🎁 Add ability to pass search term to PDF.js

This commit will add a PDF's text to the file set's solr document so it
can be searched in the catalog.  Now we can pass the search term to the
viewer so when it loads it will highlight the search term.

app/helpers/pdf_js_helper.rb

@@ -2,7 +2,7 @@
 
 module PdfJsHelper
   def pdf_js_url(path)
-    "/pdf.js/web/viewer.html?file=#{path}"
+    "/pdf.js/web/viewer.html?file=#{path}##{query_param}"
   end
 
   def pdf_file_set_presenter(presenter)
@@ -13,4 +13,10 @@ def pdf_file_set_presenter(presenter)
   def representative_presenter(presenter)
     presenter.file_set_presenters.find { |file_set_presenter| file_set_presenter.id == presenter.representative_id }
   end
+
+  def query_param
+    return unless params[:q]
+
+    "search=#{params[:q]}&phrase=true"
+  end
 end

app/helpers/shared_search_helper.rb

@@ -17,7 +17,10 @@ def generate_work_url(model, request)
       id = model["id"]
     end
     request_params = %i[protocol host port].map { |method| ["request_#{method}".to_sym, request.send(method)] }.to_h
-    get_url(id: id, request: request_params, account_cname: account_cname, has_model: has_model)
+    url = get_url(id: id, request: request_params, account_cname: account_cname, has_model: has_model)
+
+    # pass search query params to work show page
+    params[:q].present? ? "#{url}?q=#{params[:q]}" : url
   end
 
   private

app/indexers/hyrax/file_set_indexer_decorator.rb

@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+# OVERRIDE Hyrax 3.5.0 to add PDF text to solr document when using the default PDF viewer (PDF.js)
+
+module Hyrax
+  module FileSetIndexerDecorator
+    def generate_solr_document
+      return super unless Flipflop.default_pdf_viewer?
+
+      super.tap do |solr_doc|
+        solr_doc['all_text_timv'] = solr_doc['all_text_tsimv'] = pdf_text
+      end
+    end
+
+    private
+
+      def pdf_text
+        return unless object.pdf?
+        return unless object.original_file&.content.is_a? String
+
+        text = IO.popen(['pdftotext', '-', '-'], 'r+b') do |pdftotext|
+          pdftotext.write(object.original_file.content)
+          pdftotext.close_write
+          pdftotext.read
+        end
+
+        text.tr("\n", ' ')
+            .squeeze(' ')
+            .encode('UTF-8', 'binary', invalid: :replace, undef: :replace, replace: '') # remove non-UTF-8 characters
+      end
+  end
+end
+
+Hyrax::FileSetIndexer.prepend(Hyrax::FileSetIndexerDecorator)