Render and combine PDF files into one

Render PDF files from HTML templates in Rails can be done using WickedPDF.

First you need to use ActionView to render HTML to a string:

def render_to_string(data)

  action_view = ActionView::Base.new

  action_view.view_paths = ActionController::Base.view_paths



  action_view.class_eval do

    include ApplicationHelper

    include PDFHelper

    # or other helpers

  end



  action_view.render template: 'pdf/template.html',

                     layout: 'layout/pdf.html',

                     locals: { data: data }

end

Then you can render pdf with the desired settings like this:

# first pdf file with some view settings and values from data1...

pdf1 = WickedPdf.new.pdf_from_string(

        render_to_string(data1), {

            pdf: 'report1',

            page_size: 'Letter',

            orientation: 'Portrait'

        })

# ...and second pdf file with some view settings and values from data2

pdf2 = WickedPdf.new.pdf_from_string(

        render_to_string(data2), {

            pdf: 'report2',

            page_size: 'Letter',

            orientation: 'Landscape'

        })

And now you can combine it with CombinePDF gem, that provide you parse method to get PDF content and to_pdfmethod to render the result back to PDF.

combiner = CombinePDF.new

combiner << CombinePDF.parse(pdf1)

combiner << CombinePDF.parse(pdf2)

combiner.to_pdf