Merge pull request #38 from javierav/assets-helper

Add assets helpers to rails views

Author: excid3

CHANGELOG.md

@@ -22,6 +22,15 @@ FerrumPdf.render_pdf(url: "https://example.org", browser: Ferrum::Browser.new)
   * Remove `protocol` option
   * Rename `host` to `base_url`
 
+* Add assets helpers to Rails views for dealing with Chrome quirks.
+  https://nathanfriend.com/2019/04/15/pdf-gotchas-with-headless-chrome.html
+
+```ruby
+ferrum_pdf_inline_stylesheet("application.css")
+ferrum_pdf_inline_javascript("application.js")
+ferrum_pdf_base64_asset("logo.svg")
+```
+
 ### 0.3.0
 
 * Add `FerrumPdf.include_controller_module = false` option to skip adding `render_pdf` Rails helper

lib/ferrum_pdf.rb

@@ -9,9 +9,11 @@ module FerrumPdf
     <div class='text right'><span class='pageNumber'></span>/<span class='totalPages'></span></div>
   HTML
 
+  autoload :AssetsHelper, "ferrum_pdf/assets_helper"
   autoload :Controller, "ferrum_pdf/controller"
   autoload :HTMLPreprocessor, "ferrum_pdf/html_preprocessor"
 
+  mattr_accessor :include_assets_helper_module, default: true
   mattr_accessor :include_controller_module, default: true
   mattr_accessor :browsers, default: {}
   mattr_accessor :config, default: ActiveSupport::OrderedOptions.new.merge(

lib/ferrum_pdf/assets_helper.rb

@@ -0,0 +1,65 @@
+module FerrumPdf
+  module AssetsHelper
+    class BaseAsset
+      def initialize(asset)
+        @asset = asset
+      end
+    end
+
+    class PropshaftAsset < BaseAsset
+      def content_type
+        @asset.content_type.to_s
+      end
+
+      def content
+        @asset.content
+      end
+    end
+
+    class SprocketsAsset < BaseAsset
+      def content_type
+        @asset.content_type
+      end
+
+      def content
+        @asset.source
+      end
+    end
+
+    class AssetFinder
+      class << self
+        def find(path)
+          if Rails.application.assets.respond_to?(:load_path)
+            propshaft_asset(path)
+          elsif Rails.application.assets.respond_to?(:find_asset)
+            sprockets_asset(path)
+          else
+            nil
+          end
+        end
+
+        def propshaft_asset(path)
+          (asset = Rails.application.assets.load_path.find(path)) ? PropshaftAsset.new(asset) : nil
+        end
+
+        def sprockets_asset(path)
+          (asset = Rails.application.assets.find_asset(path)) ? SprocketsAsset.new(asset) : nil
+        end
+      end
+    end
+
+    def ferrum_pdf_inline_stylesheet(path)
+      (asset = AssetFinder.find(path)) ? "<style>#{asset.content}</style>".html_safe : nil
+    end
+
+    def ferrum_pdf_inline_javascript(path)
+      (asset = AssetFinder.find(path)) ? "<script>#{asset.content}</script>".html_safe : nil
+    end
+
+    def ferrum_pdf_base64_asset(path)
+      return nil unless (asset = AssetFinder.find(path))
+
+      "data:#{asset.content_type};base64,#{Base64.encode64(asset.content).gsub(/\s+/, '')}"
+    end
+  end
+end

lib/ferrum_pdf/railtie.rb

@@ -1,5 +1,11 @@
 module FerrumPdf
   class Railtie < ::Rails::Railtie
+    initializer "ferrum_pdf.assets_helper" do
+      ActiveSupport.on_load(:action_view) do
+        include FerrumPdf::AssetsHelper if FerrumPdf.include_assets_helper_module
+      end
+    end
+
     initializer "ferrum_pdf.controller" do
       ActiveSupport.on_load(:action_controller) do
         include FerrumPdf::Controller if FerrumPdf.include_controller_module