===============
on_before_apply
===============

on_before_apply(item)

**domain**: client 

**language**: javascript

**class** :doc:`Item class </refs/client/item_api>`

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

Occurs before an application applies saves the change log to the project 
database.

The ``item`` parameter is an item that triggered the event.

Write an on_before_apply event handler to take specific action immediately before 
an application saves the change log to the project database.

``on_after_apply`` is triggered by
:doc:`apply <m_apply>`
method.

See also
========

:doc:`Modifying datasets </programming/data/modifying_datasets>`
