Add support for an Inputfield 'detail' property, similar to existing 'notes' property, but appears below it and in muted text.

wire/core/Fields.php

@@ -1047,5 +1047,29 @@ class Fields extends WireSaveableItems {
 	 */
 	public function ___changeTypeReady(Saveable $item, Fieldtype $fromType, Fieldtype $toType) { }
 
+	/**
+	 * Get Fieldtypes compatible (for type change) with given Field
+	 * 
+	 * #pw-internal
+	 *
+	 * @param Field $field
+	 * @return array Array of Fieldtype objects indexed by class name
+	 * @since 3.0.140
+	 *
+	 */
+	public function getCompatibleFieldtypes(Field $field) {
+		$fieldtype = $field->type;
+		if($fieldtype) {
+			// ask fieldtype what is compatible
+			$fieldtypes = $fieldtype->getCompatibleFieldtypes($field);
+			// ensure original is present
+			$fieldtypes->prepend($fieldtype);
+		} else {
+			// allow all
+			$fieldtypes = $this->wire('fieldtypes');
+		}
+		return $fieldtypes;
+	}
+
 }
 

wire/core/Fieldtypes.php

@@ -10,6 +10,7 @@
  *
  *
  */
+
 class Fieldtypes extends WireArray {
 
 	/**
@@ -19,12 +20,21 @@ class Fieldtypes extends WireArray {
 	protected $preloaded = false;
 
 	/**
-	 * Construct this Fieldtypes object and load all Fieldtype modules 
+	 * Is this the $fieldtypes API var?
+	 * 
+	 * @var bool
+	 * 
+	 */
+	protected $isAPI = false;
+
+	/**
+	 * Construct the $fieldtypes API var (load all Fieldtype modules into it)
 	 *
  	 */
 	public function init() {
-		foreach($this->wire('modules') as $module) {
+		$this->isAPI = true;
-			if(strpos($module->className(), 'Fieldtype') === 0) {
+		foreach($this->wire('modules') as $name => $module) {
+			if(strpos($name, 'Fieldtype') === 0) {
 				// if($module instanceof ModulePlaceholder) $module = $this->wire('modules')->get($module->className());
 				$this->add($module); 
 			}
@@ -37,7 +47,7 @@ class Fieldtypes extends WireArray {
 	 */
 	protected function preload() {
 		if($this->preloaded) return;
-		$debug = $this->wire('config')->debug; 
+		$debug = $this->isAPI && $this->wire('config')->debug; 
 		if($debug) Debug::timer('Fieldtypes.preload'); 
 		foreach($this->data as $key => $module) {
 			if($module instanceof ModulePlaceholder) {
@@ -57,11 +67,13 @@ class Fieldtypes extends WireArray {
 	 *
 	 */
 	public function isValidItem($item) {
-		return $item instanceof Fieldtype || $item instanceof ModulePlaceholder; 
+		if($item instanceof Fieldtype) return true;
+		if($item instanceof ModulePlaceholder && strpos($item->className(), 'Fieldtype') === 0) return true;
+		return false;
 	}
 
 	/**
-	 * Per the WireArray interface, keys must be strings (field names)
+	 * Per the WireArray interface, keys must be strings (fieldtype class names)
 	 * 
 	 * @param string|int $key
 	 * @return bool
@@ -123,7 +135,7 @@ class Fieldtypes extends WireArray {
 
 		if($fieldtype instanceof ModulePlaceholder) {
 			$fieldtype = $this->wire('modules')->get($fieldtype->className()); 			
-			$this->set($key, $fieldtype); 
+			if($fieldtype) $this->set($key, $fieldtype); 
 		}
 
 		return $fieldtype; 

wire/core/Inputfield.php

@@ -54,6 +54,7 @@
  * @property string $label Primary label text that appears above the input. #pw-group-labels
  * @property string $description Optional description that appears under label to provide more detailed information. #pw-group-labels
  * @property string $notes Optional notes that appear under input area to provide additional notes. #pw-group-labels
+ * @property string $detail Optional text details that appear under notes. @since 3.0.140 #pw-group-labels
  * @property string $icon Optional font-awesome icon name to accompany label (excluding the "fa-") part). #pw-group-labels
  * @property string $requiredLabel Optional custom label to display when missing required value. @since 3.0.98 #pw-group-labels 
  * @property string $head Optional text that appears below label but above description (only used by some Inputfields). #pw-internal
@@ -345,6 +346,7 @@ abstract class Inputfield extends WireData implements Module {
 		$this->set('description', ''); // descriptive copy, below label
 		$this->set('icon', ''); // optional icon name to accompany label
 		$this->set('notes', ''); // highlighted descriptive copy, below output of input field
+		$this->set('detail', ''); // text details that appear below notes
 		$this->set('head', ''); // below label, above description
 		$this->set('required', 0); // set to 1 to make value required for this field
 		$this->set('requiredIf', ''); // optional conditions to make it required
@@ -357,8 +359,8 @@ abstract class Inputfield extends WireData implements Module {
 		$this->set('contentClass', ''); // optional class to apply to InputfieldContent wrapper
 		$this->set('textFormat', self::textFormatBasic); // format applied to description and notes
 		$this->set('renderValueFlags', 0); // see renderValue* constants, applicable to renderValue mode only
-		$this->set('prependMarkup', '');
+		$this->set('prependMarkup', ''); // markup to prepend to Inputfield output
-		$this->set('appendMarkup', '');
+		$this->set('appendMarkup', ''); // markup to append to Inputfield output
 
 		// default ID attribute if no 'id' attribute set
 		$this->defaultID = $this->className() . self::$numInstances; 

wire/core/InputfieldWrapper.php

@@ -52,6 +52,7 @@ class InputfieldWrapper extends Inputfield implements \Countable, \IteratorAggre
 		'item_description' => "<p class='description'>{out}</p>", 
 		'item_head' => "<h2>{out}</h2>", 
 		'item_notes' => "<p class='notes'>{out}</p>",
+		'item_detail' => "<p class='detail'>{out}</p>", 
 		'item_icon' => "<i class='fa fa-fw fa-{name}'></i> ",
 		'item_toggle' => "<i class='toggle-icon fa fa-fw fa-angle-down' data-to='fa-angle-down fa-angle-right'></i>", 
 		// ALSO: 
@@ -497,8 +498,9 @@ class InputfieldWrapper extends Inputfield implements \Countable, \IteratorAggre
 				}
 			} else $errors = array();
 		
-			foreach(array('error', 'description', 'head', 'notes') as $property) {
+			foreach(array('error', 'description', 'head', 'notes', 'detail') as $property) {
 				$text = $property == 'error' ? $errorsOut : $inputfield->getSetting($property); 
+				if($property === 'detail' && !is_string($text)) continue; // may not be necessary
 				if(!empty($text) && !$quietMode) {
 					if($entityEncodeText) {
 						$text = $inputfield->entityEncode($text, true);
@@ -514,7 +516,7 @@ class InputfieldWrapper extends Inputfield implements \Countable, \IteratorAggre
 					$markup['item_content'] = str_replace($_property, $text, $markup['item_content']);
 				} else if(strpos($markup['item_label'], $_property) !== false) {
 					$markup['item_label'] = str_replace($_property, $text, $markup['item_label']);
-				} else if($text && $property == 'notes') {
+				} else if($text && ($property == 'notes' || $property == 'detail')) {
 					$ffOut .= $text;
 				} else if($text) {
 					$ffOut = $text . $ffOut;