Generating Code with a Command

Generating Code with a Command

To generate code from a Command, there are three steps:

1. Create a Twig template for the code you want to generate.
2. Create and register a custom Generator service for rendering the Twig template.
3. Inject the custom Generator service into your Command.

## Creating a Twig Template for the Generated Code

All Twig templates should be placed inside a templates subdirectory of your module or extension. For example:

templates/module/info.yml.twig

name: {{ module }}
type: {{ type }}
description: {{ description }}
core: {{ core }}
package: {{ package }}
{% if dependencies %}
dependencies:
{% for dependency in dependencies %}
  - {{ dependency }}
{% endfor %}
{% endif %}

## Creating a Custom Generator Service

To create a custom Generator service, first create a class that extends from Drupal\Console\Core\Generator\Generator. For example:

src/Generator/ModuleGenerator

namespace Drupal\your_extension\Generator;

use Drupal\Console\Core\Generator\Generator;

class ModuleGenerator extends Generator
{
  ...
}

Use the renderFile() method inherited from the Generator class to render your Twig template.

public function generate($module, $machineName, $output_dir, $description, $core, $package, $dependencies) {

  $parameters = [
    'module' => $module,
    'core' => $core,
    'description' => $description,
    'package' => $package,
    'dependencies' => $dependencies,
  ];

  $this->renderFile(
    'module/info.yml.twig',
    $output_dir.'/'.$machineName.'.info.yml',
    $parameters
  );

}

Finally, register your Generator class as a custom service in console.services.yml.

services:
  your_extension.module_generator:
    class: Drupal\your_extension\Generator\ModuleGenerator
    tags:
      - { name: drupal.generator }

Be sure to include the drupal.generator tag so that the Twig renderer is properly initialized.

## Injecting Your Custom Generator Into Your Command

In console.services.yml, add your custom Generator service as an argument for your custom Command.

services:
  your_extension.generate_module:
    class: Drupal\your_extension\Command\Generate\ModuleCommand
    arguments: ['@your_extension.module_generator']
    tags:
       - { name: drupal.command }

And add your custom Generator to the constructor parameters for your Command class:

use Drupal\your_extension\Generator\ModuleGenerator;

class ModuleCommand extends Command
{
  /**
   * ModuleCommand constructor.
   *
   * @param \Drupal\your_extension\Generator\ModuleGenerator $generator
   */
  public function __construct(ModuleGenerator $generator) {
    $this->generator = $generator;
    parent::__construct();
  }
   
  ...
}

You can now call your Generator from the execute() method in your Command to output rendered code files:

protected function execute(InputInterface $input, OutputInterface $output) {
  
  ...
  
  $this->generator->generate(
    $module,
    $machineName,
    $modulePath,
    $description,
    $core,
    $package,
    $dependencies
  );
  
}