Rails 4 wicked_pdf generate blank pdf while generating from model - ruby-on-rails-4

Question

I'm trying to save pdf on server using rails model buts its generate a blank pdf. Earlier did it in controller without problem but now its creating a blank one. Any idea What's i did wrong?
def generate_bulk_pdf
view = ActionView::Base.new(ActionController::Base.view_paths, {})
view.extend(ApplicationHelper)
view.extend(AbstractController::Rendering)
view.extend(Rails.application.routes.url_helpers)
students = Student.all.order('id ASC')
students.each do | aStudent |
pdf = WickedPdf.new.pdf_from_string(
view.render_to_string(
:template => "#{Rails.root.join('templates/challen.pdf.erb')}",
:locals => { '#student' => aStudent }
)
)
save_path = Rails.root.join('pdfs','filename.pdf')
File.open(save_path, 'wb') do |file|
file << pdf
end
end
end
Any idea What's i did wrong? I can't find any solution

Answer 1

A good test is just put a simple line of text in your template and see if you get a PDF with that line. Strip everything back so you just generating a PDF with no coming locals, just that 1 string and let me know.
Here is how I set up mine and it works fine, it might click something :)
def generate_pdf_voucher(voucher, dir_name)
view = ActionView::Base.new(Rails.root.join('app/views'))
view.class.include ApplicationHelper
view.class.include Rails.application.routes.url_helpers
pdf = view.render :pdf => a_name,
:template => 'layouts/pdfs/voucher_pdf',
:layout => 'layouts/pdfs/pdf.html.erb',
:header => {:right => '[page] of [topage]'},
:locals => {:#voucher => voucher}
# then save to a file
pdf = WickedPdf.new.pdf_from_string(pdf)
save_path = Rails.root.join('public', 'pdfs', dir_name, "#{voucher[:user].id.to_s}.pdf")
File.open(save_path, 'wb') do |file|
file << pdf
end
end
pdf.html.erb is the structure of the PDF
voucher_pdf is all the dynamic stuff
If this wasn't helpful, then put a comment on and I will delete it.