Form field "preset" options can be a string that just specifies the other field, defaults to url type

CHANGELOG.md

@@ -1,3 +1,6 @@
+* **Build 21x** (2015-03-xx)
+  - Form fields can now use a simpler interface for using the Input preset converter (see Backend > Forms docs).
+
 * **Build 217** (2015-03-06)
   - Improvements made to the user menu in the back-end: clicking your avatar will display a popover with settings links from the `mysettings` context.
   - Added new form field widget called `repeater` for repeatable fields (see Backend > Forms docs).

modules/backend/classes/FormField.php

@@ -435,9 +435,13 @@ class FormField
      */
     protected function filterPresetAttributes($attributes, $position = 'field')
     {
-        if (!$this->preset || !is_array($this->preset) || $position != 'field')
+        if (!$this->preset || $position != 'field')
             return $attributes;
 
+        if (!is_array($this->preset)) {
+            $this->preset = ['field' => $this->preset, 'type' => 'slug'];
+        }
+
         $presetField = array_get($this->preset, 'field');
         $presetType = array_get($this->preset, 'type');