im trying to use the jquery fullcalendar. The event data comes from the server using JSON. My page has a dropdown element and the fullcalendar div.
What i need is to
I solved like this
         data: function() { // a function that returns an object
         return {
                 custom_param1: date_start,
             custom_param2: date_end
            };
         },
after modifying the values date_start and date_end, this function gets the new values. In my case i take the dates when the view changes
viewRender: function(view,element){
       date_start = $.fullCalendar.formatDate(view.start,'dd/MM/yyyy');
       date_end   = $.fullCalendar.formatDate(view.end,'dd/MM/yyyy');
},
This can be achieved by using function as event source. On refetchEvents event fullCalendar calls function that returns custom value and will post it to service.
$(document).ready(function() {
        $('#valueSelect').change(function(){
            if ($('#calendar').hasClass('fc'))
            {
                $('#calendar').fullCalendar('refetchEvents');
            }
            else
            {
                $('#calendar').fullCalendar({
                    events: function(start, end, callback) {
                        $.ajax({
                            url: 'web-service-link',
                            type: 'GET',
                            dataType: "json",
                            contentType: "application/json; charset=utf-8",
                            data: {
                                start: Math.round(start.getTime() / 1000),
                                end: Math.round(end.getTime() / 1000),
                                customValue: GetCustomValue()
                            }
                        });
                    }
                });
            }
        });
});
function GetCustomValue()
{
    return $('#valueSelect').val();
{
This is right way.
$.ajax({
    url: 'ABC.com/Calendar/GetAllCalendar/',
    type: 'POST',
    async: false,
    data: { Id: 1 },
    success: function (data) {
        obj = JSON.stringify(data);
    },
    error: function (xhr, err) {
        alert("readyState: " + xhr.readyState + "\nstatus: " + xhr.status);
        alert("responseText: " + xhr.responseText);
    }
});
/* initialize the calendar
-----------------------------------------------------------------*/
var date = new Date();
var d = date.getDate();
var m = date.getMonth();
var y = date.getFullYear();
var calendar = $('#calendar').fullCalendar({
    //isRTL: true,
    buttonHtml: {
        prev: '<i class="ace-icon fa fa-chevron-left"></i>',
        next: '<i class="ace-icon fa fa-chevron-right"></i>'
    },
    header: {
        left: 'prev,next today',
        center: 'title',
        right: 'month,agendaWeek,agendaDay'
    },
    //obj that we get json result from ajax
    events: JSON.parse(obj)
    ,
    editable: true,
    selectable: true    
});
Finally it worked with the following code:
$(document).ready(function() {
        loadCalendar();
        $('#siteSelect').change(function(){
            var selectedSite = $('#siteSelect').val();
            var events = {
                  url: '/myfeed2',
                  type: 'POST',
                  data: {
                    siteid: selectedSite
                  }
            }
            $('#calendar').fullCalendar('removeEventSource', events);
            $('#calendar').fullCalendar('addEventSource', events);
        });
    });
The problem is that you are changing the value of the dropdown after you have created the event object, which has a copy of the original value of the dropdown. The following is what you need:
$('#dropdownId').change(function () {
    events.data.customParam = $(this).val();
    $('#calendar').fullCalendar('refetchEvents');
});
This relies on the event object being created in an area where it can be accessed from the dropdown onchange and the fullcalendar initialisation (e.g. document onload)
I just ran into this myself and there is a more dynamic way of doing this since the value is stored when the calendar is initialized and the data object needs modified.
 $(document).ready(function() {
        $('#calendar').fullCalendar({
            events: {
                url : '/myfeed',
                data : {personId : $('#personDropDown').val() }
            }
        });
        $('#personDropDown').change(function(){
            $('#calendar').data('fullCalendar').options.events.data.personId = $(this).val();
            $('#calendar').fullCalendar('refetchEvents');
        });
    });