i have a function, which should return TRUE, when IF condition inside FOR cyklus is met. (i tested that condition, it works)
createBtn.addEventListener('click',function (e){
var ch = function check(){
var url = "http://hotel.010.sk/skyfit/read.php";
var json, poc, vypis;
var i=0;
var xhr = Ti.Network.createHTTPClient({
onload: function() {
json = JSON.parse(this.responseText);
for (i = 0; i < json.poc.length; i++) {
prnt = json.poc[i];
if(win.xtra_id == prnt.id_cv && picker.getSelectedRow(0).title == prnt.datum && prnt.capacity <= prnt.cnt ){
return true;
}
};
}
});
xhr.open("GET", url);
xhr.send();
};
...
But when i call function here to check it turns me always true, unless IF condition in check() is not met!
if(ch){
alert('Something');
}
How to fix my function to get TRUE only when my condition is met?
Thanks.
This expression
if (ch) {
is always true, because ch is a function and ToBoolean(function) === true.
However even if you changed it to if (ch()) {..} it would not work anyway, because inside of the function you perform asynchronous operation. Function just returns without waiting for it to finish. In this case you should use callbacks or promise patters. Simplest is callback.
var ch = function check(callback) {
// ...
var xhr = Ti.Network.createHTTPClient({
onload: function () {
json = JSON.parse(this.responseText);
var status = false;
for (i = 0; i < json.poc.length; i++) {
prnt = json.poc[i];
if (win.xtra_id == prnt.id_cv && picker.getSelectedRow(0).title == prnt.datum && prnt.capacity <= prnt.cnt) {
status = true;
}
};
callback(status);
}
});
// ...
};
ch(function(status) {
if (status) {
alert('Something')
}
});
Please try with following thing to check condition should always true
while(true){
alert('something');
}
Your function, ch has no return value! It launches the Ti.Network.createHTTPClient function where you define an anonymous callback function (onload: function(){...). That anonymous function is executed after the ch has already returned. You'll need to either check your conditional after the callback:
...
if (win.xtra_id == prnt.id_cv && picker.getSelectedRow(0).title == prnt.datum && prnt.capacity <= prnt.cnt) {
alert('something') //DO YOUR STUFF HERE!
return true;
}
...
or wait for the callback to happen before you check the conditional using some global flags:
var MYFLAG=-1
...
if (win.xtra_id == prnt.id_cv && picker.getSelectedRow(0).title == prnt.datum && prnt.capacity <= prnt.cnt) {
MYFLAG=1
return true;
}
else
{
MYFLAG=0
}
...
//use a timer to check the flag every 500ms
var myInterval = setInterval(function()
{
if (MYFLAG != -1) {
if (MYFLAG==1) {
alert('returned true :)');
}
else {
alert('did not return true :(');
}
clearInterval(myInterval);
}
}, 500);
Related
I have a onMouseDownEssence() and onMouseUpEssence() function for an HTML element, how to check if onMouseDownEssence() is called every time before calling onMouseUpEssence() to ensure I get the correct mouse down position?
Here is mousedown function:
var mouseDownIndex = -1;
function onMouseDownEssence(downIndex, e, className) {
dragTarget = e.target;
holdStarter = new Date().valueOf();
mouseDownIndex = downIndex;
}
Here is mouseup function:
function onMouseUpEssence(upIndex, e, className) {
var el = e.target;
var holdActive = (new Date().valueOf() - holdStarter) > holdDelay;
if (holdActive) {
var thisUpTargetIndex = el.getAttribute("name");
if (lastUpTargetIndex != null && thisUpTargetIndex != lastUpTargetIndex) {
// console.log("double drag done");
el.removeAttribute(dbl);
lastUpTargetIndex = null;
var selectedText = clickDragAutoExpand(mouseDownIndex, upIndex,
className);
} else {
// console.log("drag done");
var selectedText = clickDragAutoExpand(mouseDownIndex, upIndex,
className);
}
holdActive = false;
} else if (el.getAttribute(dbl) == null) {
el.setAttribute(dbl, 1);
setTimeout(
function() {
if (el.getAttribute(dbl) == 1 && !dragTarget) {
if (e.button === 0) {
// console.log("single clicked ");
el.removeAttribute(dbl);
var selectedText = clickAutoExpand(upIndex,
className);
}
} else {
if (el.getAttribute(dbl) != null)
lastUpTargetIndex = el.getAttribute("name");
}
}, dblDelay);
} else {
// console.log("double clicked");
el.removeAttribute(dbl);
var selectedText = clickAutoExpand(upIndex, className);
}
dragTarget = null;
}
My approach would be to keep a track of whether mouseDownEssence() was called. And if not, call it before proceeding further. This approach would work somewhat as below. It would work differently for asynchronous functions but mouseDownEssence() seems to be a synchronous function.
let isMouseDownEssenceCalled = false;
function mouseDownEssence() {
isMouseDownEssenceCalled = true;
...
}
function mouseUpEssence() {
if (!isMouseDownEssenceCalled) {
mouseDownEssence()
}
...
isMouseDownEssenceCalled = false;
}
I am having some problem using the settimeout() in my function. I am new to async. No matter how much I try I just can't make the timeout work. My code works perfect so that is not the problem. I need the request to execute every 10 seconds. Thanks for the help.
function getContent() {
function getPelicula(pelicula, donePelicula) {
var peli = pelicula.title;
//request id
request({
url: "http://api.themoviedb.org/3/search/movie?query=" + peli + "&api_key=3e2709c4c051b07326f1080b90e283b4&language=en=ES&page=1&include_adult=false",
method: "GET",
json: true,
}, function(error, res, body) {
if (error) {
console.error('Error getPelicula: ', error);
return;
}
var control = body.results.length;
if (control > 0) {
var year_base = pelicula.launch_year;
var id = body.results[0].id;
var year = body.results[0].release_date;
var d = new Date(year);
var year_solo = d.getFullYear();
if (year_base == year_solo) {
pelicula.id = id;
pelicula.year_pagina = year_solo;
}
} else {
pelicula.id = null;
pelicula.year_pagina = null;
}
donePelicula();
});
}
}
To do something in a loop, use setInterval.
UPD:
In general, there're two ways of executing some code in loop
1 setTimeout :
var someTimer = setTimeout(function sayHello(){
console.log("hello!");
someTimer = setTimeout(sayHello, 2000);
}, 2000);
Notice that someTimer variable is needed to stop the looping process if you need: clearTimeout(someTimer)
2 setInterval:
var someIntervalTimer = setInterval(function(){
console.log("I'm triggered by setInterval function!");
}, 2000);
Invoke clearInterval(someIntervalTimer) to stop the looping
Both functions are treated as properties of the global Window variable. By default, the following code works:
var window = this;
console.log("type of setTimeout: " + typeof window.setTimeout);
console.log("type of setInterval: " + typeof window.setInterval);
Try putting it in another function so:
domore(pelicula,donePelicula);
function domore(pelicula,donePelicula) {
// 1 second
var timeout = 1000;
for (var i = 1; i < pelicula.length; i++) {
createData(pelicula[i],donePelicula,timeout);
timeout = timeout + 800;
}
}
function createData(peli,donePelicula,timeout) {
setTimeout(function() { getData(peli,donePelicula); }, timeout);
}
function getData(peli,donePelicula) {
var txtFile = new XMLHttpRequest();
txtFile.open("GET", "http://api.themoviedb.org/3/search/movie?query=" + peli + "&api_key=3e2709c4c051b07326f1080b90e283b4&language=en=ES&page=1&include_adult=false", true);
txtFile.onreadystatechange = function() {
if (txtFile.readyState === 4) { // Makes sure the document is ready to parse.
if (txtFile.status === 200) { // Makes sure it's found the file.
allText = txtFile.responseText;
domore(allText,donePelicula);
}
}
}
txtFile.send(null);
}
Im having trouble getting my second function to react to the changes the first function brings.
var jumbotron = function(){
var jumbotronCounter = 1
var jumbotronSwitch = function(){
var jumbotronTimer = function(){
jumbotronCounter++
}
jumbotronTimer();
if (jumbotronCounter > 3){
jumbotronCounter = 1
}
console.log(jumbotronCounter);
}
setInterval(jumbotronSwitch,7000);
var jumbotronListener = function(){
if(jumbotronCounter = 1){
console.log('first');
}else if(jumbotronCounter = 2){
console.log('second');
}else if(jumbotronCounter = 3){
console.log('third');
}
};
jumbotronListener();
}
jumbotron();
Id like to use "jumbotronListener" to run some code when "jumbotronCounter" changes
jumbotronListener is indeed only running once. You can, instead, run it every time the interval runs:
var jumbotron = function () {
var jumbotronCounter = 1;
var jumbotronSwitch = function () {
var jumbotronTimer = function () {
jumbotronCounter++;
};
jumbotronTimer();
if (jumbotronCounter > 3) {
jumbotronCounter = 1;
}
// Execute the listener every time the interval runs
jumbotronListener();
console.log(jumbotronCounter);
};
setInterval(jumbotronSwitch, 7000);
// Run for the first time if you wish:
jumbotronListener();
// Set this as function so you can 'use it before declaring it'
function jumbotronListener() {
// You had invalid operators. = assigns and === compares (strictly)
if(jumbotronCounter === 1) {
console.log('first');
} else if(jumbotronCounter === 2) {
console.log('second');
} else if(jumbotronCounter === 3) {
console.log('third');
}
}
};
jumbotron();
You also had some missing semicolons in there, sometimes it's not a problem since JavaScript auto-inserts them, but sometimes it is, so it's a good idea to always make sure to manually insert them where they go.
I'm trying to break a for-loop (labeled) from within a nested anonymous function, like this:
function ajax(iteration, callback) {
var rtrn, xh;
if (window.XMLHttpRequest) {
xh = new XMLHttpRequest();
} else {
xh = new ActiveXObject("Microsoft.XMLHTTP");
};
xh.onreadystatechange = function() {
if (xh.readyState == 4 && xh.status == 200) {
callback(xh.responseText);
};
};
xh.open("GET", "file.php?i=" + iteration, true);
xh.send();
};
var atk_delay = 100;
loop:
for(i = 1; i <= 40; i++) {
var to = atk_delay * i;
setTimeout(
function() {
ajax(i, function(responseText) {
var div = document.getElementById("combat");
div.innerHTML += responseText;
var arrRt = responseText.split("::");
if(arrRt[0] == "stop") {
break loop;
};
});
},
to);
};
I really have no idea how to solve this. Obviously, the problem is that it cannot find the label. How can I resolve this?
So I solved it! Thanks for the help guys! You got me to realize I needed a completely different approach!
function ajax(callback) {
var rtrn, xh;
if (window.XMLHttpRequest) {
xh = new XMLHttpRequest();
} else {
xh = new ActiveXObject("Microsoft.XMLHTTP");
};
xh.onreadystatechange = function() {
if (xh.readyState == 4 && xh.status == 200) {
callback(xh.responseText);
};
};
xh.open("GET", "file.php", true);
xh.send();
};
var atk_delay = 100;
function roll() {
ajax(function(responseText) {
var div = document.getElementById("combat");
div.innerHTML += responseText;
var arrRt = responseText.split("::");
if(arrRt[0] == "cont") {
setTimeout(roll, atk_delay);
};
});
};
setTimeout(roll, atk_delay);
Normally what you would do is have a variable that's accessible after each iteration of the loop that would indicate if you can break. This would be set in the anonymous function.
However, in your specific case, since you are calling setTimeout, execution of the loop might have been completed by the time you can even set the value. setTimeout schedules the function to later execution (in ms).
You can use a variable to exit the anonymous function early if something has flagged it as done.
A simple hack to debug anonymous blocks - call the debugger explicitly before the line you want to examine.
function foo().then(s => {
... some code
debugger // here your code will break.
someVariableIwantToExamine
}
So I'm running some animations to bring in some divs in my first jQuery plugin:
$.fn.turnstile = function (options, callback) {
if (!this.length) {
return this;
}
count = this.length;
var opts = $.extend(true, {}, $.fn.turnstile.defaults, options)
var delayIt = 100;
if (opts.direction == "in") {
opts.deg = '0deg';
opts.trans = '0,0';
opts.opacity = 1;
} else if (opts.direction == "out") {
opts.deg = '-90deg';
opts.trans = "-100px, 200px";
opts.opacity = 0;
} else if (opts.direction == "back") {
opts.deg = '0deg';
opts.trans = '-2000px,0px';
opts.opacity = 0;
} else {
opts.deg = direction;
}
this.each(function (index) {
delayIt += opts.delayer;
$(this).show().delay(delayIt).transition({
perspective: '0px',
rotateY: opts.deg,
opacity: opts.opacity,
translate: opts.trans
}, 400, 'cubic-bezier(0.33,0.66,0.66,1)', function () {
if (opts.direction == "back" || opts.direction == "out") {
$(this).hide();
}
if (!--count && callback && typeof (callback) === "function") {
if ($(":animated").length === 0) {
callback.call(this);
}
}
});
});
return this;
};
Now, I'd like to call my callback when all animations are completed, which should mathematically be (delayIt+400)*count - but I can't get the callback to run when all of the animations are complete. As you might be able to tell from its current state, I've attempted to check for :animated, used the !--count condition, and even tried setting a timeout equal to the duration of the animations, but all seem to fire asynchronously. What is the best way to animate these and call something back when done?
Here's the info on the .transition() plugin.
Not tested with your code (i'm not familiar with .transition), but try this:
...
this.promise().done(function(){
alert('all done');
});
return this;
};