Optionally preload async comboboxes (#224)

app/presenters/hotwire_combobox/component.rb

@@ -26,12 +26,13 @@ def initialize(
     name_when_new: nil,
     open: false,
     options: [],
+    preload: false,
     request: nil,
     value: nil, **rest)
     @view, @autocomplete, @id, @name, @value, @form, @async_src, @label, @free_text, @request,
-    @name_when_new, @open, @data, @mobile_at, @multiselect_chip_src, @options, @dialog_label =
+    @preload, @name_when_new, @open, @data, @mobile_at, @multiselect_chip_src, @options, @dialog_label =
       view, autocomplete, id, name.to_s, value, form, async_src, label, free_text, request,
-      name_when_new, open, data, mobile_at, multiselect_chip_src, options, dialog_label
+      preload, name_when_new, open, data, mobile_at, multiselect_chip_src, options, dialog_label
 
     @combobox_attrs = input.reverse_merge(rest).deep_symbolize_keys
     @association_name = association_name || infer_association_name
@@ -46,7 +47,7 @@ def render_in(view_context, &block)
 
   private
     attr_reader :view, :autocomplete, :id, :name, :value, :form, :free_text, :open, :request,
-      :data, :combobox_attrs, :mobile_at, :association_name, :multiselect_chip_src
+      :data, :combobox_attrs, :mobile_at, :association_name, :multiselect_chip_src, :preload
 
     def canonical_id
       @canonical_id ||= id || form&.field_id(name) || SecureRandom.uuid

app/presenters/hotwire_combobox/component/paginated.rb

@@ -4,6 +4,15 @@ def paginated?
   end
 
   def pagination_attrs
-    { for_id: canonical_id, src: async_src }
+    { for_id: canonical_id, src: async_src, loading: preload_next_page? ? :eager : :lazy }
   end
+
+  private
+    def preload_next_page?
+      view.hw_first_page? && preload?
+    end
+
+    def preload?
+      preload.present?
+    end
 end

app/views/hotwire_combobox/_pagination.html.erb

@@ -1,7 +1,7 @@
-<%# locals: (for_id:, src:) -%>
+<%# locals: (for_id:, src:, loading: :lazy) -%>
 
 <%= tag.li id: hw_pagination_frame_wrapper_id(for_id), class: "hw_combobox__pagination__wrapper",
       data: { hw_combobox_target: "endOfOptionsStream", input_type: params[:input_type], callback_id: params[:callback_id] },
       aria: { hidden: true } do %>
-  <%= turbo_frame_tag hw_pagination_frame_id(for_id), src: src, loading: :lazy %>
+  <%= turbo_frame_tag hw_pagination_frame_id(for_id), src: src, loading: loading %>
 <% end %>

lib/hotwire_combobox/helper.rb

@@ -25,7 +25,7 @@ def hw_combobox_options(options, render_in: {}, include_blank: nil, display: :to
     end
 
     def hw_paginated_combobox_options(options, for_id: params[:for_id], src: hw_fullpath_for_pagination, next_page: nil, render_in: {}, include_blank: {}, **custom_methods)
-      include_blank = params[:page].to_i > 0 ? nil : include_blank
+      include_blank = hw_first_page? ? include_blank : nil
       options = hw_combobox_options options, render_in: render_in, include_blank: include_blank, **custom_methods
       this_page = render "hotwire_combobox/paginated_options", for_id: for_id, options: options
       next_page = render "hotwire_combobox/next_page", for_id: for_id, src: hw_combobox_next_page_uri(src, next_page, for_id)
@@ -106,7 +106,11 @@ def hw_pagination_frame_id(id)
       end
 
       def hw_combobox_page_stream_action
-        params[:page].to_i > 0 ? :append : :update
+        hw_first_page? ? :update : :append
+      end
+
+      def hw_first_page?
+        params[:page].to_i.zero?
       end
 
       def hw_uri_with_params(url_or_path, **params)

test/dummy/app/controllers/comboboxes_controller.rb

@@ -34,6 +34,9 @@ def list_autocomplete
   def async
   end
 
+  def async_preload
+  end
+
   def freetext_async
   end
 

test/dummy/app/views/comboboxes/async_preload.html.erb

@@ -0,0 +1 @@
+<%= combobox_tag "movie", movies_path, id: "movie-field", label: "Choose your movie!", preload: true %>

test/dummy/config/routes.rb

@@ -1,39 +1,40 @@
 Rails.application.routes.draw do
-  get "plain", to: "comboboxes#plain"
-  get "padded", to: "comboboxes#padded"
-  get "open", to: "comboboxes#open"
-  get "html_options", to: "comboboxes#html_options"
-  get "prefilled", to: "comboboxes#prefilled"
-  get "prefilled_html", to: "comboboxes#prefilled_html"
-  get "required", to: "comboboxes#required"
-  get "formbuilder", to: "comboboxes#formbuilder"
-  get "new_options", to: "comboboxes#new_options"
-  get "inline_autocomplete", to: "comboboxes#inline_autocomplete"
-  get "list_autocomplete", to: "comboboxes#list_autocomplete"
   get "async", to: "comboboxes#async"
-  get "freetext_async", to: "comboboxes#freetext_async"
-  get "prefilled_async", to: "comboboxes#prefilled_async"
-  get "prefilled_form", to: "comboboxes#prefilled_form"
-  get "prefilled_free_text", to: "comboboxes#prefilled_free_text"
   get "async_html", to: "comboboxes#async_html"
-  get "render_in", to: "comboboxes#render_in"
+  get "async_preload", to: "comboboxes#async_preload"
+  get "conflicting_order", to: "comboboxes#conflicting_order"
+  get "custom_attrs", to: "comboboxes#custom_attrs"
+  get "custom_events", to: "comboboxes#custom_events"
+  get "dialog", to: "comboboxes#dialog"
   get "enum", to: "comboboxes#enum"
+  get "external_clear", to: "comboboxes#external_clear"
+  get "form_object", to: "comboboxes#form_object"
+  get "formbuilder", to: "comboboxes#formbuilder"
+  get "freetext_async", to: "comboboxes#freetext_async"
+  get "grouped_options", to: "comboboxes#grouped_options"
+  get "html_options", to: "comboboxes#html_options"
   get "include_blank", to: "comboboxes#include_blank"
-  get "custom_events", to: "comboboxes#custom_events"
-  get "custom_attrs", to: "comboboxes#custom_attrs"
-  get "conflicting_order", to: "comboboxes#conflicting_order"
-  get "render_in_locals", to: "comboboxes#render_in_locals"
+  get "inline_autocomplete", to: "comboboxes#inline_autocomplete"
+  get "list_autocomplete", to: "comboboxes#list_autocomplete"
+  get "morph", to: "comboboxes#morph"
   get "multiselect", to: "comboboxes#multiselect"
-  get "multiselect_dismissing", to: "comboboxes#multiselect_dismissing"
   get "multiselect_async_html", to: "comboboxes#multiselect_async_html"
-  get "multiselect_prefilled_form", to: "comboboxes#multiselect_prefilled_form"
   get "multiselect_custom_events", to: "comboboxes#multiselect_custom_events"
+  get "multiselect_dismissing", to: "comboboxes#multiselect_dismissing"
   get "multiselect_new_values", to: "comboboxes#multiselect_new_values"
-  get "grouped_options", to: "comboboxes#grouped_options"
-  get "morph", to: "comboboxes#morph"
-  get "form_object", to: "comboboxes#form_object"
-  get "external_clear", to: "comboboxes#external_clear"
-  get "dialog", to: "comboboxes#dialog"
+  get "multiselect_prefilled_form", to: "comboboxes#multiselect_prefilled_form"
+  get "new_options", to: "comboboxes#new_options"
+  get "open", to: "comboboxes#open"
+  get "padded", to: "comboboxes#padded"
+  get "plain", to: "comboboxes#plain"
+  get "prefilled", to: "comboboxes#prefilled"
+  get "prefilled_async", to: "comboboxes#prefilled_async"
+  get "prefilled_form", to: "comboboxes#prefilled_form"
+  get "prefilled_free_text", to: "comboboxes#prefilled_free_text"
+  get "prefilled_html", to: "comboboxes#prefilled_html"
+  get "render_in", to: "comboboxes#render_in"
+  get "render_in_locals", to: "comboboxes#render_in_locals"
+  get "required", to: "comboboxes#required"
 
   resources :movies, only: %i[ index update ]
   get "movies_html", to: "movies#index_html"

test/system/async_test.rb

@@ -54,4 +54,9 @@ class AsyncTest < ApplicationSystemTestCase
     click_on_option "A Few Good Men"
     assert_combobox_display_and_value "#movie-field", "A Few Good Men", movies(:a_few_good_men).id
   end
+
+  test "preload" do
+    visit async_preload_path
+    assert_options_with count: 5, visible: :hidden
+  end
 end