Dynamically load the thumbnail list

This ensures the edit page can load quickly

app/assets/javascripts/hyrax/admin/admin_set_controls.es6

@@ -1,5 +1,7 @@
 export default class {
   constructor(elem) {
+    this.loadThumbnailOptions(elem)
+
     let Participants = require('hyrax/admin/admin_set/participants');
     let participants = new Participants(elem.find('#participants'))
     participants.setup();
@@ -8,4 +10,24 @@ export default class {
     let visibilityTab = new Visibility(elem.find('#visibility'));
     visibilityTab.setup();
   }
+
+  // Dynamically load the file options into the "Thumbnail" select field.
+  loadThumbnailOptions(elem) {
+      let url = window.location.pathname.replace('edit', 'files')
+      elem.find('#admin_set_thumbnail_id').select2({
+          ajax: { // Use the jQuery.ajax wrapper provided by Select2
+              url: url,
+              dataType: "json",
+              results: function(data, page) {
+                return { results: data }
+              }
+          },
+          initSelection: function(element, callback) {
+              // the input tag has a value attribute preloaded that points to a preselected repository's id
+              // this function resolves that id attribute to an object that select2 can render
+              // using its formatResult renderer - that way the repository name is shown preselected
+              callback({ text: $(element).data('text') })
+          }
+      })
+  }
 }

app/controllers/hyrax/admin/admin_sets_controller.rb

@@ -44,6 +44,16 @@ def edit
       setup_form
     end
 
+    # Renders a JSON response with a list of files in this admin set.
+    # This is used by the edit form
+    def files
+      form = form_class.new(@admin_set)
+      result = form.select_files.map do |label, id|
+        { id: id, text: label }
+      end
+      render json: result
+    end
+
     def update
       if @admin_set.update(admin_set_params)
         redirect_to hyrax.edit_admin_admin_set_path(@admin_set), notice: I18n.t('updated_admin_set', scope: 'hyrax.admin.admin_sets.form.permission_update_notices', name: @admin_set.title.first)

app/forms/hyrax/forms/admin_set_form.rb

@@ -22,6 +22,11 @@ def permission_template
                                  end
       end
 
+      def thumbnail_title
+        return unless model.thumbnail
+        model.thumbnail.title.first
+      end
+
       class << self
         # This determines whether the allowed parameters are single or multiple.
         # By default it delegates to the model.

app/views/hyrax/admin/admin_sets/_form.html.erb

@@ -23,7 +23,9 @@
                 <%= render 'form_metadata', f: f %>
 
                 <% if f.object.persisted? && f.object.member_ids.present? %>
-                  <%= f.input :thumbnail_id, collection: @form.select_files %>
+                  <%# we're loading these values dynamically to speed page load %>
+                  <%= f.input :thumbnail_id,
+                              input_html: { data: { text: f.object.thumbnail_title } } %>
                 <% end %>
 
               </div>

config/routes.rb

@@ -186,6 +186,9 @@
 
   namespace :admin do
     resources :admin_sets do
+      member do
+        get :files
+      end
       resource :permission_template
     end
     resources :users, only: [:index]

spec/controllers/hyrax/admin/admin_sets_controller_spec.rb

@@ -13,8 +13,6 @@
     end
 
     describe "#new" do
-      let!(:admin_set) { create(:admin_set) }
-
       it 'is unauthorized' do
         get :new
         expect(response).to be_redirect
@@ -32,6 +30,14 @@
         end
       end
     end
+
+    describe "#files" do
+      let(:admin_set) { create(:admin_set) }
+      it 'is unauthorized' do
+        get :files, params: { id: admin_set }, format: :json
+        expect(response).to be_unauthorized
+      end
+    end
   end
 
   context "as an admin" do
@@ -111,6 +117,14 @@
       end
     end
 
+    describe "#files" do
+      let(:admin_set) { create(:admin_set, edit_users: [user]) }
+      it 'shows a list of member files' do
+        get :files, params: { id: admin_set }, format: :json
+        expect(response).to be_success
+      end
+    end
+
     describe "#update" do
       let(:admin_set) { create(:admin_set, edit_users: [user]) }
       it 'updates a record' do

spec/forms/hyrax/forms/admin_set_form_spec.rb

@@ -9,6 +9,21 @@
     end
   end
 
+  describe "#thumbnail_title" do
+    subject { form.thumbnail_title }
+
+    context "when the admin_set has a thumbnail" do
+      let(:thumbnail) { stub_model(FileSet, title: ['Ulysses']) }
+      let(:model) { AdminSet.new(thumbnail: thumbnail) }
+      it { is_expected.to eq "Ulysses" }
+    end
+
+    context "when the admin_set has no thumbnail" do
+      let(:model) { AdminSet.new }
+      it { is_expected.to be nil }
+    end
+  end
+
   describe "#permission_template" do
     subject { form.permission_template }
     context "when the PermissionTemplate doesn't exist" do

spec/views/hyrax/admin/admin_sets/_form.html.erb_spec.rb

@@ -2,13 +2,18 @@
 
 RSpec.describe 'hyrax/admin/admin_sets/_form.html.erb', type: :view do
   let(:admin_set) { stub_model(AdminSet) }
+  let(:form) { Hyrax::Forms::AdminSetForm.new(admin_set) }
+
   before do
-    @form = Hyrax::Forms::AdminSetForm.new(admin_set)
+    assign(:form, form)
     stub_template('hyrax/admin/admin_sets/_form_participants.html.erb' => 'participant tab')
     stub_template('hyrax/admin/admin_sets/_form_visibility.html.erb' => 'visibility tab')
     stub_template('hyrax/admin/admin_sets/_form_workflow.html.erb' => 'workflow tab')
+    allow(form).to receive(:thumbnail_title).and_return("James Joyce")
+    allow(admin_set).to receive(:member_ids).and_return(['123', '456'])
     render
   end
+
   it "has 4 tabs" do
     expect(rendered).to have_selector('#description')
     expect(rendered).to have_content('participant tab')
@@ -18,6 +23,7 @@
     # metadata fields
     expect(rendered).to have_selector('input[type=text][name="admin_set[title]"]')
     expect(rendered).to have_selector('textarea[name="admin_set[description]"]')
+    expect(rendered).to have_selector('input[type=text][name="admin_set[thumbnail_id]"][data-text="James Joyce"]')
 
     # hint text
     expect(rendered).to have_content("A name to aid in identifying the Administrative Set and to distinguish it from other Administrative Sets in the repository.")