=================================
How to execute script from client
=================================


You can use 
:doc:`server </refs/client/abstr_item/m_server>`
method to send a request to the server to execute a function defined in the 
server module of an item.

In the example below we create the ``btn`` button that is a JQuery object. 
Then we use its click method to attach a function that calls the 
:doc:`server </refs/client/abstr_item/m_server>`
method of the item to run the ``calculate`` function defined in the server module
of the item.

The code in the client module:

.. code-block:: js

  function on_view_form_created(item) {
      var btn = item.add_view_button('Calculate', {type: 'primary'});
      btn.click(function() {
          item.server('calculate', [1, 2, 3], function(result, error) {
            if (error) {
              item.alert_error(error);
            }
            else {
              console.log(result);
            }
          })
      });
  }
  

The code in the server module:

.. code-block:: py

  def calculate(item, a, b, c):
      return a + b + c