I am programming a little timer. The code is as follows:
var counter = {
seconds: 100,
clock: function () {
$('input').val(this.seconds);
this.seconds -= 1;
setTimeout(this.clock(), 1000);
}
};
counter.clock();
with a working example on http://jsfiddle.net/4ktEG/
Somehow each time I run the code I get a different answer. What is the problem?
This does the countdown you're looking for.
var counter = {
seconds: 100,
clock: function () {
$('input').val(this.seconds);
this.seconds -= 1;
setTimeout(function(){counter.clock()}, 1000);
}
};
counter.clock();
jQuery has the jQuery.proxy()[docs] method for binding the this value.
setTimeout($.proxy(counter,'clock'), 1000);
The $.proxy will return a function that invokes counter.clock with counter bound as the this value.
Or you can use it like this to permanently bind counter to counter.clock:
var counter = {
seconds: 100
};
counter.clock = $.proxy( function () {
$('input').val(this.seconds);
this.seconds -= 1;
setTimeout(this.clock, 1000);
}, counter);
counter.clock();
Example: http://jsfiddle.net/bmYAN/
If you want the input to show "100", then disappear when the setTimeout is called, then you have to take out the brackets on "this.clock()"
Therefor:
var counter = {
seconds: 100,
clock: function () {
$('input').val(this.seconds);
this.seconds -= 1;
setTimeout(this.clock, 1000);
}
};
counter.clock();
When you say
setTimeout(this.clock(), 1000); //the clock method will be called right away.
Use this instead
setTimeout(this.clock, 1000);
Use:
var counter = {
seconds: 100,
clock: function () {
$('input').val(counter.seconds);
counter.seconds -= 1;
setTimeout(counter.clock, 1000);
}
};
counter.clock();
You used "this" inside a function, what you want is to refer to the "counter" object.
The timeout will execute in a global context. Hence the 'this' inside the handler will refer to the global context. You have to bind the function to the wanted context to achieve the desired result. Look into function.call or function.apply which take a context parameter.
var counter = {
seconds: 100,
clock: function () {
$('input').val(this.seconds);
this.seconds -= 1;
var closure = function() {
counter.clock.call(counter);
};
setTimeout(closure, 1000);
}
};
counter.clock();
