Introduction to the Views API

The Views module is a query generator and render engine in Drupal core. It’s typically used to create and output collections of items such as Drupal content entities. But it can also aggregate users, blocks, log records, and more. The output can be rendered many ways, including as a list, a grid, or an RSS feed. Views is commonly used in Drupal to create pages, blocks and other types of displays.

Through the Views API developers can expose new data to Views, add new configuration options, create new output plugins, field formatters, sort handlers, filter handlers, and more. By creating these customizations as extensions of Views instead of as stand alone queries, or hard-coded lists, you can empower site administrators to mix and match your customizations with the existing feature set in any way they might need.

In this tutorial we’ll:

• Get a high level overview of the Views API
• Discuss the Views API’s functional parts such as hooks, plugins, and data types
• Learn how to use the Views API in your project

By the end of this tutorial you’ll have a solid understanding of the parts of the Views API and some guidance on which to use for your goals.

Goal

Introduce the Views API and related concepts to Drupal developers who have site building experience with the Views module in Drupal.

Prerequisites

• Creating Listings with Views (Drupal User Guide)
• Views: Create Lists with Drupal
• What Are Plugins?
• What Are Hooks?

Views API defined

The Views module is developed with maximum flexibility and ease of use in mind. Most of the typical use cases for websites such as generating a list of events, grid of news cards, or page of search results can be accomplished using just Views.

In situations when the options provided by Drupal core and existing contributed modules are not enough, developers can utilize the Views API to add their own features. The API consists of a collection of plugin types and hooks exposed by the Views module and described within views.api.php file of the Views module in Drupal core. The Views API also covers a views render layer and describes a template naming convention and hierarchy that can be used to create template overrides within a theme.

Interact with the Views module

Views API allows developers to interact with the Views module in several different ways. One of the easiest ways is by using hooks. Some operations in Views can be influenced by hooks. Hooks also are invoked during every step of Views build and render process providing the opportunity for developers to influence the outcome of each step, alter output, or add conditions.

Hooks are also used to expose information to the view and extend or add new data types. In this case developers can use data hooks to provide data to the view.

Views plugins provide a more complex level of interaction with Views code compared to hooks. Plugins govern almost every aspect of Views, including querying, sorting, and filtering, as well as displaying and rendering of different components and a view as a whole. Views API allows for alteration and extension of default plugins, and outlines mechanisms to define custom plugins.