Sometimes, when extracting a content type from a custom module, you may want to include fields associated with that content type. Automatically creating fields allows you to remove and reinstall on multiple sites without leaving behind unnecessary fields and ensures you don’t forget to add them. There are two ways to add these fields to your codebase, which we’ll cover here.

Significant Improvement

• The Entity API now implements the Typed Data API

In this new implementation, the Entity API treats everything as a field based on the same API, making entities predictable and consistent.

Placeholder landing page, just to outline the various child pages we’ll need.

For now, see: https://api.drupal.org/api/drupal/core%21lib%21Drupal%21Core%21Entity%21entity.api.php/group/entity_api/8.

Defining and Using Content Entity Field Definitions

Content entities must explicitly define all their fields by providing field definitions in the entity class. Field definitions are based on the Typed Data API (see also How Entities Implement It).

In Drupal 8, field language is no longer exposed via the public API. Instead, fields are attached to language-aware objects from which they "inherit" their language.

The key benefits here are:

Display Modes

There are display modes (available at admin/Structure/Display-Mode) that provide different views of content entities for viewing or editing. The two types of display modes are "view modes" and "form modes." Both of these — view modes and form modes — are examples of configuration entities. Here’s an example of an exported view mode.

This tutorial was originally published on Web Wash. However, Berdir asked if I could post the tutorial here, so here it is.

The module in Drupal 7 allows you to store code samples/snippets in a field. It comes with a customizable field called “Snippets field” and displays three form elements: description, source code, and syntax highlighting mode (which programming language).

But now it's time to upgrade the module to Drupal 8.

Overview

Drupal 8 comes with a large library of base classes that allow you to work with your own content. When it comes to content entities, you want to use fields. It is important to understand Fields, as this is where your entities store their data.

FieldTypes

Main field types:

Authentication for CRUD Operations with JSON:API

When interacting with the JSON:API, tools such as Postman or cURL can be used to send requests. By default, requests made through these tools are treated as coming from an "anonymous" user, since they do not inherently manage user authentication. As a result, access to certain resources may be restricted based on the permissions configured for anonymous users in your Drupal site.

If you are looking to protect/restrict access to your Drupal REST APIs using your Identity provider, then you should go for the External Identity Provider Authentication method. 

Drupal API Authentication using an External Identity Provider involves the use of tokens received from third-party providers like Google, Azure AD, Keycloak, Okta, Gitlab, etc. for accessing Drupal rest APIs securely.