elements.txt

$ drush @d8 ev "var_dump(\Drupal::service('plugin.manager.element_info')->getDefinitions());"

array(65) {
  ["contextual_links"]=>
  array(3) {
    ["id"]=>
    string(16) "contextual_links"
    ["class"]=>
    string(41) "Drupal\contextual\Element\ContextualLinks"
    ["provider"]=>
    string(10) "contextual"
  }
  ["contextual_links_placeholder"]=>
  array(3) {
    ["id"]=>
    string(28) "contextual_links_placeholder"
    ["class"]=>
    string(52) "Drupal\contextual\Element\ContextualLinksPlaceholder"
    ["provider"]=>
    string(10) "contextual"
  }
  ["field_ui_table"]=>
  array(3) {
    ["id"]=>
    string(14) "field_ui_table"
    ["class"]=>
    string(36) "Drupal\field_ui\Element\FieldUiTable"
    ["provider"]=>
    string(8) "field_ui"
  }
  ["managed_file"]=>
  array(3) {
    ["id"]=>
    string(12) "managed_file"
    ["class"]=>
    string(31) "Drupal\file\Element\ManagedFile"
    ["provider"]=>
    string(4) "file"
  }
  ["processed_text"]=>
  array(3) {
    ["id"]=>
    string(14) "processed_text"
    ["class"]=>
    string(35) "Drupal\filter\Element\ProcessedText"
    ["provider"]=>
    string(6) "filter"
  }
  ["text_format"]=>
  array(3) {
    ["id"]=>
    string(11) "text_format"
    ["class"]=>
    string(32) "Drupal\filter\Element\TextFormat"
    ["provider"]=>
    string(6) "filter"
  }
  ["language_configuration"]=>
  array(3) {
    ["id"]=>
    string(22) "language_configuration"
    ["class"]=>
    string(45) "Drupal\language\Element\LanguageConfiguration"
    ["provider"]=>
    string(8) "language"
  }
  ["toolbar_item"]=>
  array(3) {
    ["id"]=>
    string(12) "toolbar_item"
    ["class"]=>
    string(34) "Drupal\toolbar\Element\ToolbarItem"
    ["provider"]=>
    string(7) "toolbar"
  }
  ["toolbar"]=>
  array(3) {
    ["id"]=>
    string(7) "toolbar"
    ["class"]=>
    string(30) "Drupal\toolbar\Element\Toolbar"
    ["provider"]=>
    string(7) "toolbar"
  }
  ["view"]=>
  array(3) {
    ["id"]=>
    string(4) "view"
    ["class"]=>
    string(25) "Drupal\views\Element\View"
    ["provider"]=>
    string(5) "views"
  }
  ["password_confirm"]=>
  array(3) {
    ["id"]=>
    string(16) "password_confirm"
    ["class"]=>
    string(42) "Drupal\Core\Render\Element\PasswordConfirm"
    ["provider"]=>
    string(4) "core"
  }
  ["submit"]=>
  array(3) {
    ["id"]=>
    string(6) "submit"
    ["class"]=>
    string(33) "Drupal\Core\Render\Element\Submit"
    ["provider"]=>
    string(4) "core"
  }
  ["tableselect"]=>
  array(3) {
    ["id"]=>
    string(11) "tableselect"
    ["class"]=>
    string(38) "Drupal\Core\Render\Element\Tableselect"
    ["provider"]=>
    string(4) "core"
  }
  ["language_select"]=>
  array(3) {
    ["id"]=>
    string(15) "language_select"
    ["class"]=>
    string(41) "Drupal\Core\Render\Element\LanguageSelect"
    ["provider"]=>
    string(4) "core"
  }
  ["radios"]=>
  array(3) {
    ["id"]=>
    string(6) "radios"
    ["class"]=>
    string(33) "Drupal\Core\Render\Element\Radios"
    ["provider"]=>
    string(4) "core"
  }
  ["checkboxes"]=>
  array(3) {
    ["id"]=>
    string(10) "checkboxes"
    ["class"]=>
    string(37) "Drupal\Core\Render\Element\Checkboxes"
    ["provider"]=>
    string(4) "core"
  }
  ["button"]=>
  array(3) {
    ["id"]=>
    string(6) "button"
    ["class"]=>
    string(33) "Drupal\Core\Render\Element\Button"
    ["provider"]=>
    string(4) "core"
  }
  ["url"]=>
  array(3) {
    ["id"]=>
    string(3) "url"
    ["class"]=>
    string(30) "Drupal\Core\Render\Element\Url"
    ["provider"]=>
    string(4) "core"
  }
  ["color"]=>
  array(3) {
    ["id"]=>
    string(5) "color"
    ["class"]=>
    string(32) "Drupal\Core\Render\Element\Color"
    ["provider"]=>
    string(4) "core"
  }
  ["textarea"]=>
  array(3) {
    ["id"]=>
    string(8) "textarea"
    ["class"]=>
    string(35) "Drupal\Core\Render\Element\Textarea"
    ["provider"]=>
    string(4) "core"
  }
  ["actions"]=>
  array(3) {
    ["id"]=>
    string(7) "actions"
    ["class"]=>
    string(34) "Drupal\Core\Render\Element\Actions"
    ["provider"]=>
    string(4) "core"
  }
  ["page_title"]=>
  array(3) {
    ["id"]=>
    string(10) "page_title"
    ["class"]=>
    string(36) "Drupal\Core\Render\Element\PageTitle"
    ["provider"]=>
    string(4) "core"
  }
  ["pager"]=>
  array(3) {
    ["id"]=>
    string(5) "pager"
    ["class"]=>
    string(32) "Drupal\Core\Render\Element\Pager"
    ["provider"]=>
    string(4) "core"
  }
  ["password"]=>
  array(3) {
    ["id"]=>
    string(8) "password"
    ["class"]=>
    string(35) "Drupal\Core\Render\Element\Password"
    ["provider"]=>
    string(4) "core"
  }
  ["search"]=>
  array(3) {
    ["id"]=>
    string(6) "search"
    ["class"]=>
    string(33) "Drupal\Core\Render\Element\Search"
    ["provider"]=>
    string(4) "core"
  }
  ["date"]=>
  array(3) {
    ["id"]=>
    string(4) "date"
    ["class"]=>
    string(31) "Drupal\Core\Render\Element\Date"
    ["provider"]=>
    string(4) "core"
  }
  ["page"]=>
  array(3) {
    ["id"]=>
    string(4) "page"
    ["class"]=>
    string(31) "Drupal\Core\Render\Element\Page"
    ["provider"]=>
    string(4) "core"
  }
  ["details"]=>
  array(3) {
    ["id"]=>
    string(7) "details"
    ["class"]=>
    string(34) "Drupal\Core\Render\Element\Details"
    ["provider"]=>
    string(4) "core"
  }
  ["system_compact_link"]=>
  array(3) {
    ["id"]=>
    string(19) "system_compact_link"
    ["class"]=>
    string(44) "Drupal\Core\Render\Element\SystemCompactLink"
    ["provider"]=>
    string(4) "core"
  }
  ["tel"]=>
  array(3) {
    ["id"]=>
    string(3) "tel"
    ["class"]=>
    string(30) "Drupal\Core\Render\Element\Tel"
    ["provider"]=>
    string(4) "core"
  }
  ["value"]=>
  array(3) {
    ["id"]=>
    string(5) "value"
    ["class"]=>
    string(32) "Drupal\Core\Render\Element\Value"
    ["provider"]=>
    string(4) "core"
  }
  ["table"]=>
  array(3) {
    ["id"]=>
    string(5) "table"
    ["class"]=>
    string(32) "Drupal\Core\Render\Element\Table"
    ["provider"]=>
    string(4) "core"
  }
  ["dropbutton"]=>
  array(3) {
    ["id"]=>
    string(10) "dropbutton"
    ["class"]=>
    string(37) "Drupal\Core\Render\Element\Dropbutton"
    ["provider"]=>
    string(4) "core"
  }
  ["form"]=>
  array(3) {
    ["id"]=>
    string(4) "form"
    ["class"]=>
    string(31) "Drupal\Core\Render\Element\Form"
    ["provider"]=>
    string(4) "core"
  }
  ["textfield"]=>
  array(3) {
    ["id"]=>
    string(9) "textfield"
    ["class"]=>
    string(36) "Drupal\Core\Render\Element\Textfield"
    ["provider"]=>
    string(4) "core"
  }
  ["range"]=>
  array(3) {
    ["id"]=>
    string(5) "range"
    ["class"]=>
    string(32) "Drupal\Core\Render\Element\Range"
    ["provider"]=>
    string(4) "core"
  }
  ["inline_template"]=>
  array(3) {
    ["id"]=>
    string(15) "inline_template"
    ["class"]=>
    string(41) "Drupal\Core\Render\Element\InlineTemplate"
    ["provider"]=>
    string(4) "core"
  }
  ["file"]=>
  array(3) {
    ["id"]=>
    string(4) "file"
    ["class"]=>
    string(31) "Drupal\Core\Render\Element\File"
    ["provider"]=>
    string(4) "core"
  }
  ["weight"]=>
  array(3) {
    ["id"]=>
    string(6) "weight"
    ["class"]=>
    string(33) "Drupal\Core\Render\Element\Weight"
    ["provider"]=>
    string(4) "core"
  }
  ["path"]=>
  array(3) {
    ["id"]=>
    string(4) "path"
    ["class"]=>
    string(38) "Drupal\Core\Render\Element\PathElement"
    ["provider"]=>
    string(4) "core"
  }
  ["ajax"]=>
  array(3) {
    ["id"]=>
    string(4) "ajax"
    ["class"]=>
    string(31) "Drupal\Core\Render\Element\Ajax"
    ["provider"]=>
    string(4) "core"
  }
  ["number"]=>
  array(3) {
    ["id"]=>
    string(6) "number"
    ["class"]=>
    string(33) "Drupal\Core\Render\Element\Number"
    ["provider"]=>
    string(4) "core"
  }
  ["vertical_tabs"]=>
  array(3) {
    ["id"]=>
    string(13) "vertical_tabs"
    ["class"]=>
    string(39) "Drupal\Core\Render\Element\VerticalTabs"
    ["provider"]=>
    string(4) "core"
  }
  ["link"]=>
  array(3) {
    ["id"]=>
    string(4) "link"
    ["class"]=>
    string(31) "Drupal\Core\Render\Element\Link"
    ["provider"]=>
    string(4) "core"
  }
  ["hidden"]=>
  array(3) {
    ["id"]=>
    string(6) "hidden"
    ["class"]=>
    string(33) "Drupal\Core\Render\Element\Hidden"
    ["provider"]=>
    string(4) "core"
  }
  ["container"]=>
  array(3) {
    ["id"]=>
    string(9) "container"
    ["class"]=>
    string(36) "Drupal\Core\Render\Element\Container"
    ["provider"]=>
    string(4) "core"
  }
  ["fieldgroup"]=>
  array(3) {
    ["id"]=>
    string(10) "fieldgroup"
    ["class"]=>
    string(37) "Drupal\Core\Render\Element\Fieldgroup"
    ["provider"]=>
    string(4) "core"
  }
  ["label"]=>
  array(3) {
    ["id"]=>
    string(5) "label"
    ["class"]=>
    string(32) "Drupal\Core\Render\Element\Label"
    ["provider"]=>
    string(4) "core"
  }
  ["radio"]=>
  array(3) {
    ["id"]=>
    string(5) "radio"
    ["class"]=>
    string(32) "Drupal\Core\Render\Element\Radio"
    ["provider"]=>
    string(4) "core"
  }
  ["fieldset"]=>
  array(3) {
    ["id"]=>
    string(8) "fieldset"
    ["class"]=>
    string(35) "Drupal\Core\Render\Element\Fieldset"
    ["provider"]=>
    string(4) "core"
  }
  ["html"]=>
  array(3) {
    ["id"]=>
    string(4) "html"
    ["class"]=>
    string(31) "Drupal\Core\Render\Element\Html"
    ["provider"]=>
    string(4) "core"
  }
  ["image_button"]=>
  array(3) {
    ["id"]=>
    string(12) "image_button"
    ["class"]=>
    string(38) "Drupal\Core\Render\Element\ImageButton"
    ["provider"]=>
    string(4) "core"
  }
  ["select"]=>
  array(3) {
    ["id"]=>
    string(6) "select"
    ["class"]=>
    string(33) "Drupal\Core\Render\Element\Select"
    ["provider"]=>
    string(4) "core"
  }
  ["checkbox"]=>
  array(3) {
    ["id"]=>
    string(8) "checkbox"
    ["class"]=>
    string(35) "Drupal\Core\Render\Element\Checkbox"
    ["provider"]=>
    string(4) "core"
  }
  ["token"]=>
  array(3) {
    ["id"]=>
    string(5) "token"
    ["class"]=>
    string(32) "Drupal\Core\Render\Element\Token"
    ["provider"]=>
    string(4) "core"
  }
  ["more_link"]=>
  array(3) {
    ["id"]=>
    string(9) "more_link"
    ["class"]=>
    string(35) "Drupal\Core\Render\Element\MoreLink"
    ["provider"]=>
    string(4) "core"
  }
  ["html_tag"]=>
  array(3) {
    ["id"]=>
    string(8) "html_tag"
    ["class"]=>
    string(34) "Drupal\Core\Render\Element\HtmlTag"
    ["provider"]=>
    string(4) "core"
  }
  ["email"]=>
  array(3) {
    ["id"]=>
    string(5) "email"
    ["class"]=>
    string(32) "Drupal\Core\Render\Element\Email"
    ["provider"]=>
    string(4) "core"
  }
  ["operations"]=>
  array(3) {
    ["id"]=>
    string(10) "operations"
    ["class"]=>
    string(37) "Drupal\Core\Render\Element\Operations"
    ["provider"]=>
    string(4) "core"
  }
  ["status_messages"]=>
  array(3) {
    ["id"]=>
    string(15) "status_messages"
    ["class"]=>
    string(41) "Drupal\Core\Render\Element\StatusMessages"
    ["provider"]=>
    string(4) "core"
  }
  ["machine_name"]=>
  array(3) {
    ["id"]=>
    string(12) "machine_name"
    ["class"]=>
    string(38) "Drupal\Core\Render\Element\MachineName"
    ["provider"]=>
    string(4) "core"
  }
  ["item"]=>
  array(3) {
    ["id"]=>
    string(4) "item"
    ["class"]=>
    string(31) "Drupal\Core\Render\Element\Item"
    ["provider"]=>
    string(4) "core"
  }
  ["entity_autocomplete"]=>
  array(3) {
    ["id"]=>
    string(19) "entity_autocomplete"
    ["class"]=>
    string(45) "Drupal\Core\Entity\Element\EntityAutocomplete"
    ["provider"]=>
    string(4) "core"
  }
  ["datetime"]=>
  array(3) {
    ["id"]=>
    string(8) "datetime"
    ["class"]=>
    string(37) "Drupal\Core\Datetime\Element\Datetime"
    ["provider"]=>
    string(4) "core"
  }
  ["datelist"]=>
  array(3) {
    ["id"]=>
    string(8) "datelist"
    ["class"]=>
    string(37) "Drupal\Core\Datetime\Element\Datelist"
    ["provider"]=>
    string(4) "core"
  }
}

$ drush @d8 ev "var_dump(\Drupal::service('plugin.manager.element_info')->getInfo('datelist'));" 
array(13) {
  ["#input"]=>
  bool(true)
  ["#element_validate"]=>
  array(1) {
    [0]=>
    array(2) {
      [0]=>
      string(37) "Drupal\Core\Datetime\Element\Datelist"
      [1]=>
      string(16) "validateDatelist"
    }
  }
  ["#process"]=>
  array(1) {
    [0]=>
    array(2) {
      [0]=>
      string(37) "Drupal\Core\Datetime\Element\Datelist"
      [1]=>
      string(15) "processDatelist"
    }
  }
  ["#theme"]=>
  string(13) "datetime_form"
  ["#theme_wrappers"]=>
  array(1) {
    [0]=>
    string(16) "datetime_wrapper"
  }
  ["#date_part_order"]=>
  array(5) {
    [0]=>
    string(4) "year"
    [1]=>
    string(5) "month"
    [2]=>
    string(3) "day"
    [3]=>
    string(4) "hour"
    [4]=>
    string(6) "minute"
  }
  ["#date_year_range"]=>
  string(9) "1900:2050"
  ["#date_increment"]=>
  int(1)
  ["#date_date_callbacks"]=>
  array(0) {
  }
  ["#date_timezone"]=>
  string(0) ""
  ["#value_callback"]=>
  array(2) {
    [0]=>
    string(37) "Drupal\Core\Datetime\Element\Datelist"
    [1]=>
    string(13) "valueCallback"
  }
  ["#type"]=>
  string(8) "datelist"
  ["#defaults_loaded"]=>
  bool(true)
}