bootstrap_components_toolkit-1.0.0/src/BoostrapComponentsToolkitTwigExtension.php

<?php

namespace Drupal\bootstrap_components_toolkit;

use Drupal\Core\Template\Attribute;
use Twig\Extension\AbstractExtension;
use Twig\TwigFunction;

/**
 * Twig extension.
 */
class BoostrapComponentsToolkitTwigExtension extends AbstractExtension {

  /**
   * {@inheritdoc}
   */
  public function getFunctions() {
    return [
      new TwigFunction('safe_create_attribute', [$this, 'safeCreateAttribute']),
      new TwigFunction('get_contrast_color', [$this, 'getContrastColor']),
    ];
  }

  /**
   * Detects if the attributes are present and generate or populate them.
   *
   * This works with a higher lever of uncertainty than core's create_attribute
   * twig function, as it can accept three different scenarios: no attributes,
   * attributes as an array, attributes already as an Attributes object. In
   * any case, it will return a valid attributes object.
   *
   * @param mixed $attributes
   *   An Attributes object or array.
   *
   * @return \Drupal\Core\Template\Attribute
   *   An Attributes object.
   */
  public function safeCreateAttribute($attributes): Attribute {
    if ($attributes instanceof Attribute) {
      return $attributes;
    }
    elseif (is_array($attributes)) {
      return new Attribute($attributes);
    }
    else {
      return new Attribute();
    }
  }

  /**
   * Tries to find the contrast color value for a given color keyword.
   *
   * This works in conjuction with the theme settings that allow the user to
   * define, per theme, how is each Bootstrap color keyword supposed to
   * contrast against a text.
   *
   * @param string $color_name
   *   An Bootstrap color keyword.
   *
   * @return string|null
   *   Either 'dark', 'light' or NULL if the color has no match.
   */
  public function getContrastColor(string $color_name): ?string {
    $result = NULL;

    // Try to find the contrast color on the theme settings.
    $contrast_color = theme_get_setting("contrast-$color_name");

    if (!empty($contrast_color)) {
      $result = $contrast_color;
    }

    return $result;
  }

}