I've found a lot of questions about deferring, promises, running javascript synchronously, etc. and I've tried numerous things already but still can't get this to work.
Edit Here's a little more explanation on the problem. fetchData has a routine that depends on all the code inside showStuff being complete. In particular, there's divs that get created using percentage of screen size, and we need to get the height of those divs so we can draw gauges inside them. fetchData is running before slideDown() is complete. Please see the additional console.log code I've added directly below.
My button onClick() calls showOverlay().
function showOverlay() {
showStuff().promise().done( function() {
console.log($("#gauge1").height()); //returns -0.5625 or something close
fetchData(); //ajax call
});
}
function showStuff() {
$("#overlay").fadeIn(200);
$("#gauges").slideDown(800);
$(".gauge").each(function() {
$( this ).show(); //unhides #gauge1 div
});
}
The error I'm getting says: cannot call method 'promise' of undefined.
I'm not showing my fetchData() function but it basically uses ajax to call a web service and then creates gauges on the screen using Raphael. If fetchData runs before the animations are complete the gauges are not displayed correctly because their size is relative to the .gauge div's.
Edit1
Neither of the examples below work. They both run without errors but return too quickly.
function showOverlay() {
showStuff().promise().done(function() {
fetchData();
});
}
function showStuff() {
var def = $.Deferred();
$("#overlay").fadeIn(200);
$("#gauges").slideDown(800);
$(".gauge").each(function() {
$( this ).show();
});
def.resolve();
return def;
}
Doesn't work either:
function showOverlay() {
$.when(showStuff()).done(function() {
fetchData();
});
}
function showStuff() {
$("#overlay").fadeIn(200);
$("#gauges").slideDown(800);
$(".gauge").each(function() {
$( this ).show();
});
}
You've 2 issues, the deferred and thats not how you run animations one after the other.
This will get you part of the way:
function showStuff() {
var deferred = $.Deferred();
$("#overlay").fadeIn(300,function(){
$("#gauges").slideDown(800,function(){
$(".gauge").show(); //doing this one after another takes more code.
deferred.resolve();
});
});
return deferred;
}
Heres the codepen: http://codepen.io/krismeister/pen/pvgKj
If you need to do sophisticated animations like this. You might find better results with GSAP.
Heres how to stagger:
http://www.greensock.com/jump-start-js/#stagger
Try to use $.when() instead:
$.when(showStuff()).done(function() {
fetchData();
});
You a) need to return something from showStuff b) should return a promise directly, so that the .promise() method is unnecessary:
function showOverlay() {
showStuff().done(function() {
fetchData();
});
}
function showStuff() {
return $("#overlay").fadeIn(200).promise().then(function() {
return $("#gauges").slideDown(800).promise();
}).then(function() {
return $(".gauge").show().promise();
});
}
Related
I have a testimonial scroller that shows one testimonial, fades out, shows the next, fades out, and returns to the first.
My issue is that after the fade in animation, the fade out animation begins immediately. It doesn't give enough time for someone to read it.
$(document).ready(function() {
function doFade() {
$("#one").fadeIn(6000,function() {
$("#one").fadeOut(6000).delay(3000);
setTimeout(fadeTwo,6000);
});
}
function fadeTwo() {
$("#two").fadeIn(6000,function() {
$("#two").fadeOut(6000).delay(3000);
setTimeout(fadeThree,6000);
});
}
function fadeThree() {
$("#three").fadeIn(4000,function() {
$("#three").fadeOut(6000).delay(3000);
setTimeout(doFade,6000);
});
}
doFade();
});
jQuery's delay function will only delay functions that are called after it in the chain, so it is having no effect on your code. Delay docs
You need to use it before the call to fadeOut, e.g.
$(document).ready(function() {
function doFade() {
$("#one").fadeIn(6000,function() {
setTimeout(fadeTwo,6000);
})
.delay(3000)
.fadeOut(6000);
}
function fadeTwo() {
$("#two").fadeIn(6000,function() {
setTimeout(fadeThree,6000);
})
.delay(3000)
.fadeOut(6000);
}
function fadeThree() {
$("#three").fadeIn(6000,function() {
setTimeout(doFade,6000);
})
.delay(3000)
.fadeOut(6000);
}
doFade();
});
Edit:
You are currently setting a timeout to execute the next function, within the complete callback of fadeIn. This is a bit confusing to my mind, and I think it is simpler and clearer to do something like the following. In addition, there is no reason to define the three functions within the ready function - it is personal preference but I like to keep the amount of code within a callback to a minimum, such as...
$(document).ready(function() {
doFade();
});
function doFade() {
setTimeout(fadeTwo,12000);
$("#one").fadeIn(6000).delay(3000).fadeOut(6000);
}
function fadeTwo() {
setTimeout(fadeThree,12000);
$("#two").fadeIn(6000).delay(3000).fadeOut(6000);
}
function fadeThree() {
setTimeout(doFade,12000);
$("#three").fadeIn(6000).delay(3000).fadeOut(6000);
}
Edit 2:
In further effort to reduce the amount we repeat ourselves, we can extract the whole animation sequence into a function:
$(document).ready(function() {
doFade();
});
function fadeInThenOut(element) {
element.fadeIn(6000).delay(3000).fadeOut(6000);
}
function doFade() {
setTimeout(fadeTwo,12000);
fadeInThenOut($("#one"));
}
function fadeTwo() {
setTimeout(fadeThree,12000);
fadeInThenOut($("#two"));
}
function fadeThree() {
setTimeout(doFade,12000);
fadeInThenOut($("#three"));
}
Edit 3:
At this point we probably notice how similar our three functions are, and want some way to reduce that repetitiveness. So we could use recursion, and just change which element we pass in each time.
$(document).ready(function() {
doFade();
});
function doFade(elementNumber) {
const elementNumber = elementNumber < testimonialElements.length ? elementNumber : 0;
setTimeout(doFade(elementNumber + 1),12000);
$('#' + testimonialElements[elementNumber]).fadeIn(6000).delay(3000).fadeOut(6000);
}
var testimonialElements = ["one","two","three"];
While this solution may lose something in readability and simplicity, the great advantage is that when you add a fourth testimonial, you don't need to write a function to handle it. All you would do is change the testimonialElements array to include the new element id.
This is a followup to a question I asked yesterday. I'm having a different problem related to jquery promises.
function setOverrides2() {
var dfd = new $.Deferred();
// do something
return dfd.promise();
}
function overrideDialog1() {
var deferred = new $.Deferred();
ConfirmMessage.onConfirmYes = function() {
ConfirmMessage.hideAll();
// do stuff
deferred.resolve();
}
ConfirmMessage.onConfirmNo = function() {
ConfirmMessage.hideAll();
// do stuff
deferred.reject();
}
ConfirmMessage.showConfirmMessage("Do you wish to override primary eligibility?");
return deferred.promise();
}
function overrideDialog2() {
var deferred = new $.Deferred();
ConfirmMessage.onConfirmYes = function() {
ConfirmMessage.hideAll();
// do stuff
deferred.resolve();
}
ConfirmMessage.onConfirmNo = function() {
ConfirmMessage.hideAll();
// do stuff
deferred.reject();
}
ConfirmMessage.showConfirmMessage("Do you wish to override secondary eligibility?");
return deferred.promise();
}
setOverrides2().done(function(data) {
// shows both dialogs at once
overrideDialog().then(overrideDialog2()).then(function() {
alert("test");
});
// waits for one dialog to complete before showing the other
// overrideDialog1().done(function() {
// overrideDialog2().done(function() {
// alert("test two!");
// });
// });
});
As shown above, when I use done(), it works perfectly, but when I use then(), it shows both dialogs simultaneously. I want to be able to be able to use reject() to abort the chain the first time the user clicks the No button (defined by the onConfirmNo() callback).
The commented .done() section waits for one dialog to finish before triggering the next, but does not abort processing if the user clicks No on the first dialog.
I think I almost have this right, so if anyone can assist on this last piece of the puzzle, I'd greatly appreciate it.
Jason
overrideDialog().then(overrideDialog2())
Should be:
overrideDialog().then(overrideDialog2)
The reason done was working was because you wrapped it inside a function (which did not immediately execute)
I have been trying to scroll the page to a dynamic div that is created by the an ajax call.
When #divnotifications div clicked (below), I make the first ajax call that adds the Post details, then within this ajax call, another ajax call is made to add the related comments to the div.
The part explained so far works great. Then, I use $.when().then() to scroll to a div item created based on the ajax calls. However, the page does not scroll to the element that was created by LoadCommentsForPost ajax call.
Did I get the logic of $.when().then() wrong?
$(document).on('click', '#divnotifications div', function (event) {
event.preventDefault();
$.ajax({
//other details
success: function (postid) {
$.when(DisplayPostWithFullDetails(postid)).then(function () {
//scroll to the content created by
//LoadCommentsForPost function nested
//inside DisplayPostWithFullDetails
});
}
});
});
function DisplayPostWithFullDetails(postId) {
$.ajax({
//other details
success: function (post) {
//The code to build the div to display the post -- working fine
LoadCommentsForPost(post.PostId);
}
});
}
function LoadCommentsForPost(postid) {
$.ajax({
//other details
success: function (response) {
var comments = JSON.parse(response);
DisplayComments(comments);//builds the div to display the comments - working fine
}
});
}
UPDATED CODE
After receiving some feedback, I ended up with the following code. However, it is still not working. It works only if I add some delay to make sure the div is loaded:
$(document).on('click', '#divnotifications div', function (event) {
event.preventDefault();
$.ajax({
//other ajax stuff
success: function (postid) {
DisplayPostWithFullDetails(postid).done(function () {
setTimeout(function () {
var scrollto = $("div[data-" + type.toLowerCase() + "displayform='" + relateditem + "']").offset().top;
$("html, body").animate({ scrollTop: scrollto }, 600);
}, 500);
});
}
});
});
function DisplayPostWithFullDetails(postId) {
jQuery.support.cors = true;
return $.ajax({
//other ajax stuff
success: function (post) {
post = JSON.parse(post);
//display the post details
LoadCommentsForPost(post.PostId);
}
});
}
function LoadCommentsForPost(postid) {
var promise = new $.Deferred();
jQuery.support.cors = true;
$.ajax({
//other ajax stuff
success: function (response) {
var comments = JSON.parse(response);
DisplayComments(comments);//this is not ajax
promise.resolve('loadedcomments');
}
});
return promise;
}
Did I get the logic of $.when().then() wrong?
Yes, you need to return a promise from the functions if you want to use the function with $.when:
function DisplayPostWithFullDetails(postId) {
return $.ajax({...
// ^^^^^^
That said, wrapping a single promise in $.when is useless.
$.when(DisplayPostWithFullDetails(postid)).then(function () {
should just be:
DisplayPostWithFullDetail(postid).then(function () {
Did I get the logic of $.when().then() wrong?
No, but you are NOT returning the promise so you can't use the promise functions like .then().
UPDATE:
I use $.when().then() to scroll to a div item created based on the ajax calls. However, the page does not scroll to the element that was created by LoadCommentsForPost ajax call.
For me this means that you need to wait that both ajax calls are resolved.
This fiddle show how it should work emulating the ajax call using setTimeout Fiddle.
Your code may look similar to:
function DisplayPostWithFullDetails(postId) {
var promise = new $.Deferred();
$.ajax({
//other details
success: function (post) {
//The code to build the div to display the post -- working fine
LoadCommentsForPost(post.PostId).then(function() {
promise.resolve();
});
}
});
return promise;
}
function LoadCommentsForPost(postid) {
return $.ajax({
//other details
success: function (response) {
var comments = JSON.parse(response);
DisplayComments(comments);//builds the div to display the comments - working fine
}
});
}
Now when you execute the function DisplayPostWithFullDetails it return a promise.
So you can use .then() method;
DisplayPostWithFullDetails(postid)).then(function () {});
or...
var promise = DisplayPostWithFullDetails(postid);
promise.then(function(data){});
Also the major advantage of use $.when() is that you can execute the .then() method when all the promises that you pass to it are resolved.
There are not need to use it when you are waiting for a single promise.
I've got following JavaScript functions but want to refactor the $(document).ready() as I've got 2 instance of it. How can I achieve this?
FlashMessenger = {
init: function() {
setTimeout(function() {
$(".flash").fadeOut("slow", function () {
$(".flash").remove();
});
}, 5000);
}
}
SelectLanguage = {
init: function() {
$('#selectLanguageId').change(function() {
$('#frmSelectLanguage').submit();
});
}
}
$(document).ready(FlashMessenger.init);
$(document).ready(SelectLanguage.init);
It’s perfectly acceptable to set multiple handlers for $(document).ready, although you may have a good reason to do otherwise that I’m not aware of. You might be interested in knowing that $(handler) can be used as shorthand for $(document).ready(handler):
$(FlashMessenger.init);
$(SelectLanguage.init);
If you really want them in one call though, try this:
$(function() {
FlashMessenger.init();
SelectLanguage.init();
});
First off, there's no reason you have to combine them.
But if you want to:
$(document).ready(function(jq){
FlashMessenger.init(jq);
SelectLanguage.init(jq);
});
Breaking it down:
Create a function to do all your init (it can be named or anonymous; the one above is anonymous).
Have it call the other init functions, passing in the jQuery instance that jQuery passes you just in case they use it.
You might choose to wrap each init call in a try/catch block as well, so that errors in one init don't prevent the next init from occuring, but that depends on your needs.
Just combine them into one call with an anonymous function:
$(document).ready(function()
{
FlashMessenger.init();
SelectLanguage.init();
});
$(document).ready(function() {
FlashMessenger.init();
SelectLanguage.init();
});
Option 1
FlashMessenger = {
init: function() {
setTimeout(function() {
$(".flash").fadeOut("slow", function () {
$(".flash").remove();
});
}, 5000);
}
}
SelectLanguage = {
init: function() {
$('#selectLanguageId').change(function() {
$('#frmSelectLanguage').submit();
});
}
}
$(function(){
FlashMessenger.init();
SelectLanguage.init();
});
Option 2
FlashMessenger = {
init: function() {
setTimeout(function() {
$(".flash").fadeOut("slow", function () {
$(".flash").remove();
});
}, 5000);
}
}
SelectLanguage = {
init: function() {
$('#selectLanguageId').change(function() {
$('#frmSelectLanguage').submit();
});
}
}
$(document).ready(function(){
FlashMessenger.init();
SelectLanguage.init();
});
Option 3
You actually don't need those 2 objects since the only hold the init methods, so here's the ultimate solution, in my opinion, unless you use those objects elsewhere.
$(function(){
$('#selectLanguageId').change(function() {
$('#frmSelectLanguage').submit();
});
setTimeout(function() {
$(".flash").fadeOut("slow", function () {
$(".flash").remove();
});
}, 5000);
})
I prefer 2 and 3 for this reason.
I think what the op is saying is, "If in the future I have a third function to be invoked at document.ready, then how do I do it without touching that piece of code?"
If you do not want multiple $(document).ready() calls, you could just create an array called startupHooks and add each method to it:
startupHooks[ startupHooks.length ] = myNewStartupHook;
and your startup script could look like
$(document).ready(function() {
for( var i=0; i<startupHooks.length; i++ ) {
startupHooks[i]();
}
}
I know that is not mighty useful, but if that appeals to you, you can do it this way.
Personally, I'd go with multiple $(document).ready() calls.
Personally I'd go for not using document.ready at all.
If you place the scripts at the end of your html-page(just before the tag) you can just write in any way you like.
Maybe this doesn't work for 0.01% of the scripts but it never failed to work for me.
Positive effect of this is that the initial HTML+CSS rendering goes faster.
You can also read about it on yahoo. http://developer.yahoo.com/performance/rules.html#js_bottom
I have a big problem writing a small piece of code using JS/jQuery (don't know which of these is causing the problem). Anyhow, here we go:
$('#themePicker').unbind().click(function() {
var t = $(this);
modalwindow2(t, function() {
console.log(1);
}, function(w) {
console.log(w);
});
return false;
});
and the function itself:
function modalwindow2(w, callbackOnSHow, callbackOnHide) {
if (typeof(callbackOnSHow) == 'function') {
callbackOnSHow.call();
}
// do some stuff //
$('form').submit(function() {
ajaxSubmit(function(data) {
if (typeof(callbackOnHide) == 'function') {
console.log('---------------');
console.log(data);
console.log('---------------');
callbackOnHide.call(data);
}
});
return false
});
}
The function is called modalwindow2 and I want to call a function when the modal is shown and another function when the modal will be hidden.
The first is not a problem.
The second… Well… Let's just say it's a problem. Why?
I want a parameter sent to the second function. The paramenter is an ajax response, similar to other jQuery stuff (ajax action, sortable, etc).
I hope I made myself clear enough.
Thanks!
Edit:
I'm using jQuery 1.1.2 (or 1.1.3) and upgrading or using jQuery UI is NOT a solution. I have some dependencies (interface is one of them) and i don't have enough time (nor motivation) to upgrade to 1.3 & UI 1.7.
I noticed that you have a typo on .submit:
$('form').submti(function(){
Was that just an entry error to SO?
EDIT:
Ok, so after looking at your code and doing a short test, I've come up with this (pardon the pun):
function modalwindow2(w, callbackOnShow, callbackOnHide) {
if(typeof callbackOnShow == 'function') {
callbackOnShow.call();
}
$('form').submit(function() {
if(typeof callbackOnHide == 'function') {
callbackOnHide.call(this, "second");
}
});
}
$(document).ready(function (){
$('#themePicker').click(function(){
var t=$(this);
modalwindow2(t, function() { alert("first"); }, function(x) { alert(x); });
return false;
});
});
It looks like you may have just been missing the "this" in your call() statement. Try using callbackOnHide.call(this, data);
Let me know if that works any better!
I understand what you are trying to do, but you will need to store the newly created window so that you can access it on the close callback function.
You might want to look at jQuery UI Dialog. It provides some really basic functionality for dialog windows (modal and otherwise) and handles some of the callback implementation.