From c63ae793313ce56c96599654b19109d09acb6e63 Mon Sep 17 00:00:00 2001
From: Benjamin Armintor <armintor@gmail.com>
Date: Tue, 3 Jan 2023 14:34:03 -0500
Subject: [PATCH] implement a configuration object for
 Blacklight::Configuration.track_search_session - allow configuration of
 components for applied parameters and item pagination - only build
 server-side search tracking data if using server-side tracking - extract
 applied_params html into a component

---
 .../server_applied_params_component.html.erb  |  4 ++
 .../server_applied_params_component.rb        | 13 ++++++
 .../concerns/blacklight/search_context.rb     | 30 ++++++++-----
 app/helpers/blacklight/url_helper_behavior.rb | 19 +++++---
 app/views/catalog/_show_main_content.html.erb |  4 +-
 app/views/catalog/index.html.erb              |  3 ++
 app/views/catalog/show.html.erb               |  7 +--
 lib/blacklight/configuration.rb               | 18 ++++++++
 .../configuration/session_tracking_config.rb  | 45 +++++++++++++++++++
 .../blacklight/document_component_spec.rb     |  2 +-
 .../server_applied_params_component_spec.rb   | 29 ++++++++++++
 spec/controllers/bookmarks_controller_spec.rb |  1 +
 .../session_tracking_config_spec.rb           | 37 +++++++++++++++
 13 files changed, 185 insertions(+), 27 deletions(-)
 create mode 100644 app/components/blacklight/search_context/server_applied_params_component.html.erb
 create mode 100644 app/components/blacklight/search_context/server_applied_params_component.rb
 create mode 100644 lib/blacklight/configuration/session_tracking_config.rb
 create mode 100644 spec/components/blacklight/search_context/server_applied_params_component_spec.rb
 create mode 100644 spec/lib/blacklight/configuration/session_tracking_config_spec.rb

diff --git a/app/components/blacklight/search_context/server_applied_params_component.html.erb b/app/components/blacklight/search_context/server_applied_params_component.html.erb
new file mode 100644
index 0000000000..7254cce572
--- /dev/null
+++ b/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>
diff --git a/app/components/blacklight/search_context/server_applied_params_component.rb b/app/components/blacklight/search_context/server_applied_params_component.rb
new file mode 100644
index 0000000000..d7783c714d
--- /dev/null
+++ b/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
diff --git a/app/controllers/concerns/blacklight/search_context.rb b/app/controllers/concerns/blacklight/search_context.rb
index fa3b0f5880..ccee37d6bf 100644
--- a/app/controllers/concerns/blacklight/search_context.rb
+++ b/app/controllers/concerns/blacklight/search_context.rb
@@ -101,6 +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?
@@ -131,25 +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
 
-    if blacklight_config.view_config(:show).route
-      search_state.url_for_document(document, counter: counter)
-    else
-      solr_document_path(document, counter: counter)
-    end
+    solr_document_path(document, counter: counter)
   end
 end
diff --git a/app/helpers/blacklight/url_helper_behavior.rb b/app/helpers/blacklight/url_helper_behavior.rb
index 16b5ddb0b0..bbcc9832ba 100644
--- a/app/helpers/blacklight/url_helper_behavior.rb
+++ b/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
 
diff --git a/app/views/catalog/_show_main_content.html.erb b/app/views/catalog/_show_main_content.html.erb
index cf9360c208..b50c6bfacd 100644
--- a/app/views/catalog/_show_main_content.html.erb
+++ b/app/views/catalog/_show_main_content.html.erb
@@ -1,6 +1,6 @@
-<%= render(Blacklight::SearchContextComponent.new(search_context: @search_context, search_session: search_session, current_document: @document)) %>
+<%= 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| %>
diff --git a/app/views/catalog/index.html.erb b/app/views/catalog/index.html.erb
index c0af2dbe12..5dd4f3bf61 100644
--- a/app/views/catalog/index.html.erb
+++ b/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 %>
diff --git a/app/views/catalog/show.html.erb b/app/views/catalog/show.html.erb
index 39533c8543..c09f46956b 100644
--- a/app/views/catalog/show.html.erb
+++ b/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' %>
 
diff --git a/lib/blacklight/configuration.rb b/lib/blacklight/configuration.rb
index 970913764d..65f9d9ac23 100644
--- a/lib/blacklight/configuration.rb
+++ b/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 +623,19 @@ 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 ? 'storage' : false)
+      super
+    end
+
+    def track_search_session_config
+      stored_config = super
+
+      return stored_config if stored_config
+
+      self.track_search_session_config = Blacklight::Configuration::SessionTrackingConfig.new(storage: track_search_session ? 'storage' : false)
+    end
+
     # @!visibility private
     def freeze
       each { |_k, v| v.is_a?(OpenStruct) && v.freeze }
diff --git a/lib/blacklight/configuration/session_tracking_config.rb b/lib/blacklight/configuration/session_tracking_config.rb
new file mode 100644
index 0000000000..b7d87f7ee1
--- /dev/null
+++ b/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
diff --git a/spec/components/blacklight/document_component_spec.rb b/spec/components/blacklight/document_component_spec.rb
index 74dada0616..12713882d0 100644
--- a/spec/components/blacklight/document_component_spec.rb
+++ b/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
diff --git a/spec/components/blacklight/search_context/server_applied_params_component_spec.rb b/spec/components/blacklight/search_context/server_applied_params_component_spec.rb
new file mode 100644
index 0000000000..ff21468e7f
--- /dev/null
+++ b/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
diff --git a/spec/controllers/bookmarks_controller_spec.rb b/spec/controllers/bookmarks_controller_spec.rb
index 05df6104ca..7e4bf8fdd4 100644
--- a/spec/controllers/bookmarks_controller_spec.rb
+++ b/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
 
diff --git a/spec/lib/blacklight/configuration/session_tracking_config_spec.rb b/spec/lib/blacklight/configuration/session_tracking_config_spec.rb
new file mode 100644
index 0000000000..ad0f648e9d
--- /dev/null
+++ b/spec/lib/blacklight/configuration/session_tracking_config_spec.rb
@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+RSpec.describe Blacklight::Configuration::SessionTrackingConfig do
+  subject(:config) { described_class.new }
+
+  it "defaults @storage to 'server'" do
+    expect(config.storage).to eq 'server'
+  end
+
+  context "@storage is set to 'server'" do
+    before do
+      config.storage = 'server'
+    end
+
+    it "defaults components values" do
+      expect(config.applied_params_component).to eq Blacklight::SearchContext::ServerAppliedParamsComponent
+    end
+
+    it "defaults tracking url helper" do
+      expect(config.url_helper).to be_nil
+    end
+  end
+
+  context "@storage is set to false" do
+    before do
+      config.storage = false
+    end
+
+    it "defaults components values" do
+      expect(config.applied_params_component).to be_nil
+    end
+
+    it "defaults tracking url helper" do
+      expect(config.url_helper).to be_nil
+    end
+  end
+end