Block

The Block module is an essential part of Drupal’s architecture. It not only offers an intuitive UI for managing blocks but also provides a robust API for developers to create custom blocks and control their behavior. This guide covers everything you need to know about the Block module, from enabling and configuring blocks to leveraging the Block API for custom functionality.

1. Enabling and Managing Blocks

In Drupal core, the Block module is enabled by default. However, if you need to verify its status or re-enable it, you can do so through the Extend page (/admin/modules) or by using Drush:

drush en block -y

Once enabled, you can manage blocks by navigating to the Block layout page (/admin/structure/block). This interface allows you to see all available blocks and assign them to specific regions defined by your theme.

2. Creating Custom Blocks

Drupal allows you to create custom blocks that can hold any content you wish to display. To create a custom block:

Go to /admin/structure/block/block-content and click “Add custom block”.

By default if you dont have any block type created, you will see this empty page

Then we should create a new content type frist in order to be able to create custom content blocks, by clickin on block type creation page.

By clicking in save we will create the new content block type.

We could add any other type of fields following the manage field operation, just like content type fields. But, for now, we will return the add content block page. Fill in the fields for the block title and body, then save your custom block.

Custom blocks can be edited, deleted, and reused across different regions of your site.

3. Placing and Configuring Blocks

After creating or choosing an existing block, you need to place it within a region. From the Block layout page (we saw this page previously in the route /admin/structure/block.

Click on “Place block” next to the desired region.

Select the block you want to place and configure its settings, such as title visibility, CSS classes, and custom visibility conditions. Visibility settings allow you to restrict block display by content types, user roles, paths, and more. Just configurate it and save the configuration.

Once configured, the block will appear on the designated pages and regions according to your rules.

Now you only need to visit a route that accomplish visibility configuration and see your block placed.

4. Understanding Block Visibility and Caching

The Block module provides advanced options to control where and when a block is displayed:

• Visibility Settings: Configure conditions based on content types, pages, user roles, or custom PHP logic to determine if a block should be visible.
• Caching: Each block can have individual caching settings, which is crucial for optimizing site performance. You can control cache lifetime and context to ensure dynamic blocks update as needed while still benefiting from caching.

5. The Block API and Developer Customizations

For developers, the Block API offers powerful hooks and plugins to create and alter blocks:

• Block Plugin System: Custom blocks are defined as plugins that implement specific interfaces. This allows you to create blocks with custom logic and presentation.
• Hooks: Utilize hooks such as hook_block_info() (in earlier versions) or implement block plugins to define new blocks, alter existing ones, or modify their output.
• Integration with Other APIs: Blocks can interact with other systems like Views, Forms, Menus and third-party integrations to deliver dynamic content.

The Block API empowers you to extend functionality beyond the default UI, enabling the creation of highly customized, context-aware blocks.

Conclusion

The Block module is a fundamental tool in Drupal, providing a versatile and extensible system for managing content placement across your site. Whether you are a site administrator looking to quickly configure block placements or a developer creating custom block functionality via the Block API, this module is designed to meet your needs. With careful planning, proper configuration, and adherence to best practices, you can create a dynamic and well-organized Drupal site that enhances both performance and user experience.