Drupal User Guide
Guide
YAML, which stands for YAML Ain't Markup Language, is a human-readable data serialization format that's been widely adopted in a variety of use cases in Drupal. Anyone wanting to write modules, or themes, for Drupal will need to understand YAML syntax. Even site builders are likely to encounter YAML at least in passing as YAML is the data-serialization format of choice for Drupal's configuration management system. Good thing it's pretty easy to learn even with the most basic of programming backgrounds.
This tutorial will look at the YAML data format and provide examples of how to write and read YAML. Starting with an introduction to the language's syntax and some of the strengths of YAML. Then looking at the difference between scalar data types like strings and integers, and collection data types like lists and associative arrays.
Since YAML in the Drupal world is read into PHP and ultimately becomes a PHP data structure that we can use in our own code we'll also look at how the YAML we write in a .yml file is represented in PHP data types. To do this we'll use the YAML Sandbox module that provides a handy textarea into which we can type YAML and have it parsed into PHP data structures.
Learning objectives
- Explain what YAML is and its strengths as a data serialization format
- Create scalar key/value pairs in YAML
- Create lists, and associative arrays using YAML collections
- Understand how the YAML you write is represented in PHP
Tips
- In Drupal, use the .yml extension and not .yaml
- Ensure your code editing application is configured to use spaces (preferably 2 spaces, as per Drupal coding standards), not the tab character when the TAB key is pressed. If you have tab characters in a YAML file within a Drupal environment, a fatal PHP error will be thrown and you'll see a White Screen of Death (WSOD).
- Copy and paste from an existing YAML file to ensure the formatting is correct, and edit from there.
Additional resources
- http://www.yaml.org
- YAML Sandbox module
- Find other tutorials and external resources related to YAML on our YAML topic page (Drupalize.Me)
Object-Oriented PHP
TopicObject-oriented PHP utilizes classes and objects to organize code into reusable chunks. This approach helps us organize complex applications, such as Drupal, into modular code called classes that can be reused across the entire system.
Caching in Drupal
TopicCaching in Drupal is controlled by Drupal's Cache API which is used to store any type of data on a permanent or temporary basis. Some types of data tend to take a long time to compute, but utilizing the Cache API in your module can help your site load data more quickly.
Performance and scalability determine how fast your application can serve a page and to how many users at a time.
Symfony
TopicSymfony is a set of reusable PHP components, and a framework for building PHP applications. Drupal makes use of various Symfony components.
Overview of languages and translation on a site.
How to translate field labels in a view, and other configuration.
How to configure content items to make them translatable.
5.5. Concept: Menu
FreeOverview of the menu concept and menus automatically created with the core Standard installation profile.
How to configure a content item so that it gets displayed as the home page.
Overview of content entities and fields.
How to plan the navigation and layout of a website (mobile and desktop browsers).
Overview of modular content and how content in a page can be sourced from other content items.
How to plan a content structure that assigns content entity types to specific content on the website.
Overview of the editorial workflow to manage content on a website.