018-2021 The Ruby Citation File Format Developers.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+##
+module CFF
+  # initial set of preferred citation styles, based on the list used by
+  # Crossref and DataCite Search:
+
+  # apa
+  # chicago-fullnote-bibliography
+  # harvard-cite-them-right
+  # ieee
+  # university-of-york-mla
+  # vancouver
+
+  # Generates a formatted citation using citation style language (CSL)
+  # and the Ruby Citeproc processor
+  class CslFormatter < Formatter # :nodoc:
+
+    def self.format(model:, style: 'apa', locale: 'en-US') # rubocop:disable Metrics/MethodLength, Metrics/AbcSize
+      # only support built-in styles
+      return nil unless ['apa', 'harvard-cite-them-right', 'ieee'].include? style
+
+      return nil unless required_fields?(model)
+
+      CSL::Style.root = ::File.expand_path('../../../lib/styles', __dir__)
+      CSL::Locale.root = ::File.expand_path('../../../lib/locales', __dir__)
+
+      id = present?(model.doi) ? "https://doi.org/#{model.doi}" : nil
+
+      # citeproc_hsh is input format for citeproc-ruby
+      citeproc_hsh = {
+        # using type book is workaround for software for current CSL version
+        'type' => 'book',
+        'id' => present?(model.doi) ? "https://doi.org/#{model.doi}" : nil,
+        'categories' => Array.wrap(model.keywords),
+        'language' => 'eng', # Array.wrap(model.languages).first,
+        'author' => to_citeproc(model.authors),
+        'issued' => get_date_parts(model.date_released.to_s),
+        'abstract' => model.abstract,
+        #   'container-title' => container_title,
+        'DOI' => model.doi,
+        #   'publisher' => publisher,
+        'title' => model.title,
+        'URL' => present?(model.repository_code) ? model.repository_code : model.url,
+        # 'copyright' => model.copyright,
+        'version' => model.version
+      }.compact.symbolize_keys
+
+      cp = CiteProc::Processor.new style: style, locale: locale, format: 'html'
+      cp.import Array.wrap(citeproc_hsh)
+      bibliography = cp.render :bibliography, id: id
+      bibliography.first
+    end
+
+    # change authors into a format citeproc understands
+    def self.to_citeproc(element)
+      Array.wrap(element).map do |a|
+        {
+          'given' => a.fields['given-names'],
+          'non-dropping-particle' => a.fields['name-particle'],
+          'family' => a.fields['family-names'],
+          'suffix' => a.fields['name-suffix'],
+          'literal' => a.fields['name']
+        }.compact
+      end
+    end
+
+    # citeproc uses dates formatted as date parts
+    def self.get_date_parts(iso8601_time)
+      return { 'date-parts' => [[]] } unless present?(iso8601_time)
+
+      year = iso8601_time[0..3].to_i
+      month = iso8601_time[5..6].to_i
+      day = iso8601_time[8..9].to_i
+      { 'date-parts' => [[year, month, day].reject(&:zero?)] }
+    rescue TypeError, NoMethodError
+      nil
+    end
+  end
+end

lib/cff/model.rb

@@ -106,6 +106,30 @@ def to_apalike
       CFF::ApaFormatter.format(model: self)
     end
 
+    # :call-seq:
+    #   to_apa -> String
+    #
+    # Output this Model in APA format, using CSL.
+    def to_apa
+      CFF::CslFormatter.format(model: self, style: 'apa')
+    end
+
+    # :call-seq:
+    #   to_harvard -> String
+    #
+    # Output this Model in Harvard format, using CSL.
+    def to_harvard
+      CFF::CslFormatter.format(model: self, style: 'harvard-cite-them-right')
+    end
+
+    # :call-seq:
+    #   to_ieee -> String
+    #
+    # Output this Model in APA format, using CSL.
+    def to_ieee
+      CFF::CslFormatter.format(model: self, style: 'ieee')
+    end
+
     # :call-seq:
     #   to_bibtex -> String
     #