Stop for loop with a function inside in react - javascript

i have this use effect that every time stopBet is true it runs the script, basically it gets the total amount of times that the process must be done and it does correctly, but i want to be able to stop it in any moment with a button, but i dont know how to handle it
useEffect(() => {
if(stopBet) {
if(numberBets > 0){
for (let i=0; i<numberBets; i++) {
task(i);
}
function task(i) {
setTimeout(function() {
console.log(i, 'bet');
const stopAt = numberBets-1;
console.log(stopAt);
if (i === stopAt){
Submit()
setLoading(false)
}else{
try {
Submit()
} catch (error) {
console.log(error);
}
}
}, 2000 * i);
};
} else {
for (let i=0; i<99999; i++) {
task(i);
};
function task(i) {
setTimeout(function() {
console.log(i, 'bet');
try {
Submit()
} catch (error) {
console.log(error);
}
}, 2000 * i);
};
};
}
}, [stopBet]);
maybe there is a better way of doing this without a for loop but i havent figure it out, im still a newbie in react, so any advice would be appreciated
Update
So i did this code using the set interval property
useEffect(() => {
console.log(stopBet);
let interval = null;
if(stopBet){
interval = setInterval(()=>{
for (let i=0; i<numberBets; i++) {
if(i === numberBets){
setStopBet(false)
}else{
Submit()
}
}
},3000)
}else{
clearInterval(interval)
}
return () => clearInterval(interval)
}, [stopBet]);
but now the issue is that passed the 3 seconds this makes the submit function the times that i inserted throught the input, i dont know if my implementation of the for loop is the indicated for this

Related

Place parts of a for loop into function in javascript

I have several functions that use this given for loop below.
function startClaw(dir){
var readCount = 0;
for(var isRead in qdata){
readCount++;
if(qdata[isRead]['reading'] == true){
return;
}else if(readCount == 5){
isAnimating = $("#claw").is(':animated');
if(!isAnimating){// prevents multiple clicks during animation
if(isMoving || isDropping){ return; }
MCI = setInterval(function(){ moveClaw(dir); },10);
//console.log("startClaw:" + dir);
stopSwingClaw();
}
}
}
}
//.................................................................
function dropClaw(){
var readCount = 0;
for(var isRead in qdata){
readCount++;
if(qdata[isRead]['reading'] == true){
return;
}else if(readCount == 5){
if(isDropping){ return; } //prevent multiple clicks
stopSwingClaw();
isDropping = true;
MCI = setInterval(moveDown,20); //start heartbeat
}
}
}
Everything in the else if statement is different within the various functions. I'm wondering if there is any way to place the "pieces" of the for loop on the outside of the else if into its very own function. I feel like I've seen this or had done this a very long time ago, but it escapes me and I couldn't find any examples. Thanks everyone!
Previewing, I see this is similar to the above. Two differences (it looks like) are here the count gets passed to the function in case they needed to ever have different checks in the if statement, and, it's checking what the return value is since it looks like you return out of the loop if the condition is met. There are notes in comments in the code below.
function startClaw(dir) {
// Pass a function as a callback to the method which expects to receive the count as a param
doReadCount(qdata, function(theCount) {
if (theCount === 5) {
isAnimating = $("#claw").is(':animated');
if (!isAnimating) { // prevents multiple clicks during animation
if (isMoving || isDropping) {
return true;
}
MCI = setInterval(function() { moveClaw(dir); }, 10);
//console.log("startClaw:" + dir);
stopSwingClaw();
}
return false;
});
}
//.................................................................
function dropClaw() {
// Pass a function as a callback to the method which expects to receive the count as a param
doReadCount(qdata, function(theCount) {
if (theCount === 5) {
if (isDropping) {
return;
} //prevent multiple clicks
stopSwingClaw();
isDropping = true;
MCI = setInterval(moveDown,20); //start heartbeat
}
});
}
function doReadCount(qdata, elseFunction) {
var readCount = 0;
var elseReturn;
for (var isRead in qdata) {
readCount++;
if (qdata[isRead]['reading'] == true) {
return;
} else {
// call the function that was sent and pass it the current read count. If the return is true, then also return true here
elseReturn = elseFunction(readCount);
if (elseReturn) {
return;
}
}
}
}
You can pass a function into another function to achieve this. I've done it for dropClaw, and it should be clear from my example how to do also extract startClaw.
function operateClaw(func){
var readCount = 0;
for(var isRead in qdata){
readCount++;
if(qdata[isRead]['reading'] == true){
return;
}else if(readCount == 5){
func();
}
}
}
function drop () {
if(isDropping){ return; } //prevent multiple clicks
stopSwingClaw();
isDropping = true;
MCI = setInterval(moveDown,20); //start heartbeat
}
function dropClaw () {
operateClaw(drop);
}

how to use setTimeout or setInterval properly

I am using google maps and i am trying to put a pause in execution to prevent QUERY_LIMIT usage issue. My function that plots the addresses looks like this.
The code works, however i want to try setTimeout or setInterval to see if its going to look better on UI.
How do i call it, what should be the first argument?
Thanx alot.
vLocations = [];
for (var i = 0; i < vAddresses.length; i++) {
//pause to prevent OVER_QUERY_LIMIT issue
//geocode "free" usage limit is 5 requests per second
//setTimeout(PlotAddressesAsUnAssigned, 1000);
//sleep(500);
//this will resolve the address and store it in vLocations
AddWaypointAndUnassigned(vAddresses[i]);
var z = i % 4;
if (z==0 && i != 0) {
//sleep after every 5th geocode call
//alert('going to sleep...i: ' + i);
//sleep(3000);
}
}
Doing a pause (asynchronous execution) inside a loop (synchronous) will usually result in a lot of trouble.
You can use recursive calls that are done only when a timeout ends.
var vLocations = [];
// Manages the timeout and recursive calls
function AddWaypointAndUnassignedWithPause(index){
setTimeout(function(){
// When the timeout expires, we process the data, and start the next timeout
AddWaypointAndUnassigned(vAddresses[index]);
// Some other code you want to execute
var z = i % 4;
if (z==0 && i != 0) {
//sleep after every 5th geocode call
//alert('going to sleep...i: ' + i);
//sleep(3000);
}
if(index < vAddresses.length-1)
AddWaypointAndUnassignedWithPause(++index);
}, 1000);
}
// Start the loop
AddWaypointAndUnassignedWithPause(0);
JSFiddle example.
Try this, hope this will help
vLocations = [];
for (var i = 0; i < vAddresses.length; i++) {
//pause to prevent OVER_QUERY_LIMIT issue
setTimeout(function(){
//this will resolve the address and store it in vLocations
AddWaypointAndUnassigned(vAddresses[i]);
}, 500);
var z = i % 4;
if (z==0 && i != 0) {
//sleep after every 5th geocode call
//alert('going to sleep...i: ' + i);
//sleep(3000);
}
}
What about a waiting line, thats fired when an item is added and stopped when there are no items left.
With setTimeout:
var INTERVAL = 1000 / 5;
var to = null;
var vLocations = [];
function addAddress(vAddress) {
vLocations.push(vAddress);
startTimeout();
}
function startTimeout() {
if( to === null ) {
to = setTimout(processLocation, INTERVAL);
}
}
function processLocation() {
if( vLocations.length ) {
var vAddress = vLocations.shift();
AddWaypointAndUnassigned(vAddress);
to = setTimout(processLocation, INTERVAL);
} else {
to = null;
}
}
With setInterval:
var INTERVAL = 1000 / 5;
var to = null;
var vLocations = [];
function addAddress(vAddress) {
vLocations.push(vAddress);
startInterval();
}
function startInterval() {
if( to === null ) {
to = setInterval(processLocation, INTERVAL);
}
}
function processLocation(cb) {
if( vLocations.length ) {
var vAddress = vLocations.shift();
AddWaypointAndUnassigned(vAddress);
} else
clearInterval(to);
to = null;
}
}

fade in and out loop with three divs in javascript

I've used this
http://jsfiddle.net/3KydB/
and tried to modify it for 3 divs:
window.switchIn = function () {
$('.chart_1').fadeToggle(function() {
$('.chart_2').fadeToggle(function() {
$('.chart_3').fadeToggle(function() {
setTimeout(function() {window.switchOut();}, 6000);
});
});
});
}
window.switchOut = function () {
$('.chart_3').fadeToggle(function() {
$('.chart_2').fadeToggle(function() {
$('.chart_1').fadeToggle(function() {
setTimeout(function() {window.switchIn();}, 6000);
});
});
});
}
setTimeout(function() {window.switchIn();}, 6000)
The first one fades in and out fine, then the second one fades in with the third one below it, then back to the first one etc.
I think you would want something like the following: http://jsfiddle.net/mEeAt/
window.switch1 = function () {
$('.chart_3').fadeToggle(function() {
$('.chart_1').fadeToggle(function() {
setTimeout(window.switch2, 6000);
});
});
}
window.switch2 = function () {
$('.chart_1').fadeToggle(function() {
$('.chart_2').fadeToggle(function() {
setTimeout(window.switch3, 6000);
});
});
}
window.switch3 = function () {
$('.chart_2').fadeToggle(function() {
$('.chart_3').fadeToggle(function() {
setTimeout(window.switch1, 6000);
});
});
}
setTimeout(window.switch2, 6000)
So each function is responsible for fading out the active element, fading in the next element, and setting a timeout for the next function in the cycle.
Of course there is a lot of repeated code here, so you would probably be better off creating a function to make this more generic: http://jsfiddle.net/mEeAt/1/
function cycle(delay) {
var elements = Array.prototype.slice.call(arguments, 1);
var functions = [];
for (var i = 0; i < elements.length; i++) {
functions.push(function (i) {
var prev = i === 0 ? elements.length - 1 : i - 1;
var next = (i + 1) % elements.length;
return function() {
elements[prev].fadeToggle(function() {
elements[i].fadeToggle(function() {
setTimeout(functions[next], delay);
});
});
};
}(i));
}
functions[1](); // start cycle by fading in the second element
}
cycle(6000, $('.chart_1'), $('.chart_2'), $('.chart_3'));

How do I update the html displayed for each iteration of a for loop in javascript / jquery?

How would I have the h1 change for each iteration of the loop? This code now only displays the h1 text after everything is done.
for (i=0; i<array.length; i++) {
$("body > h1").text("Processing #" + i);
// things that take a while to do
}
Additional info: if I resize the window as it loops, the html updates.
var array = ['one', 'two', 'three']
var i = 0;
var refreshIntervalId = setInterval(function() {
length = array.length;
if (i < (array.length +1)) {
$("h1").text("Processing #" + i);
} else {
clearInterval(refreshIntervalId);
}
i++
}, 1000);
http://jsfiddle.net/3fj9E/
Use a setInterval with a one-millisecond delay:
var i=0, j=array.length;
var iv = setInterval(function() {
$("h1").text("Processing #" + i);
// things that take a while to do
if (++i>=j) clearInterval(iv);
}, 1);
http://jsfiddle.net/mblase75/sP9p7/
Sometimes you can force a render by forcing a recalculation of layout
for (i=0; i<array.length; i++) {
$("body > h1").text("Processing #" + i)
.width(); // force browser to recalculate layout
// things that take a while to do
}
It might not work in all browsers.
A better way, that does not block the browser so much:
function doThings(array) {
var queueWork,
i = -1,
work = function () {
// do work for array[i]
// ...
queueWork();
};
queueWork = function () {
if (++i < array.length) {
$("body > h1").text("Processing #" + i);
setTimeout(work, 0); // yield to browser
}
};
}
doThings(yourArray);
DEMO
I've spent a bit of time working out a jquery function that seems to solve this. Basically, it's a process handler that you can add any number of processes to and then call run to sequentially call these in a asynchronous way.
$.fn.LongProcess = function () {
var _this = this;
this.notifications = [];
this.actions = [];
this.add = function (_notification, _action) {
this.notifications.push(_notification);
this.actions.push(_action);
};
this.run = function () {
if (!_this.actions && !_this.notifications) {
return "Empty";
}
//******************************************************************
//This section makes the actions lag one step behind the notifications.
var notification = null;
if (_this.notifications.length > 0) notification = _this.notifications.shift();
var action = null;
if ((_this.actions.length >= _this.notifications.length + 2) || (_this.actions.length > 0 && _this.notifications.length == 0))
action = _this.actions.shift();
//****************************************************************
if (!action && !notification) {
return "Completed";
}
if (action) action();
if (notification) notification();
setTimeout(_this.run, 1000);
//setTimeout(_this.run,1); //set to 1 after you've entered your actual long running process. The 1000 is there to just show the delay.
}
return this;
};
How to use with <h1 class="processStatus"></h1>:
$(function () {
var process = $().LongProcess();
//process.add(notification function, action function);
process.add(function () {
$(".processStatus").text("process1");
}, function () {
//..long process stuff
alert("long process 1");
});
process.add(function () {
$(".processStatus").text("process2");
}, function () {
//..long process stuff
alert("long process 2");
});
process.add(function () {
$(".processStatus").text("process3");
}, function () {
//..long process stuff
alert("long process 3");
});
process.run();
});
if the process is very long you can use this script which shows every notification for a specific time interval.
here is the code..
html
<div id="ccNotificationBox"></div>
css
#ccNotificationBox{
-webkit-animation-name:;
-webkit-animation-duration:2s;/*Notification duration*/
box-sizing:border-box;
border-radius:16px;
padding:16px;
background-color:rgba(0,0,0,0.7);
top:-100%;
right:16px;
position:fixed;
color:#fff;
}
#ccNotificationBox.active{
-webkit-animation-name:note;
top:16px;
}
#-webkit-keyframes note{
0% {opacity:0;}
20% {opacity:1;}
80% {opacity:1;}
100% {opacity:0;}
}
javascript
var coccoNotification=(function(){
var
nA=[],
nB,
rdy=true;
function nP(a){
nA.push(a);
!rdy||(nR(),rdy=false);
}
function nR(){
nB.innerHTML=nA[0];console.log(nA[0]);
nB.offsetWidth=nB.offsetWidth;//reflow ios
nB.classList.add('active');
}
function nC(){
nB.classList.remove('active');
nB.innerHTML='';
nA.shift();
nA.length>0?nR():(rdy=true);
}
function init(){
nB=document.getElementById('ccNotificationBox');
nB.addEventListener('webkitAnimationEnd',nC,false);
window.removeEventListener('load',init,false);
}
window.addEventListener('load',init,false);
return nP
})();
usage
coccoNotification('notification 1');
example
http://jsfiddle.net/f6dkE/1/
info
the example above is perfect for external js as you use just one global variable which is the name of the function ... in my case coccoNotification
here is a different approach but it does the same
http://jsfiddle.net/ZXL4q/11/

Wait until a condition is true?

I'm using navigator.geolocation.watchPosition in JavaScript, and I want a way to deal with the possibility that the user might submit a form relying on location before watchPosition has found its location.
Ideally the user would see a 'Waiting for location' message periodically until the location was obtained, then the form would submit.
However, I'm not sure how to implement this in JavaScript given its lack of a wait function.
Current code:
var current_latlng = null;
function gpsSuccess(pos){
//console.log('gpsSuccess');
if (pos.coords) {
lat = pos.coords.latitude;
lng = pos.coords.longitude;
}
else {
lat = pos.latitude;
lng = pos.longitude;
}
current_latlng = new google.maps.LatLng(lat, lng);
}
watchId = navigator.geolocation.watchPosition(gpsSuccess,
gpsFail, {timeout:5000, maximumAge: 300000});
$('#route-form').submit(function(event) {
// User submits form, we need their location...
while(current_location==null) {
toastMessage('Waiting for your location...');
wait(500); // What should I use instead?
}
// Continue with location found...
});
Modern solution using Promise
function waitFor(conditionFunction) {
const poll = resolve => {
if(conditionFunction()) resolve();
else setTimeout(_ => poll(resolve), 400);
}
return new Promise(poll);
}
Usage
waitFor(_ => flag === true)
.then(_ => console.log('the wait is over!'));
or
async function demo() {
await waitFor(_ => flag === true);
console.log('the wait is over!');
}
References
Promises
Arrow Functions
Async/Await
Personally, I use a waitfor() function which encapsulates a setTimeout():
//**********************************************************************
// function waitfor - Wait until a condition is met
//
// Needed parameters:
// test: function that returns a value
// expectedValue: the value of the test function we are waiting for
// msec: delay between the calls to test
// callback: function to execute when the condition is met
// Parameters for debugging:
// count: used to count the loops
// source: a string to specify an ID, a message, etc
//**********************************************************************
function waitfor(test, expectedValue, msec, count, source, callback) {
// Check if condition met. If not, re-check later (msec).
while (test() !== expectedValue) {
count++;
setTimeout(function() {
waitfor(test, expectedValue, msec, count, source, callback);
}, msec);
return;
}
// Condition finally met. callback() can be executed.
console.log(source + ': ' + test() + ', expected: ' + expectedValue + ', ' + count + ' loops.');
callback();
}
I use my waitfor() function in the following way:
var _TIMEOUT = 50; // waitfor test rate [msec]
var bBusy = true; // Busy flag (will be changed somewhere else in the code)
...
// Test a flag
function _isBusy() {
return bBusy;
}
...
// Wait until idle (busy must be false)
waitfor(_isBusy, false, _TIMEOUT, 0, 'play->busy false', function() {
alert('The show can resume !');
});
This is precisely what promises were invented and implemented (since OP asked his question) for.
See all of the various implementations, eg promisejs.org
You'll want to use setTimeout:
function checkAndSubmit(form) {
var location = getLocation();
if (!location) {
setTimeout(checkAndSubmit, 500, form); // setTimeout(func, timeMS, params...)
} else {
// Set location on form here if it isn't in getLocation()
form.submit();
}
}
... where getLocation looks up your location.
You could use a timeout to try to re-submit the form:
$('#route-form').submit(function(event) {
// User submits form, we need their location...
if(current_location==null) {
toastMessage('Waiting for your location...');
setTimeout(function(){ $('#route-form').submit(); }, 500); // Try to submit form after timeout
return false;
} else {
// Continue with location found...
}
});
export default (condition: Function, interval = 1000) =>
new Promise((resolve) => {
const runner = () => {
const timeout = setTimeout(runner, interval);
if (condition()) {
clearTimeout(timeout);
resolve(undefined);
return;
}
};
runner();
});
class App extends React.Component {
componentDidMount() {
this.processToken();
}
processToken = () => {
try {
const params = querySearch(this.props.location.search);
if('accessToken' in params){
this.setOrderContext(params);
this.props.history.push(`/myinfo`);
}
} catch(ex) {
console.log(ex);
}
}
setOrderContext (params){
//this action calls a reducer and put the token in session storage
this.props.userActions.processUserToken({data: {accessToken:params.accessToken}});
}
render() {
return (
<Switch>
//myinfo component needs accessToken to retrieve my info
<Route path="/myInfo" component={InofUI.App} />
</Switch>
);
}
And then inside InofUI.App
componentDidMount() {
this.retrieveMyInfo();
}
retrieveMyInfo = async () => {
await this.untilTokenIsSet();
const { location, history } = this.props;
this.props.processUser(location, history);
}
untilTokenIsSet= () => {
const poll = (resolve) => {
const { user } = this.props;
const { accessToken } = user;
console.log('getting accessToken', accessToken);
if (accessToken) {
resolve();
} else {
console.log('wating for token .. ');
setTimeout(() => poll(resolve), 100);
}
};
return new Promise(poll);
}
Try using setInterval and clearInterval like this...
var current_latlng = null;
function gpsSuccess(pos) {
//console.log('gpsSuccess');
if (pos.coords) {
lat = pos.coords.latitude;
lng = pos.coords.longitude;
} else {
lat = pos.latitude;
lng = pos.longitude;
}
current_latlng = new google.maps.LatLng(lat, lng);
}
watchId = navigator.geolocation.watchPosition(gpsSuccess,
gpsFail, {
timeout: 5000,
maximumAge: 300000
});
$('#route-form').submit(function (event) {
// User submits form, we need their location...
// Checks status every half-second
var watch = setInterval(task, 500)
function task() {
if (current_latlng != null) {
clearInterval(watch)
watch = false
return callback()
} else {
toastMessage('Waiting for your location...');
}
}
function callback() {
// Continue on with location found...
}
});
This accepts any function, even if it's async, and when it evaluates to a truthy value (checking every quarter-second by default), resolves to it.
function waitFor(condition, step = 250, timeout = Infinity) {
return new Promise((resolve, reject) => {
const now = Date.now();
let running = false;
const interval = setInterval(async () => {
if (running) return;
running = true;
const result = await condition();
if (result) {
clearInterval(interval);
resolve(result);
} else if (Date.now() - now >= timeout * 1000) {
clearInterval(interval);
reject(result);
}
running = false;
}, step);
});
}
Example
example();
async function example() {
let foo = 'bar';
setTimeout(() => foo = null, 2000);
console.log(`foo === "${foo}"`);
await waitFor(() => foo === null);
console.log('2 seconds have elapsed.');
console.log(`foo === ${foo}`);
}
function waitFor(condition, step = 250, timeout = Infinity) {
return new Promise((resolve, reject) => {
const now = Date.now();
let running = false;
const interval = setInterval(async () => {
if (running) return;
running = true;
const result = await condition();
if (result) {
clearInterval(interval);
resolve(result);
} else if (Date.now() - now >= timeout * 1000) {
clearInterval(interval);
reject(result);
}
running = false;
}, step);
});
}

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