fix: DHCPServer model adjustments

pfSense-pkg-API/files/etc/inc/api/core/Field.inc

@@ -739,7 +739,7 @@ class Field
      * `value` property for this object.
      * @param string|null $internal_value The raw internal config value to convert to a representation value.
      */
-    public function from_internal(string|null $internal_value) {
+    public function from_internal(mixed $internal_value) {
         # Keep null values for non boolean values and representation only values
         if ($this->representation_only or (is_null($internal_value) and $this->type !== "boolean")) {
             # Check if this field has a default, if so, use the default value

pfSense-pkg-API/files/etc/inc/api/core/Model.inc

@@ -152,6 +152,39 @@ class Model {
         return (array_set_path($config, $path, $value, $default));
     }
 
+    /**
+     * Merges changed Model field values into the config. This is similar to `set_config()` but instead of replacing
+     * the entire config path with a set value, it only sets Field's known to this Model. Any fields in the stored
+     * object that are not defined in a Field assigned to this Model will be left unchanged.
+     * @param $path string The Model config path including any Model ID
+     */
+    public function merge_config(string $path) {
+        # Loop through each field known to this Model
+        foreach ($this->get_fields() as $field) {
+            # Determine the field path
+            if ($this->$field->internal_namespace) {
+                $field_path = "$path/{$this->$field->internal_namespace}/{$this->$field->internal_name}";
+            }
+            else {
+                $field_path = "$path/{$this->$field->internal_name}";
+            }
+
+            # Do not merge `representation_only` fields
+            if ($this->$field->representation_only) {
+                continue;
+            }
+
+            # Remove config values to fields that are `null`
+            if ($this->$field->to_internal() === null) {
+                $this->del_config(path: $field_path);
+                continue;
+            }
+
+            # Otherwise, set the value normally
+            $this->set_config(path: $field_path, value: $this->$field->to_internal());
+        }
+    }
+
     /**
      * Delete a key from the configuration
      * @param $path string path with '/' separators
@@ -907,12 +940,12 @@ class Model {
 
             # Merge differences between the stored object and updated internal object when update strategy is 'merge'
             if ($this->update_strategy === "merge") {
-                $stored_object = $this->get_config($update_config_path, []);
-                $updated_object = array_merge($stored_object, $this->to_internal());
+                $this->merge_config($update_config_path);
             }
             # Replace the internal object entirely when update strategy is 'replace'
             elseif ($this->update_strategy === "replace") {
-                $updated_object = $this->to_internal();
+                $this->set_config(path: $update_config_path, value: $this->to_internal());
+
             }
             # Throw an error if the update strategy is unknown
             else {
@@ -923,7 +956,6 @@ class Model {
             }
 
             # Write the changes to the object in config.
-            $this->set_config(path: $update_config_path, value: $updated_object);
             $this->write_config("Modified $this->verbose_name via API");
             return;
         }

pfSense-pkg-API/files/etc/inc/api/endpoints/ServicesDHCPServers.inc

@@ -12,7 +12,6 @@ class ServicesDHCPServers extends Endpoint
         # Assign the URL for this endpoint along with the Model it corresponds to.
         $this->url = "/api/v2/services/dhcp_servers";
         $this->model_name = "DHCPServer";
-        $this->
         $this->many = true;
 
         # Assign allowed request methods along with the privileges required for each

pfSense-pkg-API/files/etc/inc/api/fields/IntegerField.inc

@@ -42,8 +42,9 @@ class IntegerField extends API\Core\Field {
      * @param int $many_maximum When $many is set to `true`, this sets the maximum number of array entries allowed.
      * @param int $minimum The minimum value this value can be.
      * @param int $maximum The maximum value this value can be.
-     * @param string $delimiter Assign the delimiter used to join the value array back to its internal string form when
-     * $many is enabled.
+     * @param string|null $delimiter Assigns the string delimiter to use when writing array values to config.
+     *  Use `null` if this field is stored as an actual array in config. This is only available if $many is set to
+     *  `true`. Defaults to `,` to store as comma-separated string.
      * @param string $verbose_name The detailed name for this Field. This name will be used in non-programmatic areas
      * like web pages and help text. This Field will default to property name assigned to the parent Model with
      * underscores converted to spaces.
@@ -82,7 +83,7 @@ class IntegerField extends API\Core\Field {
         int $many_maximum = 128,
         int $minimum = 0,
         int $maximum = 99999999999999,
-        string $delimiter = ",",
+        string|null $delimiter = ",",
         string $verbose_name = "",
         string $verbose_name_plural = "",
         string $internal_name = "",

pfSense-pkg-API/files/etc/inc/api/fields/InterfaceField.inc

@@ -46,8 +46,9 @@ class InterfaceField extends API\Fields\StringField {
      * @param bool $many If `true`, the value must be an array of many strings.
      * @param int $many_minimum When $many is set to `true`, this sets the minimum number of array entries required.
      * @param int $many_maximum When $many is set to `true`, this sets the maximum number of array entries allowed.
-     * @param string $delimiter Assign the delimiter used to join the value array back to its internal string form when
-     * $many is enabled.
+     * @param string|null $delimiter Assigns the string delimiter to use when writing array values to config.
+     *  Use `null` if this field is stored as an actual array in config. This is only available if $many is set to
+     *  `true`. Defaults to `,` to store as comma-separated string.
      * @param string $verbose_name The detailed name for this Field. This name will be used in non-programmatic areas
      * like web pages and help text. This Field will default to property name assigned to the parent Model with
      * underscores converted to spaces.
@@ -88,7 +89,7 @@ class InterfaceField extends API\Fields\StringField {
         bool $many = false,
         int $many_minimum = 1,
         int $many_maximum = 128,
-        string $delimiter = ",",
+        string|null $delimiter = ",",
         string $verbose_name = "",
         string $verbose_name_plural = "",
         string $internal_name = "",

pfSense-pkg-API/files/etc/inc/api/fields/StringField.inc

@@ -43,8 +43,9 @@ class StringField extends API\Core\Field {
      * @param int $many_maximum When $many is set to `true`, this sets the maximum number of array entries allowed.
      * @param int $minimum_length The minimum number of characters required for this string field.
      * @param int $maximum_length The maximum number of characters allowed by this string field.
-     * @param string $delimiter Assign the delimiter used to join the value array back to its internal string form when
-     * $many is enabled.
+     * @param string|null $delimiter Assigns the string delimiter to use when writing array values to config.
+     *  Use `null` if this field is stored as an actual array in config. This is only available if $many is set to
+     *  `true`. Defaults to `,` to store as comma-separated string.
      * @param string $verbose_name The detailed name for this Field. This name will be used in non-programmatic areas
      * like web pages and help text. This Field will default to property name assigned to the parent Model with
      * underscores converted to spaces.
@@ -84,7 +85,7 @@ class StringField extends API\Core\Field {
         int $many_maximum = 128,
         int $minimum_length = 0,
         int $maximum_length = 1024,
-        string $delimiter = ",",
+        string|null $delimiter = ",",
         string $verbose_name = "",
         string $verbose_name_plural = "",
         string $internal_name = "",

pfSense-pkg-API/files/etc/inc/api/models/DHCPServer.inc

@@ -206,7 +206,8 @@ class DHCPServer extends Model
         );
         $this->denyunknown = new StringField(
             default: null,
-            choices: ["enabled", "class"],
+            choices: ["", "enabled", "class"],
+            allow_empty: true,
             allow_null: true,
             help_text: "Define how to handle unknown clients requesting DHCP leases. When set to `null`, any DHCP ".
             "client will get an IP address within this scope/range on this interface. If set to `enabled`, ".