Creating a Custom Text Format Filter Plugin in Drupal: A Beginner’s Tutorial with Code Examples

What is Text Format Filter plugin in Drupal?

Text Format Filter Plugins in Drupal are like editing tools that allow you to change the content of text fields on your website. These fields could be things like the main body of a blog post or a user’s comment on your site.

These plugins let you apply certain formatting or processing to the text people enter on your site. For example, you could limit the types of HTML tags users can enter or automatically turn URLs into clickable links. By enabling and configuring these plugins, you can ensure that your site’s content looks great and is easy to read.

Another advantage of using Text Format Filter Plugins is that they help keep your site safe from security risks. For example, you can use a filter to remove potentially harmful scripts or HTML tags that someone might try entering into a text field.

Overall, these plugins give you a lot of control over the content on your site, making it more engaging and useful for your visitors.

How to create Text filter plugin in Drupal?

1. Create a custom module: Create a custom module named “ttn_custom_module” in your Drupal 10 site.
2. Define the plugin: Create a new PHP file inside your custom module to define the text format filter plugin. The file should be located at /modules/custom/ttn_custom_module/src/Plugin/Filter/TtnFilterPlugin.php.
3. Define the plugin class: Inside the TtnFilterPlugin.php file, define the plugin class by extending the FilterBase class. The class name should be TtnFilterPlugin.
4. Here’s an example of a basic TtnFilterPlugin class:

namespace Drupal\ttn_custom_module\Plugin\Filter;

use Drupal\filter\FilterProcessResult;
use Drupal\filter\Plugin\FilterBase;

/**
* Provides a text format filter that does something.
*
* @Filter(
* id = "ttn_filter_plugin",
* title = @Translation("TTN Filter Plugin"),
* type = Drupal\filter\Plugin\FilterInterface::TYPE_MARKUP_LANGUAGE,
* weight = 0
* )
*/
class TtnFilterPlugin extends FilterBase {

/**
* {@inheritdoc}
*/
public function process($text, $langcode) {
// Modify the text here.
$result = new FilterProcessResult($text);
return $result;
}

}

Now follow the following steps:

1. Implement the process() method: Inside the TtnFilterPlugin class, implement the process() method. This method takes the input text and modifies it according to your plugin’s functionality. The method must return an instance of FilterProcessResult with the modified text.
2. Define the plugin metadata: Above the TtnFilterPlugin class, define the plugin metadata using the @Filter annotation. This metadata includes the plugin ID, title, type, and weight.
3. Enable the plugin: Once you have created the plugin, enable it in your Drupal 10 site by going to the Extend page and selecting the checkbox next to your module’s name.

That’s it! You have created a Drupal text format filter plugin named “ttn_filter_plugin” inside the “ttn_custom_module” module.

If you still have any questions, leave a comment and join the discussion.