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

• class \Drupal\Component\Plugin\PluginBase implements DerivativeInspectionInterface, PluginInspectionInterface
  • class \Drupal\Core\Plugin\PluginBase uses DependencySerializationTrait, StringTranslationTrait
    • class \Drupal\Core\Render\Element\RenderElement implements ElementInterface
      • class \Drupal\Core\Render\Element\FormElement implements FormElementInterface
        • class \Drupal\Core\Render\Element\Textfield
          • class \Drupal\Core\Render\Element\MachineName

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.