ruby-on-rails – 如何让Rails为PDFKit呈现PDF特定的HTML？

弄清楚了.根据the Rails source,request.format =’pdf’将手动将响应格式设置为PDF.这意味着Rails将渲染,例如show.pdf.haml.

但是,现在PDFKit不会将响应转换为实际的PDF,因为当我们实际上只生成HTML时,Content-Type标题表明它已经是PDF.所以我们还需要覆盖Rails的响应标头,说它仍然是HTML.

这个控制器方法处理它：

# By default,when PDF format is requested,PDFKit's middleware asks the app
# to respond with HTML. If we actually need to generate different HTML based
# on the fact that a PDF was requested,this method reverts us back to the
# normal Rails `respond_to` for PDF.
def use_pdf_specific_template
  return unless env['Rack-Middleware-PDFKit']

  # Tell the controller that the request is for PDF so it 
  # will use a PDF-specific template
  request.format = 'pdf'
  # Tell PDFKit that the response is HTML so it will convert to PDF
  response.headers['Content-Type'] = 'text/html'
end

这意味着控制器操作如下所示：

def show
  @invoice = Finance::Invoice.get!(params[:id])

  # Only call this if PDF responses should not use the same templates as HTML
  use_pdf_specific_template

  respond_to do |format|
    format.html
    format.pdf
  end
end