transition effects in html with handlebars - javascript

I've built an app where I browse instagram API and fetch photos. After that is done I use Handlebars to make a template with undordered list and images inside. I'm trying to get images to slowly fade in as soon as the template is loaded, but to no avail. So far it looks like this
In my template I add class hidden that sets the opacity to 0, so then I can just remove the class to show the image.
<template id="image-template" type="text/x-handlebars-template">
<ul>
{{#each this}}
<li>
<img class="hidden" src="{{url}}">
</li>
{{/each}}
</ul>
</template>
After setting everything in JS
var template = Handlebars.compile( source.html() )
var html = template( images )
$('#container').html( html )
At this point I should have the images in the container, so I should be able to use
$('img').removeClass('hidden')
and have images slowly fade in, however thats not happening.
After a bit of investigating I realised that those images aren't quite available for me, so I set up a pub/sub after adding template to html
$('#container').html(html)
$.publish('insta/photoTransition')
I was sure that calling another function after this would work, but still no result. After that just out of ideas I setTimeout before publishing, and what do you know, my assumptions were true and with a delay it finally worked. However I don't want to wait a set amount of time to show the photos, I would like to show them as soon as possible. Before I try to figure out how deferreds work to try my last idea, are there any better ways to solve my problem?

Just use css transitions.
#image-template img{
opacity: 1;
transition: opacity 0.4s ease-in;
-moz-transition: opacity 0.4s ease-in;
-webkit-transition: opacity 0.4s ease-in;
}
#image-template img.hidden{
opacity: 0;
}

Related

bootstrap/jQuery fade opacity transition not working

I am hoping someone can help!
I am trying to add bootstrap support to an existing jQuery/CSS site. Aside from realizing bootstrap changes a bunch of formatting that I have to fix - it seems to be affecting a popup transition I have, and can't seem to figure out. I hope you can help, thanks!
With regular jQuery/CSS (not UI), I am creating a modal dialog box that I popup.
BEFORE bootstrap - it would "fade" in the popup box (i.e., the opacity/alpha). However, AFTER adding the bootstrap .css/.js - now it just
makes the background grey and totally opaque.
How do I fix it?
This is the code that works with just css/jQuery
<div class=sample-dialog>
<div class=modal-overlay>
<div class=modal-content>
<div class=modal-body>
random content
</div>
</div>
</div>
</div>
then the jQuery popup code that I call
function showModal() {
var m = $('.sample-dialog');
var o = m.find('.modal-overlay');
var c = m.find('.modal-content');
var b = c.find('.modal-body');
m.css('display','block');
o.animate({'opacity':.8},350);
b.animate({'opacity':1,'margin-top':0},350,function() {
c.css('overflow-y','auto');
});
}
This "works" with just the jQuery/css.
HOWEVER, as soon as I add the bootstrap .js/.css file in my header, the exact same transition now shows no opacity (just a grayed out background).
Any idea on how to fix?
As a second thing - I also notice with the bootstrap files added, the transition seems to be 'choppy' as opposed to the nice 'smooth' one I had. If you have insight for that too, that would be great!
Thanks very much!
It may be that the rules of bootstrap transitions are creating conflict, I remember working with version 4.0.0-alpha.6 it was impossible to modify the transition of the height in a model.
These would be the default values ​​of the modal transition (
with the .fade class)
_transitions.scss
.fade.show {
opacity: 1;
}
.fade {
opacity: 0;
-webkit-transition: opacity 0.15s linear;
-o-transition: opacity 0.15s linear;
transition: opacity 0.15s linear;
transition-property: opacity;
transition-duration: 0.15s;
transition-timing-function: linear;
transition-delay: initial;
}
This I think could help you;
Enables predefined transitions on various components
$enable-transitions: true (default) or false
Documentation bootstrap#4.0.0-alpha.6 /Customizing variables
Sorry if the bootstrap version does not help, but it's the only version I've worked with.

Angular ngAnimate list items automatically fade out

I have a weird issue with ngAnimate in a simple application I'm doing with the MEAN Stack.
Both angular.js and angular-animate.js are 1.4.7 version.
I have an ul that looks something like this:
<ul>
<li ng-repeat="item in items" class="fade">
{{item.name}}
</li>
</ul>
In the controller I'm getting the items array with an $http.get() call to the MongoDB.
This is the CSS code for the simple animation:
.fade {
transition: 1s linear all;
-webkit-transition: 1s linear all;
}
.fade.ng-enter {
opacity: 0;
}
.fade.ng-enter.ng-enter-active {
opacity: 1;
}
If for example I refresh the page,the controller gets the items array from the Database, and the list items fade in, but they fade out right after the fade in effect.
What is causing this undesired fade effect back to opacity:0 ? Could it be the way the functions I'm using the get the data interact with the view?
It turns out it was a default Bootstrap.css class called '.fade', which has opacity:0 rule;
Overriding that class in my style.css solved the undesired fade out. I hope it helps.

hide/unhide HTML portions by hovering?

more precisely, I've seen websites where there's a kind of header image, which loops through 3-4 different images, and each image is referenced by a dot, and you can pick the image you want by clicking the dot as well. I'm sure everyone has seen this somewhere.
as an example, go to http://www.tsunamitsolutions.com/
my question is, how do I make these dots appear/disappear when I hover on the image (like on the site I shared above) is it javascript or can this be accomplished just in the CSS with the "hover" style.
In other words, can hovering over one html portion/div/section make another div/section appear/disappear just by using CSS?
It can be done in the CSS.
Assuming the dots/arrows are child elements of banner container, you can do something like:
.bannerContainerClass .dotClass {
display: none;
}
.bannerContainerClass:hover .dotClass {
display: block;
}
You can also do it in jQuery if you need effects like fade:
$(".bannerContainerClass").hover(function() {
$(this).children(".dotClass").fadeIn(500);
}, function() {
$(this).children(".dotClass").fadeOut(500);
});
The jQuery method can be modified to work even if the dots aren't children of banner container.
You can accomplish it using Jquery and javascript. As in any website header images there is a tag for image one tag for collection of those points.
Suppose.
<div id="header_image">
..code for header image..
</div>
which is header tag. and there is a tag which cointains the points.
<div id="points_container">
..code for points...
</div>
Now in its javascript code if you want to disappear "points_container" tag when mouse is hovered over "header_image".and appears again when mouse is hovered out, you can write in its Javascript code.
$(document).ready(function(){
$("#header_image").hover(function(){
$("#points_container").hide();
},function(){
$("points_container").show();
});
});
You can use css on hover with either the visibility attribute or opacity attribute to hide an object, the full implementation of a gallery widget like this is somewhat more complicated though. CSS solution:
.dots:hover
{
opacity:0;
}
Makes anything with the dots class invisible on mouse over.
Or if you don't want it to take up any space when invisible:
.dots:hover
{
display:none;
}
Try this with simple CSS transitions, like this
HTML
<div id="parent"><br/><span class="bullets">* * * *</span></div>
CSS
.bullets{
opacity:1;
}
#parent:hover > .bullets{
opacity:0;
transition: opacity .2s ease-out;
-moz-transition: opacity .2s ease-out;
-webkit-transition: opacity .2s ease-out;
-o-transition: opacity .2s ease-out;
}
FIDDLE HERE>>

Restart CSS animation on the same element

I'm just getting started with CSS animations controlled via Javascript, and I'm stuck with a problem that I'm sure it's quite simple...
What am I trying to achieve?
I want to have a kind of image zone where some images are displayed with an increasing opacity effect: I want each new image to appear upon the other when the user clicks on the image.
How am I trying to achieve it?
I have a "div" which contains two "img" tags, and I'm simply trying to just animate the upper "img" and then swap the image "src" when the new image has to be shown. Let me explain it:
"img1" is the image at the bottom, which is showing "My first photo".
"img2" is the image at the top, which starts with an opacity of 0.
When the user clicks the image, "My second photo" is associated with the "img2", and "img2" starts and animation to fade in.
When the user touches again, "img1" changes its "src" to show "My second photo", "img2" changes its alpha to 0, changes its source to "My third photo" and starts the fade in animation again.
And so on, making the effect that the new image is always appearing upon the current one.
The bizarre part: the code
As I'm still quite green on CSS animations and Javascript, I'm trying to do it as follows:
index.html:
<div style="position:absolute; top:50%; left:50%; margin-left:-114px; margin-top:-203px;" onClick="canviaImatge();">
<img id="img_1" class="pantalla" src="" style="position:absolute;" />
<img id="img_2" class="pantalla" src="" style="position:relative; left:50px" />
</div>
<script>
document.getElementById("img_1").src = arrImatges[0];
document.getElementById("img_2").src = arrImatges[1];
document.getElementById("img_2").style.opacity = 0;
</script>
index.html (Javascript)
function canviaImatge()
{
document.getElementById("img_2").style.opacity = 0;
document.getElementById("img_2").classList.remove('horizTranslateApareix');
if(currentPantalla == 1)
{
document.getElementById("img_1").src = arrImatges[0];
document.getElementById("img_2").src = arrImatges[1];
}else{
document.getElementById("img_1").src = arrImatges[1];
document.getElementById("img_2").src = arrImatges[0];
}
document.getElementById("img_2").classList.add('horizTranslateApareix');
}
style.css
.pantalla.horizTranslateApareix {
-webkit-transition: 1s;
-moz-transition: 1s;
-ms-transition: 1s;
-o-transition: 1s;
transition: 1s;
opacity: 1 !important;
}
I know I'm doing it the dirty way, but it's like I'm just there and it seems that I'm just missing a line, a tag or something... Any clue about it?
Thanks in advance for your time and effort! :)
When you bind event handler on div as well as on images inside the div, it will be called twice as there is no e.preventBubble() in event handler. You can avoid this by using it only on the div.
Second issue is that after first click inside the div, the transition is in final state and you don't move it to initial state. I would achieve required behavior by using 2 classes. One for transition and one for initial state, final state is implicit here, opacity:1 is default value.
.pantalla.invisible {
opacity: 0;
}
.pantalla.horizTranslateApareix {
-webkit-transition: 1s;
-moz-transition: 1s;
-ms-transition: 1s;
-o-transition: 1s;
transition: 1s;
}
Main part is in JS. We start by removing the transition, otherwise it would took 1s to hide the image as well. Then we hide the image and return the transition, do image swapping and finally show the image again, starting the transition.
function canviaImatge()
{
img2.classList.remove('horizTranslateApareix');
img2.classList.add('invisible');
img2.offsetHeight; // <-- force repaint, otherwise browser optimize and nothing changes
img2.classList.add('horizTranslateApareix');
// image swapping
img2.classList.remove('invisible');
}
This would be the ideal case, but browsers optimize, so we can't use it as simply as that. Browsers do as much as possible without repainting the page, so they merge several opearions to one and we loose our functionality. That's where magic comes in place. We enforce repaint asking for img2.offsetHeight, which has to recalculate positions and repaint the relevant part of page (possibly whole page). Other ways to achieve it, is to move code to setTimeout function, which can't be optimized either.
setTimeout(function() {
img2.classList.add('horizTranslateApareix');
img2.classList.remove('invisible');
}, 1)
Demo at http://jsfiddle.net/Gobie/e4m3R/2/

Animate opacity on image load

I have tried a bunch of different solutions to similar problems on here but none of them seem to be doing anything for me. See my jsFiddle to see an example of what I would like to happen: http://jsfiddle.net/Amp3rsand/HSNY5/6/
It animates how I would like but it relies on .delay when I would prefer it to fire as soon as the image is finished loading. The commented out sections in the js are the things that I have tried.
Could the problem be that the image is actually the background of a div rather than its own element? I tested making it its own <img> tag as well but it didn't seem to make a difference. I have the image as the background so that when I use media queries it is easy to swap in a different, smaller image for mobile users or small screens.
HTML:
<header></header>
<div id="image">
<div id="blah"></div>
</div>
The image I would like to fire after it finishes loading is the background of '#image'. Then I would like for it to animate to 'opacity:1;' while '#blah' and 'header' are animated into place.
Here is the jQuery I'm using right now but it is not correct:
$('#image').hide().delay(800).fadeTo(600, 1);
$('#blah').css("left", "-650px").delay(1400).animate({left:'30px'},400);
$('header').css("top", "-150px").delay(2000).animate({top:'-5px'},400);
On my website it is quite a large image so it takes about half a second to load but this code doesn't take into account caching or different network speeds.
What am I doing wrong or what should I do differently?
Thanks everyone
EDIT:
I gave the imagesLoaded plugin a go earlier and it seems to work on my website but I can't tell if it is actually doing what I want or just emulating my code from above.
$(document).ready(function() {
$('body').hide().fadeTo(500, 1)
});
imagesLoaded( document.querySelector('#homeimg'), function( instance ) {
$('article').hide().fadeTo(600, 1);
$('#caption').css("left", "-650px").delay(800).animate({left:'30px'},400);
$('header').css("top", "-150px").delay(1400).animate({top:'-5px'},400);
});
'#homeimg' being the div with the image as the background and 'article' being the container for '#homeimg' and '#caption'
I can only test with the website loaded locally at the moment so I can't simulate a slow connection. Does the code above do what I am looking for? Sorry if it should be obvious
Your image is loaded via a CSS background property, you will not be able to detect the loading of that. Why not use <img> tag for images?
If you use <img> you can read this question: Browser-independent way to detect when image has been loaded for a bullet-proof solution.
If you insist on using a background CSS property you will need to implement a way of sending your image as a data url encoded as base64 as described in this answer: https://stackoverflow.com/a/13989806/2788
Try animate
$('#image').animate({ opacity: '1'}, 600);
You can set the initial opacity to 0, and when the image onloaded, set the opacity to 1. With CSS you can make a transition between the two states:
<style>
.easeload{
opacity: 0;
-webkit-transition: all 2s ease;
-moz-transition: all 2s ease;
-ms-transition: all 2s ease;
-o-transition: all 2s ease;
}
</style>
<img class="easeload" onload="this.style.opacity=1" src="https://dummyimage.com/320x240">

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