Change timing to get image size

app/controllers/admin/custom_emojis_controller.rb

@@ -1,7 +1,5 @@
 # frozen_string_literal: true
 
-require 'fastimage'
-
 module Admin
   class CustomEmojisController < BaseController
     def index
@@ -20,11 +18,7 @@ module Admin
     def create
       authorize :custom_emoji, :create?
 
-      image_size = FastImage.size(params[:custom_emoji][:image])
-
       @custom_emoji = CustomEmoji.new(resource_params)
-      @custom_emoji.image_width = image_size[0]
-      @custom_emoji.image_height = image_size[1]
 
       if @custom_emoji.save
         log_action :create, @custom_emoji

app/models/custom_emoji.rb

@@ -56,6 +56,8 @@ class CustomEmoji < ApplicationRecord
 
   after_commit :remove_entity_cache
 
+  after_post_process :set_size
+
   def local?
     domain.nil?
   end
@@ -99,4 +101,15 @@ class CustomEmoji < ApplicationRecord
   def downcase_domain
     self.domain = domain.downcase unless domain.nil?
   end
+
+  def set_size
+    image.queued_for_write.each do |style, file|
+      if style == :original
+        image_size = FastImage.size(file.path)
+        self.image_width = image_size[0]
+        self.image_height = image_size[1]
+        return
+      end
+    end
+  end
 end