Question

what is the event or method name that i have to call or handle to update an existing event in the calendar(the event i click on). full calendar can be found here http://arshaw.com/fullcalendar/

Answer 1

When you initialize the FullCalendar instance, bind the eventClick handler:

var calendar = $('#calendar');
var curr_event = null;
calendar.fullCalendar({
    ...

    events: [],
    eventClick: function(event, jsEvent, view) {
        curr_event = event;
        show_form_or_something();
    },

    ...
});

You might want to show a form or something in order to allow the user to modify the event properties (title, start etc). Then to update the event back in the FullCalendar instance:

$.extend(curr_event, {
    title: 'New Event Title',
    start: new Date()
});
calendar.fullCalendar('updateEvent', curr_event);

And to address jmeho question:

When you add the event to FullCalendar either through renderEvent() or event source, you can specify id for each event. After you added the event, you can retrieve the event hash/object by using:

var event_obj = calendar.fullCalendar('clientEvents', 'specific event id');

Then you can modify the has/object and use the updateEvent() method to update the FullCalendar display.