summaryrefslogtreecommitdiffstatshomepage
path: root/core/lib/Drupal/Core/Template/AttributeBoolean.php
blob: cc948202da7feeff3e0ddc355d32bb10ec746cb9 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
<?php

namespace Drupal\Core\Template;

use Drupal\Component\Utility\Html;

/**
 * A class that defines a type of boolean HTML attribute.
 *
 * Boolean HTML attributes are not attributes with values of TRUE/FALSE.
 * They are attributes that if they exist in the tag, they are TRUE.
 * Examples include selected, disabled, checked, readonly.
 *
 * To set a boolean attribute on the Attribute class, set it to TRUE.
 * @code
 *  $attributes = new Attribute();
 *  $attributes['disabled'] = TRUE;
 *  echo '<select' . $attributes . '/>';
 *  // produces <select disabled>;
 *  $attributes['disabled'] = FALSE;
 *  echo '<select' . $attributes . '/>';
 *  // produces <select>;
 * @endcode
 *
 * @see \Drupal\Core\Template\Attribute
 */
class AttributeBoolean extends AttributeValueBase {

  /**
   * {@inheritdoc}
   */
  public function render() {
    return $this->__toString();
  }

  /**
   * Implements the magic __toString() method.
   */
  public function __toString() {
    return $this->value === FALSE ? '' : Html::escape($this->name);
  }

}