init project

app/controllers/concerns/render_expand.rb

@@ -0,0 +1,40 @@
+module RenderExpand
+  extend ActiveSupport::Concern
+
+  included do
+    ActionController.add_renderer :pdf do |template, options|
+      file = File.open(Rails.root.join('app/templates', template << '.html.erb'))
+      html = ERB.new(file.read).result(binding)
+      kit = PDFKit.new(html)
+
+      base_css = %w(app/templates/shared/main.css)
+      base_css.each { |css| kit.stylesheets << Rails.root.join(css) }
+
+      Array.wrap(options.delete(:stylesheets)).each do |path|
+        kit.stylesheets << Rails.root.join('app/templates', path)
+      end
+
+      send_data kit.to_pdf, filename: options[:filename], disposition: options[:disposition] || 'attachment', type: 'application/pdf'
+    end
+
+
+    ActionController.add_renderer :exam_pdf do |template, options|
+      file = File.open(Rails.root.join('app/templates', template << '.html.erb'))
+      html = ERB.new(file.read).result(binding)
+      kit = PDFKit.new(html)
+
+      # PDFKit初始化后再添加样式文件到stylesheets，会出现在页面的<!DOCTYPE>定义不起作用，文档模式为默认为BackCompat，从而导致katex不起作用
+      # 而测试发现通过配置添加css样式文件不会有影响
+      PDFKit.configure do |config|
+        config.default_options = {
+          :"user-style-sheet" =>  Rails.root.join('app/templates', options[:stylesheets])
+        }
+      end
+
+      send_data kit.to_pdf, filename: options[:filename], disposition: options[:disposition] || 'attachment', type: 'application/pdf'
+    end
+  end
+
+
+
+end