class ColorBackgroudFormatter
Same name in other branches
- 8.x-1.x field_example/src/Plugin/Field/FieldFormatter/ColorBackgroudFormatter.php \Drupal\field_example\Plugin\Field\FieldFormatter\ColorBackgroudFormatter
- 4.0.x modules/field_example/src/Plugin/Field/FieldFormatter/ColorBackgroudFormatter.php \Drupal\field_example\Plugin\Field\FieldFormatter\ColorBackgroudFormatter
Plugin implementation of the 'field_example_color_background' formatter.
This example demonstrates how a field formatter plugin can provide configuration options to the user and then alter the output based on their choices. We'll add a toggle, that defaults to on, for a feature that attempts to automatically adjust the foreground color of the text to either black or white depending on the lightness of the background color.
Plugin annotation
@FieldFormatter(
id = "field_example_color_background",
label = @Translation("Change the background of the output text"),
field_types = {
"field_example_rgb"
}
)
Hierarchy
- class \Drupal\Component\Plugin\PluginBase implements \Drupal\Component\Plugin\PluginInspectionInterface, \Drupal\Component\Plugin\DerivativeInspectionInterface
- class \Drupal\Core\Plugin\PluginBase extends \Drupal\Component\Plugin\PluginBase uses \Drupal\Core\StringTranslation\StringTranslationTrait, \Drupal\Core\DependencyInjection\DependencySerializationTrait, \Drupal\Core\Messenger\MessengerTrait
- class \Drupal\Core\Field\PluginSettingsBase extends \Drupal\Core\Plugin\PluginBase implements \Drupal\Core\Field\PluginSettingsInterface, \Drupal\Component\Plugin\DependentPluginInterface
- class \Drupal\Core\Field\FormatterBase extends \Drupal\Core\Field\PluginSettingsBase implements \Drupal\Core\Field\FormatterInterface, \Drupal\Core\Plugin\ContainerFactoryPluginInterface
- class \Drupal\field_example\Plugin\Field\FieldFormatter\ColorBackgroudFormatter extends \Drupal\Core\Field\FormatterBase
- class \Drupal\Core\Field\FormatterBase extends \Drupal\Core\Field\PluginSettingsBase implements \Drupal\Core\Field\FormatterInterface, \Drupal\Core\Plugin\ContainerFactoryPluginInterface
- class \Drupal\Core\Field\PluginSettingsBase extends \Drupal\Core\Plugin\PluginBase implements \Drupal\Core\Field\PluginSettingsInterface, \Drupal\Component\Plugin\DependentPluginInterface
- class \Drupal\Core\Plugin\PluginBase extends \Drupal\Component\Plugin\PluginBase uses \Drupal\Core\StringTranslation\StringTranslationTrait, \Drupal\Core\DependencyInjection\DependencySerializationTrait, \Drupal\Core\Messenger\MessengerTrait
Expanded class hierarchy of ColorBackgroudFormatter
File
-
modules/
field_example/ src/ Plugin/ Field/ FieldFormatter/ ColorBackgroudFormatter.php, line 26
Namespace
Drupal\field_example\Plugin\Field\FieldFormatterView source
class ColorBackgroudFormatter extends FormatterBase {
/**
* {@inheritdoc}
*/
public function viewElements(FieldItemListInterface $items, $langcode) {
$elements = [];
foreach ($items as $delta => $item) {
// Set the value of the CSS color property depending on user provided
// configuration. Individual configuration items can be accessed with
// $this->getSetting('key') where 'key' is the same as the key in the
// form array from settingsForm() and what's defined in the configuration
// schema.
$text_color = 'inherit';
if ($this->getSetting('adjust_text_color')) {
$text_color = $this->lightness($item->value) < 50 ? 'white' : 'black';
}
$elements[$delta] = [
'#type' => 'html_tag',
'#tag' => 'p',
'#value' => $this->t('The content area color has been changed to @code', [
'@code' => $item->value,
]),
'#attributes' => [
'style' => 'background-color: ' . $item->value . '; color: ' . $text_color,
],
];
}
return $elements;
}
/**
* {@inheritdoc}
*
* Set the default values for the formatter's configuration.
*/
public static function defaultSettings() {
// The keys of this array should match the form element names in
// settingsForm(), and the schema defined in
// config/schema/field_example.schema.yml.
return [
'adjust_text_color' => TRUE,
] + parent::defaultSettings();
}
/**
* {@inheritdoc}
*
* Define the Form API widgets a user should see when configuring the
* formatter. These are displayed when a user clicks the gear icon in the row
* for a formatter on the manage display page.
*
* The field_ui module takes care of handling submitted form values.
*/
public function settingsForm(array $form, FormStateInterface $form_state) {
// Create a new array with one or more form elements. $form is available for
// context but you should not add your elements to it directly.
$elements = [];
// The keys of the array, 'adjust_text_color' in this case, should match
// what is defined in ::defaultSettings(), and the field_example.schema.yml
// schema. The values collected by the form will be automatically stored
// as part of the field instance configuration so you do not need to
// implement form submission processing.
$elements['adjust_text_color'] = [
'#type' => 'checkbox',
// The current configuration for this setting for the field instance can
// be accessed via $this->getSetting().
'#default_value' => $this->getSetting('adjust_text_color'),
'#title' => $this->t('Adjust foreground text color'),
'#description' => $this->t('Switch the foreground color between black and white depending on lightness of the background color.'),
];
return $elements;
}
/**
* {@inheritdoc}
*/
public function settingsSummary() {
// This optional summary text is displayed on the manage displayed in place
// of the formatter configuration form when the form is closed. You'll
// usually see it in the list of fields on the manage display page where
// this formatter is used.
$state = $this->getSetting('adjust_text_color') ? $this->t('yes') : $this->t('no');
$summary[] = $this->t('Adjust text color: @state', [
'@state' => $state,
]);
return $summary;
}
/**
* Determine lightness of a color.
*
* This might not be the best way to determine if the contrast between the
* foreground and background colors is legible. But it'll work well enough for
* this demonstration.
*
* Logic from https://stackoverflow.com/a/12228730/8616016.
*
* @param string $color
* A color in hex format, leading '#' is optional.
*
* @return float
* Percentage of lightness of the provided color.
*/
protected function lightness(string $color) {
$hex = ltrim($color, '#');
// Convert the hex string to RGB.
$r = hexdec($hex[0] . $hex[1]);
$g = hexdec($hex[2] . $hex[3]);
$b = hexdec($hex[4] . $hex[5]);
// Calculate the HSL lightness value and return that as a percent.
return (max($r, $g, $b) + min($r, $g, $b)) / 510.0 * 100;
}
}
Members
Title Sort descending | Modifiers | Object type | Summary | Overriden Title | Overrides |
---|---|---|---|---|---|
ColorBackgroudFormatter::defaultSettings | public static | function | Set the default values for the formatter's configuration. | Overrides PluginSettingsBase::defaultSettings | |
ColorBackgroudFormatter::lightness | protected | function | Determine lightness of a color. | ||
ColorBackgroudFormatter::settingsForm | public | function | Define the Form API widgets a user should see when configuring the formatter. These are displayed when a user clicks the gear icon in the row for a formatter on the manage display page. |
Overrides FormatterBase::settingsForm | |
ColorBackgroudFormatter::settingsSummary | public | function | Returns a short summary for the current formatter settings. | Overrides FormatterBase::settingsSummary | |
ColorBackgroudFormatter::viewElements | public | function | Builds a renderable array for a field value. | Overrides FormatterInterface::viewElements | |
FormatterBase::$fieldDefinition | protected | property | The field definition. | ||
FormatterBase::$label | protected | property | The label display setting. | ||
FormatterBase::$settings | protected | property | The formatter settings. | Overrides PluginSettingsBase::$settings | |
FormatterBase::$viewMode | protected | property | The view mode. | ||
FormatterBase::create | public static | function | Creates an instance of the plugin. | Overrides ContainerFactoryPluginInterface::create | 13 |
FormatterBase::getFieldSetting | protected | function | Returns the value of a field setting. | ||
FormatterBase::getFieldSettings | protected | function | Returns the array of field settings. | ||
FormatterBase::isApplicable | public static | function | Returns if the formatter can be used for the provided field. | Overrides FormatterInterface::isApplicable | 14 |
FormatterBase::prepareView | public | function | Allows formatters to load information for field values being displayed. | Overrides FormatterInterface::prepareView | 2 |
FormatterBase::view | public | function | Builds a renderable array for a fully themed field. | Overrides FormatterInterface::view | 1 |
FormatterBase::__construct | public | function | Constructs a FormatterBase object. | 13 | |
PluginInspectionInterface::getPluginDefinition | public | function | Gets the definition of the plugin implementation. | 6 | |
PluginInspectionInterface::getPluginId | public | function | Gets the plugin_id of the plugin instance. | 2 | |
PluginSettingsBase::$defaultSettingsMerged | protected | property | Whether default settings have been merged into the current $settings. | ||
PluginSettingsBase::$thirdPartySettings | protected | property | The plugin settings injected by third party modules. | ||
PluginSettingsBase::calculateDependencies | public | function | Calculates dependencies for the configured plugin. | Overrides DependentPluginInterface::calculateDependencies | 6 |
PluginSettingsBase::getSetting | public | function | Returns the value of a setting, or its default value if absent. | Overrides PluginSettingsInterface::getSetting | |
PluginSettingsBase::getSettings | public | function | Returns the array of settings, including defaults for missing settings. | Overrides PluginSettingsInterface::getSettings | |
PluginSettingsBase::getThirdPartyProviders | public | function | Gets the list of third parties that store information. | Overrides ThirdPartySettingsInterface::getThirdPartyProviders | |
PluginSettingsBase::getThirdPartySetting | public | function | Gets the value of a third-party setting. | Overrides ThirdPartySettingsInterface::getThirdPartySetting | |
PluginSettingsBase::getThirdPartySettings | public | function | Gets all third-party settings of a given module. | Overrides ThirdPartySettingsInterface::getThirdPartySettings | |
PluginSettingsBase::mergeDefaults | protected | function | Merges default settings values into $settings. | ||
PluginSettingsBase::onDependencyRemoval | public | function | Informs the plugin that some configuration it depends on will be deleted. | Overrides PluginSettingsInterface::onDependencyRemoval | 3 |
PluginSettingsBase::setSetting | public | function | Sets the value of a setting for the plugin. | Overrides PluginSettingsInterface::setSetting | |
PluginSettingsBase::setSettings | public | function | Sets the settings for the plugin. | Overrides PluginSettingsInterface::setSettings | |
PluginSettingsBase::setThirdPartySetting | public | function | Sets the value of a third-party setting. | Overrides ThirdPartySettingsInterface::setThirdPartySetting | |
PluginSettingsBase::unsetThirdPartySetting | public | function | Unsets a third-party setting. | Overrides ThirdPartySettingsInterface::unsetThirdPartySetting |