==========
field_mask
==========

.. js:attribute:: field_mask

**domain**: client 

**language**: javascript

**class** :doc:`Field class </refs/client/field_api>`


Description
===========

You can use **field_mask** attribute to specify the name of the field that appears to 

The mask allows a user to more easily enter fixed width input where you would 
like them to enter the data in a certain format (dates,phone numbers, etc). 

A mask is defined by a format made up of mask literals and mask definitions. 
Any character not in the definitions list below is considered a mask literal. 
Mask literals will be automatically entered for the user as they type and will 
not be able to be removed by the user.The following mask definitions are predefined:

* a - Represents an alpha character (A-Z,a-z)
* 9 - Represents a numeric character (0-9)
* `*` - Represents an alphanumeric character (A-Z,a-z,0-9)


Example
=======

.. code-block:: js

    function on_edit_form_created(item) {
        item.phone.field_mask = '999-99-99';
    }