Merge branch 'F7729SELECTAsDatalist' into 'master'

F7729 select as datalist

See merge request !121

extension/Documentation/Manual.rst

@@ -3458,6 +3458,8 @@ Type: select
   * *emptyItemAtEnd*: Existence of this item inserts an empty entry at the end of the selectlist.
   * *emptyHide*: Existence of this item hides the empty entry. This is useful for e.g. Enums, which have an empty
     entry and the empty value should not be an option to be selected.
+  * *datalist*: Similar to 'typeAhead'. Enables the user to select a predefined option (sql1, itemList) or supply any
+     free text. Attention: Safari (and some other) browsers do not support this fully - https://caniuse.com/#search=datalist.
 
 .. _`subrecord-option`:
 

extension/Source/core/AbstractBuildForm.php

@@ -2448,9 +2448,17 @@ abstract class AbstractBuildForm {
 
         $formElement = HelperFormElement::prepareExtraButton($formElement, false);
         $attribute .= $this->getAttributeFeMode($formElement[FE_MODE]);
-        $html = '<select ' . $attribute . '>' . $option . '</select>';
+        if (isset($formElement["datalist"])) {
+            if ($formElement[FE_DYNAMIC_UPDATE] === 'yes') {
+                throw new UserFormException("Datalist funktionert nicht mit dynamic update", ERROR_NOT_IMPLEMENTED);
+            }
+            $datalistId = $formElement[FE_HTML_ID] . '-datalist';
+            $html = '<input ' . Support::doAttribute('list', $datalistId) . $attribute . '><datalist '
+                . Support::doAttribute('id', $datalistId) . '>' . $option . '</datalist>';
+        } else {
+            $html = '<select ' . $attribute . '>' . $option . '</select>';
+        }
         $html = $html . $this->getHelpBlock() . $formElement[FE_TMP_EXTRA_BUTTON_HTML];
-
         return $html . $formElement[FE_INPUT_EXTRA_BUTTON_INFO];
     }