Generator plugin doesn't render data - jekyll

Question

I am writing a jekyll plugin to render an alternative layout for my posts in category "portfolio". The files are generated in the partial folder but the data is not rendered. What am I doing wrong?
Generator:
module Jekyll
class PartialGenerator < Generator
def generate(site)
site.categories['portfolio'].each do |post|
site.pages << PartialPage.new(site, site.source, post)
end
end
end
class PartialPage < Page
def initialize(site, base, post)
#site = site
#base = base
#dir = 'partials'
#name = "#{post.id}.html".tr('/','')
self.process(name)
self.read_yaml(File.join(base, '_layouts'), "partial.html")
self.data['page'] = post
end
end
end
The partial.html layout includes <h1>{{ page.title }}</h1> and the generated output is <h1></h1>
I've tried puts(post.title) in the initialize method and it prints the correct titles on the console.

Answer 1

I found the solution myself now.
The data you put into self.data[]is available as property of page in the template/layout.
So self.data[‘test'] = "..." can be accessed through {{page.test}}.
Now my generator includes self.data['page'] = post and I access it in my partial.html as <h1>{{page.post.title}}</h1>.