Template variables

Drupal 8 uses variables to output data within Twig templates. We know that variables generally consist of anything from a simple string to a complex object containing an array of values. If we look at the html.html.twig template, we will see documentation that outlines the variables available to us along with the name of the variable and a description of what the variable contains.

The list of variables is as follows:

• logged_in: A flag indicating whether the user is logged in
• root_path: The root path of the current page (for example, node, admin, and user)
• node_type: The content type for the current node, if the page is a node
• head_title: List of text elements that make up the head_title variable
• title: The title of the page
• name: The name of the site
• slogan: The slogan of the site
• page_top: Initial rendered markup; this should be printed before page
• page: The rendered page markup
• page_bottom: Closing rendered markup; this variable should be printed after page
• db_offline: A flag...