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/Drupal 8

class MachineName

Provides a machine name render element.

Provides a form element to enter a machine name, which is validated to ensure that the name is unique and does not contain disallowed characters.

The element may be automatically populated via JavaScript when used in conjunction with a separate "source" form element (typically specifying the human-readable name). As the user types text into the source element, the JavaScript converts all values to lower case, replaces any remaining disallowed characters with a replacement, and populates the associated machine name form element.

Properties:

  • #machine_name: An associative array containing:
    • exists: A callable to invoke for checking whether a submitted machine name value already exists. The arguments passed to the callback will be:
      • The submitted value.
      • The element array.
      • The form state object.

      In most cases, an existing API or menu argument loader function can be re-used. The callback is only invoked if the submitted value differs from the element's #default_value.

    • source: (optional) The #array_parents of the form element containing the human-readable name (i.e., as contained in the $form structure) to use as source for the machine name. Defaults to array('label').
    • label: (optional) Text to display as label for the machine name value after the human-readable name form element. Defaults to t('Machine name').
    • replace_pattern: (optional) A regular expression (without delimiters) matching disallowed characters in the machine name. Defaults to '[^a-z0-9_]+'.
    • replace: (optional) A character to replace disallowed characters in the machine name via JavaScript. Defaults to '_' (underscore). When using a different character, 'replace_pattern' needs to be set accordingly.
    • error: (optional) A custom form error message string to show, if the machine name contains disallowed characters.
    • standalone: (optional) Whether the live preview should stay in its own form element rather than in the suffix of the source element. Defaults to FALSE.
  • #maxlength: (optional) Maximum allowed length of the machine name. Defaults to 64.
  • #disabled: (optional) Should be set to TRUE if an existing machine name must not be changed after initial creation.

Usage example:

$form['id'] = array(
  '#type' => 'machine_name',
  '#default_value' => $this->entity->id(),
  '#disabled' => !$this->entity->isNew(),
  '#maxlength' => 64,
  '#description' => $this->t('A unique name for this item. It must only contain lowercase letters, numbers, and underscores.'),
  '#machine_name' => array(
    'exists' => array($this, 'exists'),
  ),
);

Plugin annotation

@FormElement("machine_name")

Hierarchy

See also

\Drupal\Core\Render\Element\Textfield

File

core/lib/Drupal/Core/Render/Element/MachineName.php, line 71

Namespace

Drupal\Core\Render\Element

Members

Name Modifiers Type Description
DependencySerializationTrait::$_serviceIds protected property An array of service IDs keyed by property name used for serialization.
DependencySerializationTrait::__sleep public function
DependencySerializationTrait::__wakeup public function
FormElement::processAutocomplete public static function Adds autocomplete functionality to elements.
FormElement::processPattern public static function #process callback for #pattern form element property.
FormElement::validatePattern public static function #element_validate callback for #pattern form element property.
MachineName::getInfo public function Returns the element properties for this element. Overrides Textfield::getInfo
MachineName::processMachineName public static function Processes a machine-readable name form element.
MachineName::validateMachineName public static function Form element validation handler for machine_name elements.
MachineName::valueCallback public static function Determines how user input is mapped to an element's #value property. Overrides Textfield::valueCallback
PluginBase::$configuration protected property Configuration information passed into the plugin.
PluginBase::$pluginDefinition protected property The plugin implementation definition.
PluginBase::$pluginId protected property The plugin_id.
PluginBase::DERIVATIVE_SEPARATOR constant A string which is used to separate base plugin IDs from the derivative ID.
PluginBase::getBaseId public function Gets the base_plugin_id of the plugin instance. Overrides DerivativeInspectionInterface::getBaseId
PluginBase::getDerivativeId public function Gets the derivative_id of the plugin instance. Overrides DerivativeInspectionInterface::getDerivativeId
PluginBase::getPluginDefinition public function Gets the definition of the plugin implementation. Overrides PluginInspectionInterface::getPluginDefinition
PluginBase::getPluginId public function Gets the plugin_id of the plugin instance. Overrides PluginInspectionInterface::getPluginId
PluginBase::__construct public function Constructs a Drupal\Component\Plugin\PluginBase object.
RenderElement::preRenderAjaxForm public static function Adds Ajax information about an element to communicate with JavaScript.
RenderElement::preRenderGroup public static function Adds members of this group as actual elements for rendering.
RenderElement::processAjaxForm public static function Form element processing handler for the #ajax form property.
RenderElement::processGroup public static function Arranges elements into groups.
RenderElement::setAttributes public static function Sets a form element's class attribute. Overrides ElementInterface::setAttributes
StringTranslationTrait::$stringTranslation protected property The string translation service.
StringTranslationTrait::formatPlural protected function Formats a string containing a count of items.
StringTranslationTrait::getNumberOfPlurals protected function Returns the number of plurals supported by a given language.
StringTranslationTrait::getStringTranslation protected function Gets the string translation service.
StringTranslationTrait::setStringTranslation public function Sets the string translation service to use.
StringTranslationTrait::t protected function Translates a string to the current language or to a given language.
Textfield::preRenderTextfield public static function Prepares a #type 'textfield' render element for input.html.twig.

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Licensed under the GNU General Public License, version 2 and later.
Drupal is a registered trademark of Dries Buytaert.
https://api.drupal.org/api/drupal/core!lib!Drupal!Core!Render!Element!MachineName.php/class/MachineName/8.1.x