NoMethodError: undefined method `downcase' for nil:NilClass

[olegsobchuk]

Hi, I've tried merge document with next steps

target = HexaPDF::Document.new
['/path/to/my/file.pdf')].each do |file|
   pdf = HexaPDF::Document.open(file)
   pdf.pages.each_page {|page| target.pages.add_page(target.import(page))}
end

target.write("merging.pdf", optimize: true)

but it raise:

NoMethodError: undefined method `downcase' for nil:NilClass
from /my/path/gems/hexapdf-0.1.0/lib/hexapdf/serializer.rb:91:in `block (2 levels) in initialize'

[gettalong]

This should definitely not happen. However, without the source PDF I can't really do much - can you provide it?

[olegsobchuk]

I've tried with different documents, all raise same error. For example I took this https://wwwimages2.adobe.com/www.adobe.com/content/dam/Adobe/ru/legal/licenses-terms/pdf/PlatformClients_PC_WWEULA-ru_RU-20150407_1357.pdf file

[gettalong]

I have tried with your provided document and it works fine. Which Ruby version are you using? Try Ruby 2.3 if you are not using it.

[olegsobchuk]

I'm using

$ ruby -v
ruby 2.3.1p112 (2016-04-26 revision 54768) [x86_64-linux]
$ rails -v
Rails 5.0.0.1

[gettalong]

Rails version should be irrelevant since the code you presented didn't have anything to do with Rails. However, if this was not the case, try using the code without Rails and see if it works then.

[gaga5lala]

I've test merge method with the file provided by @olegsobchuk at both ruby and rails environment, it's work fine.

• ruby 2.3.0p0 (2015-12-25 revision 53290) [x86_64-darwin15]
• Rails 4.2.5.2

[gettalong]

@gaga5lala Thanks!

[olegsobchuk]

I don't know why but in HexaPDF::Serializer in initializer when I run klass.ancestors it shows me

 => [#<Module:0x00000006e79d10>,
 ActiveSupport::NumericWithFormat,
 Fixnum,
 JSON::Ext::Generator::GeneratorMethods::Fixnum,
 ActiveSupport::ToJsonWithActiveSupportEncoder,
 Integer,
 Numeric,
 Comparable,
 ActiveSupport::ToJsonWithActiveSupportEncoder,
 Object,
 PP::ObjectMixin,
 ActiveSupport::Dependencies::Loadable,
 JSON::Ext::Generator::GeneratorMethods::Object,
 ActiveSupport::Tryable,
 Kernel,
 BasicObject]

as you can see there is Module and that makes error

BTW

it works in pure ruby (in irb)

[gettalong]

Okay, so it seems we found the culprit, namely ActiveSupport prepending modules to built-in classes which shouldn't be done globally - that's what refinements are for.

[gettalong]

@olegsobchuk @gaga5lala I have updated the serialization implementation to work around this problem. Please try the code from Github and see if it works with your setup.