[reference][forms] Adding the percent type

Author: weaverryan

reference/forms/types/percent.rst

@@ -4,4 +4,43 @@
 ``percent`` Field Type
 ======================
 
-See :class:`Symfony\\Component\\Form\\Type\\PercentType`.
+
+The ``percent`` type renders an input text field and specializes in handling
+percentage data. If your percentage data is stored as a decimal (e.g. ``.95``),
+you can use this field out-of-the-box. If you store your data as a number
+(e.g. ``95``), you should set the ``type`` option to ``integer``.
+
+This field adds a percentage sign "``%``" after the input box.
+
+============ ======
+Rendered as ``input`` ``text`` field
+Options ``type``, ``required``, ``label``, ``read_only``, ``error_bubbling``
+Parent type ``field``
+Class :class:`Symfony\\Component\\Form\\Type\\PercentType`
+============ ======
+
+Options
+-------
+
+* ``type`` [type: string, default: ``fractional``]
+ This controls how your data is stored on your object. For example, a percentage
+ corresponding to "55%", might be stored as ``.55`` or ``55`` on your
+ object. The two "types" handle these two cases:
+ 
+ * ``fractional``
+ If your data is stored as a decimal (e.g. ``.55``), use this type.
+ The data will be multiplied by ``100`` before being shown to the
+ user (e.g. ``55``). The submitted data will be divided by ``100``
+ on form submit so that the decimal value is stored (``.55``);
+ * ``integer``
+ If your data is stored as an integer (e.g. 55), then use this option.
+ The raw value (``55``) is shown to the user and stored on your object.
+ Note that this only works for integer values.
+
+.. include:: /reference/forms/types/options/required.rst.inc
+
+.. include:: /reference/forms/types/options/label.rst.inc
+
+.. include:: /reference/forms/types/options/read_only.rst.inc
+
+.. include:: /reference/forms/types/options/error_bubbling.rst.inc