bind event only once

In addition to pna's answer you may wish to think about namespacing your event so you do not go around unbinding all the click events accidentally.

function someMethod() {
    $(obj).unbind('click.namespace').bind('click.namespace', function() { });
}

https://api.jquery.com/event.namespace/

There is no built in method to determine if you have already bound this particular function. You can bind multiple click functions to an object. For example:

$('#id').bind('click', function(){
alert('hello');
});


$('#id').bind('click', function(){
alert('goodbuy');
});

if you do the above when the object is clicked it will alert hello then goodbye. To make sure only one function is bound to the click event unbind the click event handler then bind the desired function like this:

$(obj).unbind('click').bind('click', function(){... });

Or use jQuery's one() function which is similar to on() but only fires the event once, even if you bind it multiple times.

http://api.jquery.com/one/

If you can apply it, probably want to take a look at event.preventDefault and event.stopPropagation OR unbind and bind each time, within your method like

function someMethod()
{
  $(obj).off('click').on('click', function(e) {
    // put your logic in here 
  });
}