将附加参数传递给事件回调函数

Question

I need to pass additional arguments to a function on an event.

I tried bind but it only passes the e and not the result data :

locationSearch.on("result", dropMarker.bind(this, e) );

I could do:

locationSearch.on("result", function(data) {
    dropMarker({ 
        e: e,
        data: data
    });
};

... but then I can't disable the listener locationSearch.off(...) since it is an anonymous function.

Answer 1

Just wrap the function call in another function that will become the callback

locationSearch.on("result", wrapper);

function wrapper(e) { dropMarker(e, data); }

Here's an example:

 $("button").on("click", wrapper); let data = "some data"; function wrapper(e){ // The wrapper just calls the actual handler handler(e, data); } function handler(e, data){ // Because the wrapper was named, it can be disconnected $(e.target).off("click", wrapper); // And you can do whatever you need to console.log(e.type, data); }

 <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <button>Click Me</button>

Answer 2

Just name a function and then call it:

function handler(e) {
    dropMarker({ e: e, data: data });
}

locationSearch.on("result", handler);