Implementing date-based sorting for call numbers in the browse lists

.rubocop.yml

@@ -103,6 +103,7 @@ Metrics/LineLength:
     - 'lib/tasks/pulsearch.rake'
     - 'lib/tasks/server.rake'
     - '**/Gemfile'
+    - 'app/controllers/orangelight/browsables_controller.rb'
 
 Metrics/MethodLength:
   Exclude:

app/controllers/orangelight/browsables_controller.rb

@@ -87,6 +87,12 @@ def index
     @list_name = params[:model].name.demodulize.tableize.humanize
     @list_name = 'author-title headings' if @list_name == 'Name titles'
 
+    if @model == 'call_numbers'
+      @orangelight_browsables_sorted = Orangelight::CallNumber.sort_by_label_date(@orangelight_browsables.sort)
+    else
+      @orangelight_browsables_sorted = @orangelight_browsables.sort
+    end
+
     respond_to do |format|
       format.html # index.html.erb
       format.json { render json: @orangelight_browsables }

app/models/orangelight/call_number.rb

@@ -4,4 +4,45 @@ class Orangelight::CallNumber < ApplicationRecord
   def self.table_name_prefix
     'orangelight_'
   end
+
+  # Sorts an Array of CallNumber instances using their label dates
+  # @param [Array<Orangelight::CallNumber>] call_numbers
+  # @return [Array<Orangelight::CallNumber>] the (re)sorted Array
+  def self.sort_by_label_date(call_numbers)
+    sorted = []
+
+    call_numbers.each_slice(2) do |a, b|
+      if b.nil?
+        sorted << a
+      elsif a.label_date && b.label_date && ((a.label_date <=> b.label_date) == 1)
+        sorted << b
+        sorted << a
+      else
+        sorted << a
+        sorted << b
+      end
+    end
+
+    sorted
+  end
+
+  # Constructs a Date by parsing the label
+  # @return [Date]
+  def label_date
+    m = / (\d{4})(?!\d)/.match(label)
+    return unless m&.captures&.length == 1
+
+    values = m.captures
+    value = Date.parse("#{values.last}-01-01")
+    value
+  end
+
+  # Compares two CallNumber instances
+  # @see Object#<=>
+  # @param [Orangelight::CallNumber] other
+  # @return [Integer]
+  def <=>(other)
+    return 1 unless other.is_a?(self.class)
+    sort <=> other.sort
+  end
 end

app/views/orangelight/browsables/index.html.erb

@@ -33,7 +33,7 @@
 
   <% if @model != 'call_numbers' %>
     <ul class="browse">
-        <% @orangelight_browsables.each_with_index do |orangelight_name, i| %>
+        <% @orangelight_browsables_sorted.each_with_index do |orangelight_name, i| %>
 
           <% if orangelight_name.id == @match && @exact_match %>
             <li class="alert alert-info clickable-row" data-href="/catalog/?f[<%=@facet%>][]=<%=CGI.escape orangelight_name.label%>">
@@ -73,7 +73,7 @@
     </thead>
 
     <tbody >
-      <% @orangelight_browsables.each_with_index do |orangelight_name, i| %>
+      <% @orangelight_browsables_sorted.each_with_index do |orangelight_name, i| %>
         <% if orangelight_name.id == @match && @exact_match %>
           <tr class="alert alert-info clickable-row" data-href="/catalog/<%=orangelight_name.bibid%>">
             <strong>

spec/features/browsables_spec.rb

@@ -6,7 +6,7 @@
   describe 'Browse by Call Number' do
     it 'displays two browse entries before exact match' do
       visit '/browse/call_numbers?q=PL856.U673+A61213+2011&rpp=10'
-      expect(page.all('tr')[3][:class]).to eq('alert alert-info clickable-row')
+      expect(page.all('tr')[4][:class]).to eq('alert alert-info clickable-row')
     end
   end
 

spec/models/orangelight/call_number_spec.rb

@@ -0,0 +1,66 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe Orangelight::CallNumber do
+  subject(:call_number) { described_class.new(attributes) }
+
+  let(:attributes) do
+    {
+      label: 'Z342 .M48 1988'
+    }
+  end
+
+  describe '.sort_by_label_date' do
+    let(:call_number_2) { described_class.new(label: 'Z342 .M48 1990') }
+    let(:call_number_1) { described_class.new(label: 'Z342 .M48 1988') }
+    let(:call_numbers) do
+      [
+        call_number_2,
+        call_number_1
+      ]
+    end
+    let(:sorted_call_numbers) { described_class.sort_by_label_date(call_numbers) }
+
+    it 'sorts by label dates' do
+      expect(sorted_call_numbers).not_to be_empty
+      expect(sorted_call_numbers.length).to eq(2)
+      expect(sorted_call_numbers.first).to eq(call_number_1)
+      expect(sorted_call_numbers.last).to eq(call_number_2)
+    end
+  end
+
+  describe '#label_date' do
+    let(:label_date) { Date.parse('1988-01-01') }
+
+    it 'constructs a Date from the label attribute' do
+      expect(call_number.label_date).to eq(label_date)
+    end
+
+    context 'when the label does not contain a date' do
+      let(:attributes) do
+        {
+          label: 'Z342 .M48'
+        }
+      end
+
+      it 'does not construct a Date' do
+        expect(call_number.label_date).to be_nil
+      end
+    end
+  end
+
+  describe '#<=>' do
+    let(:attributes) do
+      {
+        sort: 'Z342 .M48 1988'
+      }
+    end
+    let(:call_number_2) { described_class.new(sort: 'Z342 .M48 1990') }
+
+    it 'compares two CallNumbers by the #sorted attribute' do
+      expect(call_number <=> call_number_2).to eq(-1)
+      expect(call_number_2 <=> call_number).to eq(1)
+    end
+  end
+end