Release 7.x backport 2970

app/components/blacklight/search_context/server_applied_params_component.html.erb

@@ -0,0 +1,4 @@
+<div id="appliedParams" class="clearfix constraints-container">
+  <%= render 'start_over' %>
+  <%= link_back_to_catalog class: 'btn btn-outline-secondary' %>
+</div>

app/components/blacklight/search_context/server_applied_params_component.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+module Blacklight
+  module SearchContext
+    class ServerAppliedParamsComponent < Blacklight::Component
+      delegate :current_search_session, :link_back_to_catalog, to: :helpers
+
+      def render?
+        current_search_session
+      end
+    end
+  end
+end

app/components/blacklight/search_context_component.rb

@@ -4,13 +4,14 @@ module Blacklight
   class SearchContextComponent < Blacklight::Component
     with_collection_parameter :search_context
 
-    def initialize(search_context:, search_session:)
+    def initialize(search_context:, search_session:, current_document: nil)
       @search_context = search_context
       @search_session = search_session
+      @current_document_id = current_document&.id
     end
 
     def render?
-      @search_context.present? && (@search_context[:prev] || @search_context[:next])
+      @search_context.present? && (@search_context[:prev] || @search_context[:next]) && (@current_document_id && @search_session['document_id'] == @current_document_id)
     end
 
     def item_page_entry_info

app/controllers/concerns/blacklight/search_context.rb

@@ -17,6 +17,28 @@ def record_search_parameters opts = { only: :index }
     end
   end
 
+  # GET previous and next document json for the document specified by
+  # the counter param in current search
+  def page_links
+    counter_param = params.delete(:counter)
+    @page_link_data = {}
+    if counter_param
+      index = counter_param.to_i - 1
+      response, documents = search_service.previous_and_next_documents_for_search index, search_state.reset_search
+      if documents.detect(&:present?)
+        @page_link_data[:prev] = page_links_document_path(documents.first, index)
+        @page_link_data[:next] = page_links_document_path(documents.last, index + 2)
+      end
+      if response&.total && response.total.positive?
+        @page_link_data[:counterRaw] = counter_param
+        @page_link_data[:counterDelimited] = helpers.number_with_delimiter(counter_param.to_i)
+        @page_link_data[:totalRaw] = response.total
+        @page_link_data[:totalDelimited] = helpers.number_with_delimiter(response.total)
+      end
+    end
+    render json: @page_link_data
+  end
+
   private
 
   # sets up the session[:search] hash if it doesn't already exist
@@ -79,6 +101,8 @@ def agent_is_crawler?
   end
 
   def find_or_initialize_search_session_from_params params
+    return unless blacklight_config.track_search_session_config.storage == 'server'
+
     params_copy = params.reject { |k, v| blacklisted_search_session_params.include?(k.to_sym) || v.blank? }
 
     return if params_copy.reject { |k, _v| [:action, :controller].include? k.to_sym }.blank?
@@ -109,15 +133,31 @@ def blacklisted_search_session_params
   # calls setup_previous_document then setup_next_document.
   # used in the show action for single view pagination.
   def setup_next_and_previous_documents
-    if search_session['counter'] && current_search_session
-      index = search_session['counter'].to_i - 1
-      response, documents = search_service.previous_and_next_documents_for_search index, search_state.reset(current_search_session.query_params)
+    return { counter: params[:counter] } if setup_next_and_previous_on_client?
+    return nil unless setup_next_and_previous_on_server?
 
-      search_session['total'] = response.total
-      { prev: documents.first, next: documents.last }
-    end
+    index = search_session['counter'].to_i - 1
+    response, documents = search_service.previous_and_next_documents_for_search index, search_state.reset(current_search_session.query_params)
+
+    search_session['total'] = response.total
+    { prev: documents.first, next: documents.last }
   rescue Blacklight::Exceptions::InvalidRequest => e
     logger&.warn "Unable to setup next and previous documents: #{e}"
     nil
   end
+
+  def setup_next_and_previous_on_server?
+    search_session['counter'] && current_search_session && blacklight_config.track_search_session_config.storage == 'server'
+  end
+
+  def setup_next_and_previous_on_client?
+    params[:counter] && blacklight_config.track_search_session_config.storage == 'client'
+  end
+
+  def page_links_document_path(document, counter)
+    return nil unless document
+    return search_state.url_for_document(document, counter: counter) if blacklight_config.view_config(:show).route
+
+    solr_document_path(document, counter: counter)
+  end
 end

app/helpers/blacklight/url_helper_behavior.rb

@@ -80,21 +80,24 @@ def link_to_next_document(next_document, classes: 'next', **addl_link_opts)
   # @example
   #   session_tracking_params(SolrDocument.new(id: 123), 7)
   #   => { data: { context_href: '/catalog/123/track?counter=7&search_id=999' } }
-  def session_tracking_params document, counter
-    path = session_tracking_path(document, per_page: params.fetch(:per_page, search_session['per_page']), counter: counter, search_id: current_search_session.try(:id), document_id: document&.id)
-
-    if path.nil?
-      return {}
+  def session_tracking_params document, counter, per_page: search_session['per_page'], search_id: current_search_session&.id
+    path_params = { per_page: params.fetch(:per_page, per_page), counter: counter, search_id: search_id }
+    if blacklight_config.track_search_session_config.storage == 'server'
+      path_params[:document_id] = document&.id
+      path_params[:search_id] = search_id
     end
+    path = session_tracking_path(document, path_params)
+    return {} if path.nil?
 
-    { data: { context_href: path, turbo_prefetch: false } }
+    context_method = blacklight_config.track_search_session_config.storage == 'client' ? 'get' : 'post'
+    { data: { context_href: path, context_method: context_method, turbo_prefetch: false } }
   end
   private :session_tracking_params
 
   ##
   # Get the URL for tracking search sessions across pages using polymorphic routing
   def session_tracking_path document, params = {}
-    return if document.nil? || !blacklight_config&.track_search_session
+    return if document.nil? || !blacklight_config.track_search_session_config.storage
 
     if main_app.respond_to?(controller_tracking_method)
       return main_app.public_send(controller_tracking_method, params.merge(id: document))
@@ -105,6 +108,8 @@ def session_tracking_path document, params = {}
   end
 
   def controller_tracking_method
+    return blacklight_config.track_search_session_config.url_helper if blacklight_config.track_search_session_config.url_helper
+
     "track_#{controller_name}_path"
   end
 

app/views/catalog/_show_main_content.html.erb

@@ -1,6 +1,6 @@
-<%= render(Blacklight::SearchContextComponent.new(search_context: @search_context, search_session: search_session)) if search_session['document_id'] == @document.id %>
+<%= render blacklight_config.track_search_session_config.item_pagination_component.new(search_context: @search_context, search_session: search_session, current_document: @document) if blacklight_config.track_search_session_config.item_pagination_component %>
 
-<% @page_title = t('blacklight.search.show.title', document_title: Deprecation.silence(Blacklight::BlacklightHelperBehavior) { document_show_html_title }, application_name: application_name).html_safe %>
+<% @page_title = t('blacklight.search.show.title', document_title: document_presenter(@document).html_title, application_name: application_name).html_safe %>
 <% content_for(:head) { render_link_rel_alternates } %>
 
 <%= render (blacklight_config.view_config(:show).document_component || Blacklight::DocumentComponent).new(presenter: document_presenter(@document), component: :div, title_component: :h1, show: true) do |component| %>

app/views/catalog/index.html.erb

@@ -1,3 +1,6 @@
+<% content_for(:head) do %>
+  <meta name="blacklight-search-storage" content="<%= blacklight_config.track_search_session_config.storage %>">
+<% end %>
 <% content_for(:sidebar) do %>
   <%= render 'search_sidebar' %>
 <% end %>

app/views/catalog/show.html.erb

@@ -1,9 +1,4 @@
-<% if current_search_session %>
-  <div id="appliedParams" class="clearfix constraints-container">
-    <%= render 'start_over' %>
-    <%= link_back_to_catalog class: 'btn btn-outline-secondary' %>
-  </div>
-<% end %>
+<%= render blacklight_config.track_search_session_config.applied_params_component.new if blacklight_config.track_search_session_config.applied_params_component %>
 
 <%= render 'show_main_content' %>
 

lib/blacklight/configuration.rb

@@ -306,6 +306,11 @@ def default_per_page
     # @return [Boolean]
     property :track_search_session, default: true
 
+    # @!attribute track_search_session_config
+    # @since v7.35.0
+    # @return [Blacklight::Configuration::SessionTrackingConfig]
+    property :track_search_session_config, default: nil
+
     # @!attribute advanced_search
     # @since v7.15.0
     # @return [#enabled]
@@ -618,6 +623,21 @@ def show_fields_for(document_or_display_types)
       fields.merge(show_fields)
     end
 
+    def track_search_session=(val)
+      self.track_search_session_config = Blacklight::Configuration::SessionTrackingConfig.new(storage: val ? 'server' : false)
+      super
+    end
+
+    def track_search_session_config
+      return track_search_session if track_search_session.is_a?(Blacklight::Configuration::SessionTrackingConfig)
+
+      stored_config = super
+
+      return stored_config if stored_config
+
+      self.track_search_session_config = Blacklight::Configuration::SessionTrackingConfig.new(storage: track_search_session ? 'server' : false)
+    end
+
     # @!visibility private
     def freeze
       each { |_k, v| v.is_a?(OpenStruct) && v.freeze }

lib/blacklight/configuration/session_tracking_config.rb

@@ -0,0 +1,45 @@
+# frozen_string_literal: true
+
+class Blacklight::Configuration
+  class SessionTrackingConfig < Blacklight::OpenStructWithHashAccess
+    # @!attribute storage
+    #   @return [String, FalseClass] 'server': use server-side tracking; 'client': delegate search tracking and prev/next navigation to client
+    # @!attribute applied_params_component
+    #   @return [Class] component class used to render a facet group
+    # @!attribute item_pagination_component
+    #   @return [Class] component class used to render the constraints
+
+    def initialize(property_hash = {})
+      super({ storage: 'server' }.merge(property_hash))
+    end
+
+    def applied_params_component
+      super || default_applied_params_component(storage)
+    end
+
+    def item_pagination_component
+      super || default_item_pagination_component(storage)
+    end
+
+    def url_helper
+      super || default_url_helper(storage)
+    end
+
+    def default_applied_params_component(storage)
+      return Blacklight::SearchContext::ServerAppliedParamsComponent if storage == 'server'
+
+      nil
+    end
+
+    def default_item_pagination_component(storage)
+      return Blacklight::SearchContextComponent if storage == 'server'
+
+      nil
+    end
+
+    # extension point for alternative storage types
+    def default_url_helper(_storage)
+      nil
+    end
+  end
+end

lib/blacklight/routes/searchable.rb

@@ -9,6 +9,7 @@ def initialize(defaults = {})
       def call(mapper, _options = {})
         mapper.match '/', action: 'index', as: 'search', via: [:get, :post]
         mapper.get '/advanced', action: 'advanced_search', as: 'advanced_search'
+        mapper.get '/page_links', action: 'page_links', as: 'page_links'
 
         mapper.post ":id/track", action: 'track', as: 'track'
         mapper.get ":id/raw", action: 'raw', as: 'raw', defaults: { format: 'json' }

spec/components/blacklight/document_component_spec.rb

@@ -26,7 +26,7 @@
 
   let(:blacklight_config) do
     CatalogController.blacklight_config.deep_copy.tap do |config|
-      config.track_search_session = false
+      config.track_search_session_config.storage = false
       config.index.thumbnail_field = 'thumbnail_path_ss'
       config.index.document_actions[:bookmark].partial = '/catalog/bookmark_control'
     end

spec/components/blacklight/search_context/server_applied_params_component_spec.rb

@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Blacklight::SearchContext::ServerAppliedParamsComponent, type: :component do
+  subject(:render) { instance.render_in(view_context) }
+
+  let(:instance) { described_class.new }
+  let(:current_search_session) { nil }
+  let(:view_context) { controller.view_context }
+
+  before do
+    view_context.view_paths.unshift(RSpec::Rails::ViewExampleGroup::StubResolverCache.resolver_for('application/_start_over.html.erb' => 'start over'))
+    allow(view_context).to receive(:current_search_session).and_return current_search_session
+    allow(view_context).to receive(:link_back_to_catalog).with(any_args)
+  end
+
+  it 'is blank without current session' do
+    expect(render).to be_blank
+  end
+
+  context 'with current session' do
+    let(:current_search_session) { double(query_params: { q: 'abc' }) }
+
+    it 'is not blank' do
+      expect(render).not_to be_blank
+    end
+  end
+end

spec/components/blacklight/search_context_component_spec.rb

@@ -0,0 +1,54 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Blacklight::SearchContextComponent, type: :component do
+  subject(:render) { render_inline(instance) }
+
+  let(:current_document_id) { 9 }
+  let(:current_document) { SolrDocument.new(id: current_document_id) }
+  let(:search_session) { { 'document_id' => current_document_id } }
+  let(:current_search_session) { double(id: current_document_id) }
+  let(:instance) { described_class.new(search_context: search_context, search_session: search_session, current_document: current_document) }
+
+  before do
+    allow(controller).to receive(:current_search_session).and_return(current_search_session)
+    allow(controller).to receive(:view_context).and_return(controller.view_context)
+    allow(controller.view_context).to receive(:current_search_session).and_return(current_search_session)
+    allow(controller.view_context).to receive(:search_session).and_return(search_session)
+  end
+
+  context 'when there is no next or previous' do
+    let(:search_context) { {} }
+
+    it "does not render content" do
+      expect(render.to_html).to be_blank
+    end
+  end
+
+  context 'when there is next and previous' do
+    let(:search_context) { { next: next_doc, prev: prev_doc } }
+    let(:prev_doc) { SolrDocument.new(id: '777') }
+    let(:next_doc) { SolrDocument.new(id: '888') }
+
+    before do
+      # allow(controller).to receive(:controller_tracking_method).and_return('track_catalog_path')
+      allow(controller).to receive(:controller_name).and_return('catalog')
+
+      allow(controller).to receive(:link_to_previous_document).and_return('')
+      allow(controller).to receive(:link_to_next_document).and_return('')
+    end
+
+    it "renders content" do
+      expect(render.css('.pagination-search-widgets').to_html).not_to be_blank
+    end
+
+    context "session and document are out of sync" do
+      let(:current_document) { SolrDocument.new(id: current_document_id + 1) }
+
+      it "does not render content" do
+        expect(render.to_html).to be_blank
+      end
+    end
+  end
+end

spec/controllers/bookmarks_controller_spec.rb

@@ -8,6 +8,7 @@
 
     it 'opts out of search session tracking' do
       expect(@controller.blacklight_config.track_search_session).to eq false
+      expect(@controller.blacklight_config.track_search_session_config.storage).to be false
     end
   end
 

spec/controllers/catalog_controller_spec.rb

@@ -919,6 +919,21 @@ def export_as_mock
       end
     end
   end
+
+  describe "page_links" do
+    it "has prev/next docs and result set data for non-empty result sets", integration: true do
+      get :page_links, params: { f: { "format" => 'Book' }, counter: 2 }
+      expect(assigns(:page_link_data)).not_to be_empty
+      expect(assigns(:page_link_data).fetch(:prev, nil)).to end_with('counter=1')
+      expect(assigns(:page_link_data).fetch(:next, nil)).to end_with('counter=3')
+      expect(assigns(:page_link_data).fetch(:totalRaw, nil)).to be 30
+    end
+
+    it "is empty for empty result sets", integration: true do
+      get :page_links, params: { f: { "format" => 'empty-result-set' }, counter: 1 }
+      expect(assigns(:page_link_data)).to be_empty
+    end
+  end
 end
 
 # there must be at least one facet, and each facet must have at least one value