add tag autocompletion

lib/philomena_web/controllers/tag/autocomplete_controller.ex

@@ -0,0 +1,41 @@
+defmodule PhilomenaWeb.Tag.AutocompleteController do
+  use PhilomenaWeb, :controller
+
+  alias Philomena.Tags.Tag
+
+  def show(conn, params) do
+    tags =
+      case query(params) do
+        nil ->
+          []
+
+        term ->
+          Tag.search_records(
+            %{
+              query: %{
+                bool: %{
+                  should: [
+                    %{prefix: %{name: term}},
+                    %{prefix: %{name_in_namespace: term}}
+                  ]
+                }
+              },
+              sort: %{images: :desc}
+            },
+            %{page_size: 5},
+            Tag
+          )
+          |> Enum.map(&%{label: "#{&1.name} (#{&1.images_count})", value: &1.name})
+      end
+
+    conn
+    |> json(tags)
+  end
+
+  defp query(%{"term" => term}) when is_binary(term) and byte_size(term) > 2 do
+    term
+    |> String.downcase()
+    |> String.trim()
+  end
+  defp query(_params), do: nil
+end

lib/philomena_web/router.ex

@@ -90,6 +90,9 @@ defmodule PhilomenaWeb.Router do
       resources "/tag_changes", Image.TagChangeController, only: [:index]
       resources "/source_changes", Image.SourceChangeController, only: [:index]
     end
+    scope "/tags", Tag, as: :tag do
+      resources "/autocomplete", AutocompleteController, only: [:show], singleton: true
+    end
     resources "/tags", TagController, only: [:index, :show]
     resources "/search", SearchController, only: [:index]
     resources "/forums", ForumController, only: [:index, :show] do

lib/philomena_web/templates/tag/_tag_editor.html.slime

@@ -8,7 +8,7 @@ elixir:
 .js-tag-block class="fancy-tag-#{@type}"
   = textarea @f, @name, html_options
   .js-taginput.input.input--wide.tagsinput.hidden class="js-taginput-fancy" data-click-focus=".js-taginput-input.js-taginput-#{@name}"
-    input.input class="js-taginput-input js-taginput-#{@name}" id="taginput-fancy-#{@name}" type="text" placeholder="add a tag" autocapitalize="none" data-ac="true" data-ac-min-length="3" data-ac-source='/tags/autocomplete.json?term='
+    input.input class="js-taginput-input js-taginput-#{@name}" id="taginput-fancy-#{@name}" type="text" placeholder="add a tag" autocapitalize="none" data-ac="true" data-ac-min-length="3" data-ac-source='/tags/autocomplete?term='
 button.button.button--state-primary.button--bold class="js-taginput-show" data-click-show=".js-taginput-fancy,.js-taginput-hide" data-click-hide=".js-taginput-plain,.js-taginput-show" data-click-focus=".js-taginput-input.js-taginput-#{@name}"
   = hidden_input :fuck_ie, :fuck_ie, value: "fuck_ie"
   ' Fancy Editor