How can I add an event for a one time click to a function?

function one(el, type, fn) {
    function handler(event) {
        el.removeEventListener(type, handler);
        fn(event);
    }
    el.addEventListener(type, handler);
}

// use it like
one(window, 'resize', function () {
    alert("This triggers just once");
});

Example: http://jsfiddle.net/6njpem7x/

You have to use removeEventListener once the event is fired once. However, removeEventListener takes a function as argument, which means you need to declare a named function, add it with addEventListener, and have it removing itself. Example:

function foo() {
    // do things, then
    removeEventListener('click', foo);
}

addEventListener('click', foo);

Use modern JavaScript!

EventTarget.addEventListener("click", function() {

    // Do something cool

}, {once : true});

A Boolean indicating that the listener should be invoked at most once after being added. If true, the listener would be automatically removed when invoked.

- MDN web docs

All modern browsers support this feature

Other reference