Often times you may need to use information from a page inside of a layout.
A common usecase are javascript files particular to a page.
You can use the page variable within any layout to access any data particular to a page.
Using the JavaScript example if you wanted to add scripts to a layout, the easiest thing to do would be to add the script URLs to the front_matter of the page:
page.md
--- title: My Page scripts: [http://.../blah.js, http://.../bar.js] --- Page content
_layouts/base.slim
...
- page.front_matter.scripts.each do |url|
script href=url
You may have other sections or variables on a page that you need, but this is the basics. If you need something in a page or layout, the easiest way to do this is to add it to the front-matter of the page.