I have an EventListener that listens to the entire document and records keystrokes, but I want to remove this Listener when certain conditions are met.
The following is a snippet of my code:
document.addEventListener('keyup', function(e) {
var letter_entered = String.fromCharCode(e.keyCode).toLowerCase();
player.makeGuess(letter_entered);
if(player.win_status === true || player.lose_status === true) {
document.removeEventListener('keyup', arguments.callee, false);
}
});
This works, however according to the Mozilla Developer Docs this method has been deprecated.
I'm aware that I can simply name the function, but is there an alternative that would allow me to continue using the unnamed function ?
Use the following process:
Use it as such:
var foo = function(e)
{
"use strict";
console.log(e);
document.removeEventListener('keyup', foo, false);
}
document.addEventListener('keyup', foo);
You can solve this problem easily using the y
combinator:
function y(f) {
return function () {
return f.bind(null, y(f)).apply(this, arguments);
};
}
Now you can rewrite your code as follows:
document.addEventListener("keyup", y(function (callee, e) {
player.makeGuess(String.fromCharCode(e.keyCode).toLowerCase());
if (player.win_status || player.lose_status) document
.removeEventListener("keyup", callee);
}));
That's all folks.
Use another anonymous function as a wrapper to store a named function (callee shim) to your original function:
document.addEventListener('keyup', (function(e)
{
var aFunction = function()
{
var letter_entered = String.fromCharCode(e.keyCode).toLowerCase();
player.makeGuess(letter_entered);
};
if(player.win_status === true || player.lose_status === true)
{
document.removeEventListener('keyup', window, false);
}
else
{
aFunction();
}
}
), false);
References
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.