===============================================
Saving audit trail/change history made by users
===============================================

To save change history made by users to must specify the item that will 
store them. 

To do so, open project parameters and click the button to the right of the
History item input:

.. image:: _images/history_item.png
	:align: center
	:alt: History item
	
In the dialog that will appear click on the Create history item button 

.. image:: _images/new_hist_item.png
	:align: center
	:alt: New history item

The following mesage will appear when the item will be created: 

.. image:: _images/hist_item_created.png
	:align: center
	:alt: History item created
	
After that you have to set **Keep history** attribute of an item to save the history
its changes:

.. image:: _images/item_editor_dialog.png
	:align: center
	:alt: Keep history attribute
	
To see the history of changes of a record click the icon to the left of 
the close button on the right part of the header of the edit form.


.. image:: _images/invoices_hist.png
	:align: center
	:alt: Invoices history


Or you can do it using the
:doc:`show_history </refs/client/item/m_show_history>`
method

.. note::

    Changes are saved when dataset changes are applied to the database using
    apply method (:doc:`client </refs/client/item/m_apply>`/:doc:`server </refs/server/item/m_apply>`).
    Changes to database made with custom SQL requests are not saved in the history. 
    
.. note::

    These changes can significantly increase the size of the database.
    Please be careful.
    
