I've used react for quite some time and wanted to try out Mithril.js.
Went through the documentation and the examples and liked what I saw, so I said I should get my hands dirty and start coding!
I have a smiple API call that receives a JSON data and then outputs ul list with all the items. I've integrated GSAP TweenMax for animations and what I'm trying to achieve is very simple - I fade everything in, on onload and then onclick I want to fade to fade an element out and remove it from DOM / data.
What seems to be happening is that the element is fading out, the whole ul list is being re-rendered and that element remains in the DOM with 0 opacity:
var Item = {
list: function() {
return m.request({method: 'GET', url: '/api/items'});
}
}
var dm = {
controller: function(data) {
var items = Item.list();
return {
items: items,
remove: function(item) {
items().data.splice(items().data.indexOf(item), 1);
}
}
},
view: function(ctrl) {
return m('ul', [
ctrl.items().data.map(function(item, id){
return m('li',{
key: id,
config: fadesIn,
onclick: fadeOut(ctrl.remove.bind(this, item))
}, item.title);
})
]);
}
}
var fadesIn = function(element){
var tl = new TimelineMax();
tl.from(element, .5, {opacity: 0});
}
var fadeOut = function(callback) {
return function(e) {
m.redraw.strategy('none');
TweenMax.to(e.target, .5, {opacity: 0, onComplete: function() {
m.startComputation();
callback();
m.endComputation();
}});
}
}
m.mount(document.getElementById('test'), dm);
I'm very new.. started reading up just yesterday.
Getting animation libraries to work with Mithril can be tricky. When libraries manipulate DOM state the synchronization with Mithril state can be broken.
Fortunately that wasn't the case: What you're missing is the isInitialized parameter for the config function, which is false only on the first call. Testing for that makes the fade-in only happen once:
var fadesIn = function(element, isInit){
if(isInit) return;
var tl = new TimelineMax();
tl.from(element, .5, {opacity: 0});
}
In this simple example the redrawing can also be simplified, I've made a fiddle with a working example:
http://jsfiddle.net/ciscoheat/dkyc0ryc/
Since there are no DOM manipulations a call to m.redraw is enough to remove the div from DOM, but you're probably right in using start/endComputation when things get more complex. I would even move m.startComputation above the TweenMax.to call to make it extra safe, but if many other things are happening at the same time, that may block other redraws. You have to find a balance. :)
The call to m.redraw.strategy isn't needed in any case, I think. It's mostly used when you want nothing at all to happen (synchronously as well), but an async animation is starting so it won't have any effect.
Edit: Found another problem, the key cannot be set to the index of the map function, then it will change when an item is removed, messing up the redraw. I've updated the fiddle to use item.title as key instead.
Related
Im a really huge noob on jquery, I need to figure out how to change this code:
$('.social li').appear();
$(document.body).on('appear', '.social li', function(e, $affected) {
var fadeDelayAttr;
var fadeDelay;
$(this).each(function(){
if ($(this).data("delay")) {
fadeDelayAttr = $(this).data("delay")
fadeDelay = fadeDelayAttr;
} else {
fadeDelay = 0;
}
$(this).delay(fadeDelay).queue(function(){
$(this).addClass('animated').clearQueue();
});
})
});
to work in the way that it would start animation as soon as someone enters the landing page, right now it works good on everything besides IE10 and IE11, was told to change it to load by default not on "appear" but I tried document ready/load and I can't get it to work...
You could try fading all list items into view, each with a progessing 250ms delay:
$(window).load(function() {
$('.social li').hide().each(function(i) {
$(this).delay((i + 1) * 250).fadeIn(2000);
});
});
EDIT:
Using the same logic as your previous code to refactor, use the window.load method since the load event fires at the end of the document loading process. At this point, all of the objects in the document are in the DOM, and all the images and sub-frames etc have finished loading. So use this event to do the fading in animation of the list items into view, where their initial state will be hidden.
You have two variables declared fadeDelayAttr and fadeDelay but I noticed that only fadeDelay is being used, so fadeDelayAttr can be discarded. Also, this part of the code:
if ($(this).data("delay")) {
fadeDelayAttr = $(this).data("delay")
fadeDelay = fadeDelayAttr;
} else {
fadeDelay = 0;
}
can be simplified as the null-coalescing operator using a logical OR (||):
var fadeDelay = $(this).data("delay") || 0;
Since the fadeDelay variable gets its value from the data-delay attribute, this can then be passed in as an argument for the delay method and finally the refactored code will look like this:
$(window).load(function() {
$('.social li').hide().each(function() {
var fadeDelay = $(this).data("delay") || 0;
$(this).delay(fadeDelay).fadeIn(2000);
});
});
Working Demo
Well I hope the question is self-explanatory. I have the following code:
$(window).scroll(function () {
var scrollTop = $(window).scrollTop();
if (scrollTop > sliderTop) {
$('#slider').slideDown(1000);
} else {
$('#slider').slideUp(1000);
}
});
If I scroll down after a certain point the slideDown function will be called continuously. does JQuery animates it over and over again or is it smart enough to know that the element is already slide down? (currently I'm using a flag to check whether its already slide down).
The animation won't run again. See lines 459-468 in effect.js in the jquery src
doAnimation = function() {
// Operate on a copy of prop so per-property easing won't be lost
var anim = Animation( this, jQuery.extend( {}, prop ), optall );
// Empty animations, or finishing resolves immediately
if ( empty || data_priv.get( this, "finish" ) ) {
anim.stop( true ); // ** here - stopping right after started.
}
};
doAnimation.finish = doAnimation;
But I would still recommend against it to improve code readability. just use a boolean, it doesn't hurt...
So I've created the following function to fade elements in and passed in a div that I want to fade in which in this case is an image gallery popup that I want to show when a user clicks an image thumbnail on my site. I'm also passing in a speed value (iSpeed) which the timeout uses for it's time value. In this case I'm using 25 (25ms).
I've stepped through this function whilst doing so it appears to be functioning as expected. If the current opacity is less than 1, then it is incremented and it will recall itself after the timeout until the opacity reaches 1. When it reaches one it stops fading and returns.
So after stepping through it, I take off my breakpoints and try to see it in action but for some reason my gallery instantly appears without any sense of fading.
var Effects = new function () {
this.Fading = false;
this.FadeIn = function (oElement, iSpeed) {
//set opacity to zero if we haven't started fading yet.
if (this.Fading == false) {
oElement.style.opacity = 0;
}
//if we've reached or passed max opacity, stop fading
if (oElement.style.opacity >= 1) {
oElement.style.opacity = 1;
this.Fading = false;
return;
}
//otherwise, fade
else {
this.Fading = true;
var iCurrentOpacity = parseFloat(oElement.style.opacity);
oElement.style.opacity = iCurrentOpacity + 0.1;
setTimeout(Effects.FadeIn(oElement, iSpeed), iSpeed);
}
}
}
Here's where I'm setting up the gallery.
this.Show = function (sPage, iImagesToDisplay, oSelectedImage) {
//create and show overlay
var oOverlay = document.createElement('div');
oOverlay.id = 'divOverlay';
document.body.appendChild(oOverlay);
//create and show gallery box
var oGallery = document.createElement('div');
oGallery.id = 'divGallery';
oGallery.style.opacity = 0;
document.body.appendChild(oGallery);
//set position of gallery box
oGallery.style.top = (window.innerHeight / 2) - (oGallery.clientHeight / 2) + 'px';
oGallery.style.left = (window.innerWidth / 2) - (oGallery.clientWidth / 2) + 'px';
//call content function
ImageGallery.CreateContent(oGallery, sPage, iImagesToDisplay, oSelectedImage);
//fade in gallery
Effects.FadeIn(oGallery, 25);
}
Could anyone help me out?
Also, I'm using IE10 and I've also tried Chrome, same result.
Thanks,
Andy
This line:
setTimeout(Effects.FadeIn(oElement, iSpeed), iSpeed);
calls Effects.FadeIn with the given arguments, and feeds its return value into setTimeout. This is exactly like foo(bar()), which calls bar immediately, and then feeds its return value into foo.
Since your FadeIn function doesn't return a function, that would be the problem.
Perhaps you meant:
setTimeout(function() {
Effects.FadeIn(oElement, iSpeed);
}, iSpeed);
...although you'd be better off creating that function once and reusing it.
For instance, I think this does what you're looking for, but without recreating functions on each loop:
var Effects = new function () {
this.FadeIn = function (oElement, iSpeed) {
var fading = false;
var timer = setInterval(function() {
//set opacity to zero if we haven't started fading yet.
if (fading == false) { // Consider `if (!this.Fading)`
oElement.style.opacity = 0;
}
//if we've reached or passed max opacity, stop fading
if (oElement.style.opacity >= 1) {
oElement.style.opacity = 1;
clearInterval(timer);
}
//otherwise, fade
else {
fading = true;
var iCurrentOpacity = parseFloat(oElement.style.opacity);
oElement.style.opacity = iCurrentOpacity + 0.1;
}
}, iSpeed);
};
};
Your code has a lot of problems. The one culpable for the element appearing immediately is that you call setTimeout not with a function but with the result of a function, because Effects.FadeIn will be executed immediately.
setTimeout(function(){Effects.FadeIn(oElement, iSpeed)}, iSpeed);
will probably act as you intend.
But seriously, you probably should not re-invent this wheel. jQuery will allow you to fade elements in and out easily and CSS transitions allow you to achieve element fading with as much as adding or removing a CSS class.
T.J. and MoMolog are both right about the bug: you're invoking the Effects.FadeIn function immediately before passing the result to setTimeout—which means that Effects.FadeIn calls itself synchronously again and again until the condition oElement.style.opacity >= 1 is reached.
As you may or may not know, many UI updates that all take place within one turn of the event loop will be batched together on the next repaint (or something like that) so you won't see any sort of transition.
This jsFiddle includes the suggested JS solution, as well as an alternate approach that I think you may find to be better: simply adding a CSS class with the transition property. This will result in a smoother animation. Note that if you go this route, though, you may need to also include some vendor prefixes.
I am trying to create an effect where on button click, the div would shake left and right and tilt about 10deg each way so it looks like a natural motion when shaking an object with two hands. I am able to create the left and right shaking effect but can't seem to tie it in with rotation. I also need this to work in IE8, so css3 is not an option. I am using JQuery UI and .rotate() but if there is a better way please let me know. I need this to shake about 3-4 times on button click.
<div class="container">
<div class="globe-main" id="globe">
<div class="content"></div><!-- end .content -->
</div><!-- end .globe-main -->
</div><!-- end .container -->
<script>
var times = 4;
var loop = setInterval(rota, 300);
function rota() {
times--;
if(times === 0){clearInterval(loop);}
$(".globe-main").rotate({animateTo:10, duration: 500, });
//$(".globe-main").effect("shake", { times:3, distance:30 }, 800);
}
rota();
</script>
Here is what I have so far FIDDLE
Thank you
UPDATE
Here is the updated FIDDLE
jQuery has no method called rotate. This is probably where the problem lies.
Edit
Based on your comments, you could create your own queue I guess...
rotationAnimationQueue = {
queue: [],
addAnimation: function( $jQueryObject, params ) {
// add animation to the queue
this.queue.push( {
$jQueryObject: $jQueryObject,
params: params
} );
// if only animation in queue, begin processing
if ( this.queue.length === 1 ) this.processQueue();
},
processQueue: function() {
var self = this;
var animation = this.queue[ 0 ];
animation.params.callback = function() {
self.queue.shift();
if ( self.queue.length > 0 ) self.processQueue();
};
animation.$jQueryObject.rotate( animation.params );
}
};
See it in action here: http://jsfiddle.net/UnyYh/1/
You may want to modify the queue code so that it keeps track of one queue per jQuery object. This way if needed you could have shake animations happening on multiple objects at the same time instead of always doing the animations in sequence.
I have an event listener that calls two animation actions. Unfortunately their starts are staggered by a small amount (e.g. the first in the function starts first).
Does anyone know a way to properly sync them up?
Here's my code:
$("#nav ul li a").hover(
function(){
$(lastBlock).children("div").animate({width: "0px"}, { queue:false, duration:400, easing:"swing" });
$(this).children("div").animate({width: maxWidth+"px"}, { queue:false, duration:400, easing:"swing"});
lastBlock = this;
}
);
Because the first animation runs slightly before the second, it causes the overall width to become momentarily unequal, which looks a bit funky.
There was a recent disussion about this exact topic on the jQuery dev list. They created a few test cases you might wanna look at. Specially the Johns test.
Here's the discussion topic btw.
The trick is to have a single interval/callback in which all elements are updated.
You can find an example in my post here:
Can I implement a callback with each animation step in jQuery?
What you end up is basically:
var el1 = $("#element1");
var el2 = $("#element2");
var animation = new AnimationTimeline( {
easing: "swing"
, onstep: function( stepValue, animprops )
{
// This is called for every animation frame. Set the elements:
el1.css( { left: ..., top: ... } );
el2.css( { left: ..., top: ... } );
}
});
// And start it.
animation.start();