add default_per_page configuration option, and add a #per_page_option…

…s_for_select helper to format the per page options for the template; fixes #818

app/helpers/blacklight/configuration_helper_behavior.rb

@@ -116,6 +116,14 @@ def default_sort_field
   ##
   # The default value for search results per page
   def default_per_page
-    blacklight_config.per_page.first unless blacklight_config.per_page.blank?
+    blacklight_config.default_per_page || blacklight_config.per_page.first
   end
-end
+
+  ##
+  # The available options for results per page, in the style of #options_for_select
+  def per_page_options_for_select
+    blacklight_config.per_page.map do |count|
+      [t(:'blacklight.search.per_page.label', :count => count).html_safe, count]
+    end
+  end
+end

app/views/catalog/_per_page_widget.html.erb

@@ -4,9 +4,9 @@
 <div id="per_page-dropdown" class="btn-group">
   <button type="button" class="btn btn-default dropdown-toggle" data-toggle="dropdown"><%= link_to(t(:'blacklight.search.per_page.button_label', :count => current_per_page), "#") %> <span class="caret"></span></button>
   <ul class="dropdown-menu">
-        <%- blacklight_config.per_page.each do |count| %>
-          <li><%= link_to(t(:'blacklight.search.per_page.label', :count => count).html_safe, url_for(params_for_search(:per_page => count))) %></li>
-        <%- end -%>
+    <%- per_page_options_for_select.each do |(label, count)| %>
+      <li><%= link_to(label, url_for(params_for_search(:per_page => count))) %></li>
+    <%- end -%>
   </ul>
 </div>
-<% end %>
+<% end %>

lib/blacklight/configuration.rb

@@ -70,6 +70,7 @@ def default_values
           :max_per_page => 100,
           # Options for the user for number of results to show per page
           :per_page => [10,20,50,100],
+          :default_per_page => nil,
           # how many searches to save in session history
           # (TODO: move the value into the configuration?)
           :search_history_window => Blacklight::Catalog::SearchHistoryWindow,

spec/helpers/configuration_helper_spec.rb

@@ -100,4 +100,25 @@
       label = helper.solr_field_label "default text", :key_a, :key_b
     end
   end
-end
+
+  describe "#default_per_page" do
+    it "should be the configured default per page" do
+      helper.stub(blacklight_config: double(default_per_page: 42))
+      expect(helper.default_per_page).to eq 42
+    end
+
+    it "should be the first per-page value if a default isn't set" do
+      helper.stub(blacklight_config: double(default_per_page: nil, per_page: [11, 22]))
+      expect(helper.default_per_page).to eq 11
+    end
+  end
+
+  describe "#per_page_options_for_select" do
+    it "should be the per-page values formatted as options_for_select" do
+      helper.stub(blacklight_config: double(per_page: [11, 22, 33]))
+      expect(helper.per_page_options_for_select).to include ["11<span class=\"sr-only\"> per page</span>", 11]
+      expect(helper.per_page_options_for_select).to include ["22<span class=\"sr-only\"> per page</span>", 22]
+      expect(helper.per_page_options_for_select).to include ["33<span class=\"sr-only\"> per page</span>", 33]
+    end
+  end
+end