I have two functions for eg., runslider() and runslider1().
runslider() runs after the document is loaded and I need to call runslider1() after finishing runslider(). Then again runslider() after runslider1(). This process should happen like infinite loop. Can someone help me please.
I have tried to keep them like callbacks. But that didn't work.
function runSlider(runslider1){
alert("run")
runSlider1(runSlider());
}
function runSlider1(runslider){
alert("run1");
runSlider(runSlider1());
}
if you want your functions to be called over and over again try using setInterval
function runSlider(){
alert("run");
runSlider1();
}
function runSlider1(){
alert("run1");
}
setInterval(runSlider, 100);
This will cause both functions to be called in that order repeatedly every 100ms. It seems like this is the behavior you are looking for.
The comments above are correct - you will cause a stack overflow.
Don't know why you would need this, but I cleaned your code for you:
function runSlider() {
alert('run');
runSlider1();
}
function runSlider1() {
alert('run1');
runSlider();
}
You can create infinite loop like this you just need to call one function.
var runSlider = function() {
console.log("run")
runSlider1()
}
var runSlider1 = function() {
console.log("run1");
setTimeout(function() {
runSlider()
}, 1000)
}
runSlider()
Another solution is:
function runSlider() {
console.log("run");
runSlider1();
setTimeout(runSlider1(), 1000) // Calls runSlider1() after 1 second(1000 millisecond). You can change it.
}
function runSlider1() {
console.log("run1");
setTimeout(runSlider(), 1000) // Calls runSlider1() after 1 second(1000 millisecond).
}
runSlider(); // Starts the cycle
var maxCalls = 0;
function run1(cb) {
alert('run1');
if (maxCalls++ < 5) { //Added this to avoid an infinite loop
cb(run1); //We want the function run after cb to be this one
}
}
function run2(cb) {
alert('run2');
if (maxCalls++ < 5) {
cb(run2);
}
}
This is the way to call one function from another. If you create an infinite loop, you will freeze the browser up. If you want the two functions running constantly, its best to release execution for a bit with a setInterval call instead.
var runFunc = 0;
var run1 = function() {
alert('run1');
};
var run2 = function() {
alert('run2');
};
var run = function() {
!(++runFunc) ? run2 : run1; //Alternate between calling each function
}
var stopRunning = function() { //Call this to stop the functions running
clearInterval(runInterval);
};
var runInterval = setInterval(run, 1000); //Calls the function every second
Related
I got this code, it's supposed to toggle elements, following a repetitive patron, that will grow up randomly, my start function executes my runp() function at simultaneous, and it got all messy. i would need to wait until runp() finishes to continue executing. Thanks
function runp(patron){
var x = 0;
var intervalID = setInterval(function () {
$("#container"+patron[x]).toggle(1).delay(1000).toggle(1).delay(1000);
if (++x === 20) {
window.clearInterval(intervalID);
}
}, 2000);
}
function start(patron, patronl){
while (patron.length<20){
patron.push(rand(1,4));
runp(patron);
}
}
You can use .queue()
// alternatively pass randomly shuffled array of elements to `$.map()`
$({}).queue("toggle", $.map($("[id^=container]"), function(el) {
return function(next) {
return $(el).toggle(1).delay(1000).toggle(1).delay(1000)
.promise().then(next)
}
})).dequeue("toggle")
I think im missing something fairly obvious with how the clearInterval method works.
So with the code below. I would expect the first function call to execute testFunction and set the interval to repeat the function. The 2nd call would execute the second function which will remove the interval from the 1st function. As this would execute far before the 5000ms interval the first function would not be executed again. However it does not behave like this.
Could someone please explain what is wrong with my method?
Reason for this is in a program I am writing I am making repeated get requests, every 30 seconds or so , using setTimeout but i would like a method to easily remove this interval at other points in the program
function testFunction() {
$("#test").append("test");
setTimeout(testFunction, 5000);
}
function stopFunction() {
clearTimeout(testFunction);
}
testFunction();
stopFunction();
setTimeout returns an ID so you should
var timeoutID = setTimeout(blah blah);
clearTimeout(timeoutID);
setTimeout returns an object that you need to pass into the clearTimeout method. See this article for an example: http://www.w3schools.com/jsref/met_win_cleartimeout.asp
setTimeout returns an identifier for the timer. Store this in a variable like:
var timeout;
function testFunction(){
...
timeout = setTimeout(testFunction, 5000);
}
function stopFunction(){
clearTimeout(timeout);
}
Here is a simple and I think better implementation for this .
var _timer = null,
_interval = 5000,
inProgress = false,
failures = 0,
MAX_FAILURES = 3;
function _update() {
// do request here, call _onResolve if no errors , and _onReject if errors
}
function _start() {
inProgress = true;
_update();
_timer = setInterval(_update, _interval);
}
function _end() {
inProgress = false;
clearInterval(_timer);
}
function _onReject(err) {
if (failures >= MAX_FAILURES) {
_end();
return false;
}
_end();
failures++;
_start();
}
function _onResolve(response) {
return true;
}
I want call few function one after another recursively with setTimeout.
var flag = 0 ;
function slave1(){
if(flag < 60) {
var COPY_PO_LINE_DIV = document.getElementById("DOM_ELEMENT1"); // Checking if DOM has loaded or not. If yes then doing something.
if (COPY_PO_LINE_DIV != null) {
flag = 0;
//doing something
} else {
setTimeout(slave1,2000); //waiting for 2 seconds and checking again.
}
}
}
//doing similar task
function slave2(){
if(flag < 60) {
var COPY_PO_LINE_DIV = document.getElementById("DOM_ELEMENT2");
if (COPY_PO_LINE_DIV != null) {
flag = 0;
//doing something
} else {
setTimeout(slave2,2000);
}
}
}
function master() {
slave1();
console.log("Without completing slave1 function.");
slave2();
}
Through master() function I want to call multiple functions one after another, however in current situation its calling slave2() without completing slave1(). How can I make sure that slave1() has executed completed. If DOM element is not loaded than it should execute 60 times after every 2 seconds and than it should come out from slave1() and go to next one.
I want to execute same function for 60 times if dom element is not loaded without returning the control to next function.
You need to adjust slave1 to run a callback when it is finished which will be slave2.
function slave1(callback){
if(flag < 60) {
var COPY_PO_LINE_DIV = document.getElementById("DOM_ELEMENT1"); // Checking if DOM has loaded or not. If yes then doing something.
if (COPY_PO_LINE_DIV != null) {
flag = 0;
//doing something
callback();
} else {
setTimeout(slave1,2000); //waiting for 2 seconds and checking again.
}
}
}
function slave2(){...}
function master() {
slave1(slave2);
console.log("Without completing slave1 function.");
}
This is your basic javascript chaining. If you have more slaves you might want to look into async.series otherwise you go into callback hell as Gabs00 has put it nicely:
slave1(function(){
slave2(function(){
slave3(function(){
slave4(slave5);
});
});
});
If you need to pass values to callbacks then you need to use an intermediate anonymous function which in turn calls the intended callback with the arguments in question. To do that, you need define your functions so that they use the arguments:
function slave1(str, callback){...}
function slave3(i, callback){...}
slave1("some argument", function(){
slave2("another argument", function(){
slave3(1, function(){
slave4(2, slave5);
});
});
});
Consider using promises for things like that. Here an implementation on top of jQuery, other promise libraries work similarly.
function waitForElement(elementId, maxTries, checkInterval) {
var d = $.Deferred(), intvalID, checkFunc;
// set up default values
maxTries = maxTries || 60;
checkInterval = checkInterval || 2000;
checkFunc = function () {
var elem = document.getElementById(elementId);
if (maxTries-- > 0 && elem) {
clearInterval(intvalID);
d.resolve(elem);
}
if (maxTries <= 0) {
clearInterval(intvalID);
d.reject(elementId);
}
};
// set up periodic check & do first check right-away
intvalID = setInterval(checkFunc, checkInterval);
checkFunc();
return d.promise();
}
Now, if you want to test for elements one after another, you can cascade the calls like this:
function master() {
waitForElement("DOM_ELEMENT1").done(function (elem1) {
waitForElement("DOM_ELEMENT2").done(function (elem2) {
alert("elem1 and elem2 exist!");
// now do something with elem1 and elem2
}).fail(function () {
alert("elem1 exists, but elem2 was not found.");
});
}).fail(function () {
alert("elem1 not found.");
});
}
or you can do it in parallel and have a callback called when all of the elements exist:
function master() {
$.when(
waitForElement("DOM_ELEMENT1"),
waitForElement("DOM_ELEMENT2")
)
.done(function (elem1, elem2) {
alert("elem1 and elem2 exist!");
// now do something with elem1 and elem2
})
.fail(function () {
alert("not all elements were found before the timeout");
});
}
Your slave2 function should be passed to slave1 function as a callback and should be called in slave1 after it finishes (if ever?). Your current situation is quite common, since setTimeout() function is asynchronous, thus JS interpreter doesn't wait till the function is completed, but sets the setTimeout() result at the end of the Evet Loop and continues processing the master() method.
In order to pass arguments to functions, creating anonymous functions turns out to be an overkill. Consider using "bind" instead. So, if you've got
function slave1(str, callback){...}
function slave2(str, callback){...}
function slave3(i, callback){...}
function slave4(i, callback){...}
function slave5()
Instead of using
slave1("some argument", function(){
slave2("another argument", function(){
slave3(1, function(){
slave4(2, slave5);
});
});
});
Consider using
slave1("some argument",
slave2.bind(null, "another argument",
slave3.bind(null, 1,
slave4.bind(null, 2, slave5)
)
)
);
Much easier, more efficient in terms of memory and CPU utilization.
Now, how to do this with setTimeout:
slave1("some argument",
setTimeout.bind(null, slave2.bind(null, "another argument",
setTimeout.bind(null, slave3.bind(null, 1,
setTimeout.bind(null, slave4.bind(null, 2,
setTimeout.bind(null, slave5, 0)
),0)
),0)
),0)
);
I explained the problem in more detail at
http://morethanslightly.com/index.php/2014/09/executables-the-standard-solution-aka-mind-the-bind/
I have a setInterval loop. It's set to 3500 milliseconds, like so:-
var loop = setInterval(function() { /*stuff*/ }, 3500);
At one point in 'stuff' if a certain situation occurs, I want to force a new iteration of the loop and NOT WAIT for the 3500 milliseconds. How is that possible? Is it continue or do I just need to frame the process differently?
You could try writing an anonymous self-calling function using setTimeout instead of setInterval:
var i = 0;
(function() {
// stuff
i++;
if (i % 2 == 0) {
// If some condition occurs inside the function, then call itself once again
// immediately
arguments.callee();
} else {
// otherwise call itself in 3 and a half seconds
window.setTimeout(arguments.callee, 3500);
}
})(); // <-- call-itself immediately to start the iteration
UPDATE:
Due to a disagreement expressed in the comments section against the usage of arguments.callee, here's how the same could be achieved using a named function:
var i = 0;
var doStuff = function() {
// stuff
i++;
if (i % 2 == 0) {
// If some condition occurs inside the function, then call itself once again
// immediately
doStuff();
} else {
// otherwise call itself in 3 and a half seconds
window.setTimeout(doStuff, 3500);
}
};
doStuff();
You can use something like this... using setTimeout instead of setInterval...
<script type="text/javascript">
var show;
var done = false;
show = setTimeout(showHideForm, 3500);
function showHideForm() {
// Do something
if(done) {
clearTimeout(show);
show = setTimeout(showHideForm, 2000);
}
}
</script>
clearTimeout takes as argument the handle which is returned by setTimeout.
Use a named function and call it when you want.
var loop = setInterval(loopFunc, 3500);
function loopFunc(){
//do something
}
function anticipate(){
clearInterval(loop); //Stop interval
loopFunc(); //Call your function
loop = setInterval(loopFunc, 3500); //Reset the interval if you want
}
My contrived example:
var time = 3500,
loops = 0,
loop;
(function run(){
var wait = time,
dontwait = false;
if (loops++ == 5) {
loops = 0;
dontwait = 1000;
}
console.log('Interval: ', dontwait || wait);
return loop = setTimeout(run, dontwait || wait);
})();
http://jsfiddle.net/NX43d/1/
Basically, a self-invoking function looping back on a self-calling function, with (!) shorthand variable switching. Nifty.
function looper(t) {
var loop = setInterval(function() {
document.write(s++);
if (mycondition) { // here is your condition
loopagain(200); // specify the time which new loop will do
loop = window.clearInterval(loop); // clear the first interval
return; // exit from this function!
}
}, t);
}
window.onload = looper(1000); // this will have default setInterval function time ans will start at window load!
function loopagain(t) {
looper(t);
}
http://jsfiddle.net/tFCZP/
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);