Event listener for detecting hour - javascript

I'm doing a simple script for detecting when it's 12 o'clock, that it shows a certain div, if not that it remains hidden. So the general idea is this:
function displayDiv() {
d = new Date();
if(12 === d.getHours()){
idMain.style.display = 'block';
} else {
idMain.style.display = 'none';
}
}
But I want that in an event listener so when it's that hour it automatically displays the div or hides it. Something like:
document.addEventListener(d.getHour() === 12, displayDiv);
Or something like that but I don't know how to establish the parameters to get the desired response or for it to work.
Thanks

You can use a setInterval to run the function every minute (60000 milliseconds).
function displayDiv() {
d = new Date();
if(12 === d.getHours()){
idMain.style.display = 'block';
} else {
idMain.style.display = 'none';
}
}
setInterval(displayDiv, 60000);

I completely agree with Hev1 solution of using the setInterval (use his implementation). Here is some additional information though:
setInterval takes 2 arguments. The first argument is the callback function which you want to execute at a specific time interval. And the second argument is the amount of miliseconds you want the function to execute.
Also I want to point out if you ever are in need of clearing the interval there is also a function for this call clearInterval. You have to store the interval in an variable for this, here is an example:
const myInterval = setInterval(increase, 1000);
let index = 5;
function increase() {
if (index === 0) {
clear();
} else {
console.log(index);
index--;
}
}
function clear() {
clearInterval(myInterval);
console.log('interval cleared');
}
After the interval is stored in a variable the clear() method gets called when the interval reaches 0. In the clear function clearInterval is called to remove the interval.

We can put the if condition using following current time values.
var dates = new Date();
var hours = dates.getHours(); var minutes = dates.getMinutes();

Related

JS Func. logs message with time interval

Was hoping to find some help complete this question.
logs the message parameter to the console every (Number Parameter). Implement an html button to start and stop this sequence.
In attempting the question I was able to get this so far.
var displayLog = function Container(param) {
var message = 'any string'; // Local message variable
var timeCount = "10"; // Local time count variable
setInterval(function getLoggeddemo(message,timeCount) {
console.log(message);
return getLoggeddemo;
}(), timeCount);
}
The question is asking to display a message every (x) seconds, when a button is toggled between start & stop. I'm currently trying to figure out how to include an if/else statement to start and stop the sequence with an Html button .
A few issues:
Don't call the function you want to pass to to setInterval: so remove the parentheses after the function body.
You never seem to call displayLog.
timeCount is supposed to be a number, not a string: it is the number of milliseconds the interval lasts.
There is no influence of the button clicks on the interval logic.
Returning something in a setInterval callback has no meaning. Also the arguments will not be provided to that callback: remove those parameters.
I would suggest not to add/remove event listeners, but to use a boolean variable that indicates the state you are in, and depending on that perform the appropriate action in one, single click handler:
var i = 0;
var displayLog = function Container(message) {
console.log(i++, message);
// Return the id of the interval
return setInterval(function getLoggeddemo() { // no arguments here
console.log(i++, message);
}, 1000); // Every second
}
var mixBut = document.getElementById("mixBut");
var interval = null;
mixBut.addEventListener("click", toggle);
function toggle(){
if (interval === null) {
mixBut.value = "Stop";
interval = displayLog("Hi there!");
} else {
mixBut.value = "Start";
clearInterval(interval);
interval = null;
}
}
<button id="mixBut">Mix</button>

Javascript - Pausing an IIFE output that has setTimeout and displays min/sec - Pomodoro Clock

I have two functions that display minutes and seconds. Inside the functions I'm using an IIFE with a setTimeout to calculate the time. After getting this, having a hard time figuring out how I could pause the display if pause button is clicked.
The timer works fine and displays correctly.
I realize this is probably not a good way to do it, but I spent so much time (trying to learn how to use IIFE) that I don't want to give up. If I have to, then I will scratch it.
Update - This timer will be getting input from the user. It might be 25 minutes. I want it to start counting down from there until it reaches 0, and the user able to pause at anytime.
let convertToSeconds = document.getElementById('timeValue').value * 60;
let seconds = 60;
function secondsCounter(time) {
// let flag = document.getElementById('pauseButton').value;
for (let i = seconds; i > 0; i--) {
(function(x) {
setTimeout(function() {
let remaining = seconds - x;
document.getElementById('displaySeconds').innerHTML = remaining;
console.log(remaining);
}, i * 1000);
})(i);
}
}
function counter() {
for (let i = convertToSeconds; i > 0; i--) {
(function(minutes) {
setTimeout(function() {
let remaining = Math.floor((convertToSeconds - minutes) / 60);
document.getElementById('displayMinutes').innerHTML = remaining;
console.log(remaining);
}, i * 1000);
setTimeout(function() {
secondsCounter(seconds);
}, i * 60000);
})(i);
}
secondsCounter(seconds);
}
I've tried a couple of things.
Using a flag and if statement around document.getElementById('displaySeconds').innerHTML = remaining; so if my pause button is clicked, the flag changes, and another setTimeout (10 minutes) is triggered. Doesn't stop the countdown on the DOM, it keeps going. I just wanted to see some reaction, but nothing happened. Something like:
function secondsCounter(time) {
let flag = document.getElementById('pauseButton').value;
for (let i = seconds; i > 0; i--) {
(function(x) {
setTimeout(function() {
let remaining = seconds - x;
if (flag === 'yes') {
document.getElementById('displaySeconds').innerHTML = remaining;
console.log(remaining);
} else {
setTimeout(function() {
console.log(remaining);
}, 10000);
}
}, i * 1000);
})(i);
}
}
Using a setInterval and clearInterval that didn't do anything.
Is this possible? Not sure where else to look. Thank you
You can't stop/pause a setTimeout or clearTimeout without making a reference to the timer, storing it and then calling clearTimeout(timer) or clearInterval(timer).
So, instead of: setTimeout(someFunciton)
You need: timer = setTimeout(someFunciton)
And, the timer variable needs to be declared in a scope that is accessible to all functions that will use it.
See setTimeout() for details.
Without a reference to the timer, you will not be able to stop it and that's caused you to go on a wild goose chase for other ways to do it, which is overthinking what you actually need.
In the end, I think you should just have one function that does all the counting down so that you only have one timer to worry about.
Lastly, you can use the JavaScript Date object and its get / set Hours, Minutes and Seconds methods to take care of the reverse counting for you.
(function() {
// Ask user for a time to start counting down from.
var countdown = prompt("How much time do you want to put on the clock? (hh:mm:ss)");
// Take that string and split it into the HH, MM and SS stored in an array
var countdownArray = countdown.split(":")
// Extract the individual pieces of the array and convert to numbers:
var hh = parseInt(countdownArray[0],10);
var mm = parseInt(countdownArray[1],10);
var ss = parseInt(countdownArray[2],10);
// Make a new date and set it to the countdown value
var countdownTime = new Date();
countdownTime.setHours(hh, mm, ss);
// DOM object variables
var clock = null, btnStart = null, btnStop = null;
// Make a reference to the timer that will represent the running clock function
var timer = null;
window.addEventListener("DOMContentLoaded", function () {
// Make a cache variable to the DOM element we'll want to use more than once:
clock = document.getElementById("clock");
btnStart = document.getElementById("btnStart");
btnStop = document.getElementById("btnStop");
// Wire up the buttons
btnStart.addEventListener("click", startClock);
btnStop.addEventListener("click", stopClock);
// Start the clock
startClock();
});
function startClock() {
// Make sure to stop any previously running timers so that only
// one will ever be running
clearTimeout(timer);
// Get the current time and display
console.log(countdownTime.getSeconds());
countdownTime.setSeconds(countdownTime.getSeconds() - 1);
clock.innerHTML = countdownTime.toLocaleTimeString().replace(" AM", "");
// Have this function call itself, recursively every 900ms
timer = setTimeout(startClock, 900);
}
function stopClock() {
// Have this function call itself, recursively every 900ms
clearTimeout(timer);
}
}());
<div id="clock"></div>
<button id="btnStart">Start Clock</button>
<button id="btnStop">Stop Clock</button>

Wait before a javascript function can be called again

I've looked at many different solutions to this, none of which worked. I know it has something to do with setTimeout, but I don't know how to implement it properly.
function myfunction()
{
//the function
//wait for 1 second before it can be ran again
}
To clarify: I don't want to call the function at a regular interval, I want to be able to enforce a delay before the function can be called again.
var lastTime = 0;
function myFunction() {
var now = new Date().getTime(); // Time in milliseconds
if (now - lasttime < 1000) {
return;
} else {
lastTime = now;
}
// rest of function
}
You don't need to use setTimeout at all. The following is similar to other answers, but uses a closure to remember the last time the function ran rather than a global variable.
var myFunction = function() {
var lastTime = new Date();
return function() {
var now = new Date();
if ((now - lastTime) < 1000) return;
lastTime = now;
/* do stuff */
};
}());
I think the easiest solution would be to hold a boolean variable and reset it to true after a given delay.
fiddle
HTML
<button id="clickme">click me!</button>
JavaScript
var canGo = true,
delay = 1000; // one second
var myFunction = function () {
if (canGo) {
canGo = false;
// do whatever you want
alert("Hi!");
setTimeout(function () {
canGo = true;
}, delay)
} else {
alert("Can't go!");
}
}
$("#clickme").click(function(){
myFunction();
})
With this, you hold a boolean, canGo, and set it to true. If the function is run, it sets canGo to false and sets a setTimeout() for a time period of delay, in milliseconds. If you try to run the function again, it won't run and will, instead, alert("Can't go!"). This was just for demonstrative purposes; you don't need that part. After delay, canGo will be set to true, and you will be able to once more run the function.
var lastRan = 0;
var myFunction = function() {
var now = Date.now();
if(now-lastRan < 1000) {
return;
}
lastRan = now;
//rest of function
};
You may want to use throttle or debounce from underscore.js
http://underscorejs.org/#throttle
throttle_.throttle(function, wait, [options])
Creates and returns a
new, throttled version of the passed function, that, when invoked
repeatedly, will only actually call the original function at most once
per every wait milliseconds. Useful for rate-limiting events that
occur faster than you can keep up with.
By default, throttle will execute the function as soon as you call it
for the first time, and, if you call it again any number of times
during the wait period, as soon as that period is over. If you'd like
to disable the leading-edge call, pass {leading: false}, and if you'd
like to disable the execution on the trailing-edge, pass {trailing:
false}.
var throttled = _.throttle(updatePosition, 100);
$(window).scroll(throttled);
http://underscorejs.org/#debounce
debounce_.debounce(function, wait, [immediate])
Creates and returns a
new debounced version of the passed function which will postpone its
execution until after wait milliseconds have elapsed since the last
time it was invoked. Useful for implementing behavior that should only
happen after the input has stopped arriving. For example: rendering a
preview of a Markdown comment, recalculating a layout after the window
has stopped being resized, and so on.
Pass true for the immediate parameter to cause debounce to trigger the
function on the leading instead of the trailing edge of the wait
interval. Useful in circumstances like preventing accidental
double-clicks on a "submit" button from firing a second time.
var lazyLayout = _.debounce(calculateLayout, 300);
$(window).resize(lazyLayout);
If you just want to run your function again after a set time, you can use setTimeout and pass it the function to run and the delay period in milliseconds.
function myfunction() {
//the function
//run again in one second
setTimeout(myfunction, 1000);
}
Edited based on poster's comments:
var waiting = false;
var myfunction = function() {
if (!waiting) {
//Run some code
waiting = setTimeout(function() {
waiting = false;
}, 1000);
}
};

Greasemonkey delay... setTimeout doesnt work ok

I've been playing around with a site, in which I want to continue clicking a button for i amount of times every interval seconds.
My code is:
clickbidBtn1 = function() {
var bidBtn=document.getElementById("BidButton");
var interval = 15000;
for (var i=3; i>=0; i--){
setTimeout(bidBtn.click(1);,i*interval);
};
I've found out that GM executes all i amount of clicks at the same time, not with the intended delay. is there a way to delay the time of click? Say i wanted the function to click the button every 15 second for i amount of times.
I was thinking of giving it some more variables, and adding one variable in the settimeout code part, which only executes # the click, then comparing increased variables with current ones before going to the next settimeout... but haven't thought it through yet... it seems to be a complicated process for a simple process... :( i wll play around with it a bit
Use setInterval() for this.
One way:
var bidClickTimer = 0;
var numBidClicks = 0;
function clickbidBtn1 ()
{
var interval = 15000;
bidClickTimer = setInterval (function() {BidClick (); }, interval);
}
function BidClick ()
{
numBidClicks++;
if (numBidClicks > 3)
{
clearInterval (bidClickTimer);
bidClickTimer = "";
}
else
{
bidBtn.click (1);
}
}
clickbidBtn1 ();
Alternatively, without using global vars:
function clickbidBtn1 ()
{
var interval = 15000;
this.numBidClicks = 0;
this.bidClickTimer = 0;
this.BidClick = function () {
numBidClicks++;
if (numBidClicks > 3)
{
clearInterval (bidClickTimer);
bidClickTimer = "";
}
else
{
bidBtn.click (1);
}
};
this.bidClickTimer = setInterval (function(thisScope) {thisScope.BidClick (); }, interval, this);
}
clickbidBtn1 ();
Just to explain why your code does not work: You are calling the .click method immediately (putting () after a function name calls the function) and actually passing the return value of that function to setTimeout. The for loop is so fast that everything seem to happen at the same time.
You have to pass a function reference to setTimeout, e.g. an anonymous function:
setTimeout(function() {
bidBtn.click(1);
}, i*interval);

JavaScript getTimeout?

The window.setTimeout (and related setInterval) function in Javascript allows you to schedule a function to be executed sometime in the future:
id = setTimeout(function, delay);
where "delay" is the number of milliseconds into the future at which you want to have the function called. Before this time elapses, you can cancel the timer using:
clearTimeout(id);
What I want is to update the timer. I want to be able to advance or retard a timer so that the function gets called x milliseconds sooner or later than originally scheduled.
If there were a getTimeout method, you could do something like:
originally_scheduled_time = getTimeout(id);
updateTimeout(id, originally_schedule_time + new_delay); // change the time
but as far as I can tell there's nothing like getTimeout or any way to update an existing timer.
Is there a way to access the list of scheduled alarms and modify them?
Is there a better approach?
thanks!
If you really want this sort of functionality, you're going to need to write it yourself.
You could create a wrapper for the setTimeout call, that will return an object you can use to "postpone" the timer:
function setAdvancedTimer(f, delay) {
var obj = {
firetime: delay + (+new Date()), // the extra + turns the date into an int
called: false,
canceled: false,
callback: f
};
// this function will set obj.called, and then call the function whenever
// the timeout eventually fires.
var callfunc = function() { obj.called = true; f(); };
// calling .extend(1000) will add 1000ms to the time and reset the timeout.
// also, calling .extend(-1000) will remove 1000ms, setting timer to 0ms if needed
obj.extend = function(ms) {
// break early if it already fired
if (obj.called || obj.canceled) return false;
// clear old timer, calculate new timer
clearTimeout(obj.timeout);
obj.firetime += ms;
var newDelay = obj.firetime - new Date(); // figure out new ms
if (newDelay < 0) newDelay = 0;
obj.timeout = setTimeout(callfunc, newDelay);
return obj;
};
// Cancel the timer...
obj.cancel = function() {
obj.canceled = true;
clearTimeout(obj.timeout);
};
// call the initial timer...
obj.timeout = setTimeout(callfunc, delay);
// return our object with the helper functions....
return obj;
}
var d = +new Date();
var timer = setAdvancedTimer(function() { alert('test'+ (+new Date() - d)); }, 1000);
timer.extend(1000);
// should alert about 2000ms later
I believe not. A better approach might be to write your own wrapper which stores your timers (func-ref, delay, and timestamp). That way you can pretend to update a timer by clearing it and calculate a copy with an updated delay.
Another wrapper:
function SpecialTimeout(fn, ms) {
this.ms = ms;
this.fn = fn;
this.timer = null;
this.init();
}
SpecialTimeout.prototype.init = function() {
this.cancel();
this.timer = setTimeout(this.fn, this.ms);
return this;
};
SpecialTimeout.prototype.change = function(ms) {
this.ms += ms;
this.init();
return this;
};
SpecialTimeout.prototype.cancel = function() {
if ( this.timer !== null ) {
clearTimeout(this.timer);
this.timer = null;
}
return this;
};
Usage:
var myTimer = new SpecialTimeout(function(){/*...*/}, 10000);
myTimer.change(-5000); // Retard by five seconds
myTimer.change(5000); // Extend by five seconds
myTimer.cancel(); // Cancel
myTimer.init(); // Restart
myTimer.change(1000).init(); // Chain!
It may be not exactly what you want, but take a look anyway, maybe you can use it to your benefit.
There is a great solution written by my ex-coworker that can create special handler functions that can stop and start timeouts when required. It is most widely used when you need to create a small delay for hover events. Like when you want to hide a mouseover menu not exactly at the time when a mouse leaves it, but a few milliseconds later. But if a mouse comes back, you need to cancel the timeout.
The solution is a function called getDelayedHandlers. For example you have a function that shows and hides a menu
function handleMenu(show) {
if (show) {
// This part shows the menu
} else {
// This part hides the menu
}
}
You can then create delayed handlers for it by doing so:
var handlers = handleMenu.getDelayedHandlers({
in: 200, // 'in' timeout
out: 300, // 'out' timeout
});
handlers becomes an object that contains two handler functions that when being called cancel the other one's timeout.
var element = $('menu_element');
element.observe('mouseover', handlers.over);
element.observe('mouseout', handlers.out);
P.S. For this solution to work you need to extend the Function object with the curry function, which is automatically done in Prototype.
One possibility can be like this:
if (this condition true)
{
setTimeout(function, 5000);
}
elseif (this condition true)
{
setTimeout(function, 10000);
}
else
{
setTimeout(function, 1000);
}
It's up to your how you construct your conditions or the logic. thanks

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