jQuery 中的去抖动功能

Question

I'm attempting to debounce a button's input using the jquery debouncing library by Ben Alman. http://benalman.com/code/projects/jquery-throttle-debounce/examples/debounce/

Currently this is the code that I have.

function foo() {
    console.log("It works!")
};

$(".my-btn").click(function() {
    $.debounce(250, foo);
});

The problem is that when I click the button, the function never executes. I'm not sure if I've misunderstood something but as far as I can tell, my code matches the example.

Answer 1

I ran into the same issue. The problem is happening because the debounce function returns a new function which isn't being called anywhere.

To fix this, you will have to pass in the debouncing function as a parameter to the jquery click event. Here is the code that you should have.

$(".my-btn").click($.debounce(250, function(e) {
    console.log("It works!");
}));

Answer 2

In my case I needed to debounce a function call that was not generated directly by a jQuery event handler, and the fact that $.debounce() returns a function made it impossible to use, so I wrote a simple function called callOnce() that does the same thing as Debounce, but can be used anywhere.

You can use it by simply wrapping the function call with a call to callOnce() , eg callOnce(functionThatIsCalledFrequently); or callOnce(function(){ doSomething(); }

/**
 * calls the function func once within the within time window.
 * this is a debounce function which actually calls the func as
 * opposed to returning a function that would call func.
 * 
 * @param func    the function to call
 * @param within  the time window in milliseconds, defaults to 300
 * @param timerId an optional key, defaults to func
 */
function callOnce(func, within=300, timerId=null){
    window.callOnceTimers = window.callOnceTimers || {};
    if (timerId == null) 
        timerId = func;
    var timer = window.callOnceTimers[timerId];
    clearTimeout(timer);
    timer = setTimeout(() => func(), within);
    window.callOnceTimers[timerId] = timer;
}