Develop Reference

when loading swiper slide, height changes

I'm initializing swiper with below code:
var mySwiper = new Swiper('.swiper-container', {
speed: 400,
slidesPerView: 3,
autoplay: {
delay: 3000,
},
});
But when the page loads it shows big blue space followed by slides which adds to Layout shift in Google Pagespeed score. Can anybody point out whats wrong?

E D I T:
Just select the swiper default wrapper and set it's height & width properties to whatever size you wish like this:
.swiper-wrapper {
max-height: 100vh;
height: 100vw;
}
By default this should do it, you might also want check if you didn't set specific dimensions on single slides in your css!

How to avoid transparent background using cropping plugin

I'm using this cropping tool https://github.com/fengyuanchen/cropper/. I have this issue, that if I add an image dynamically there is some transparent background around the image. So the image does not fit the container and it also makes it possible to crop around the image. I followed the examples on the docs to try to get rid of the transparent background, but with no success.
here is my code:
<div id="imgWrap" style="max-height:400px;min-height:400px">
<img id="img" src="" /> // Image gets added dynamically
</div>
the javascript
var reader = new FileReader();
reader.onloadend = function () {
var img = $('#imgWrap img');
img.attr('src', reader.result);
img.cropper({
aspectRatio: 1 / 1,
autoCropArea: 0.65,
guides: false,
strict: true,
highlight: false,
responsive:true,
dragCrop: false,
movable: true,
resizable: true,
zoomable: true,
touchDragZoom:true,
rotatable: false,
minCropBoxWidth:105,
minCropBoxHeight:105,
built: function () {
// cropper-container is the element where the image is placed
$('.cropper-container').cropper('setCanvasData', {
left: 0,
top: 0,
width: 700,
height: 700
}
);
},
})
I tried to this: https://github.com/fengyuanchen/cropper#setcanvasdatadata but nothing happens
You can see an example here:
The natural size of the image is 1920x1200
This is what is generated after the image is added:
So, does anyone have a suggestion how to get rid of the transparent background and make the image fit the container?

I had the exact same issue. In the Cropper doc it says to set the img max-width = 100%. I did this and it fixed the issue
https://github.com/fengyuanchen/cropper
/* Limit image width to avoid overflow the container */
img {
max-width: 100%; /* This rule is very important, please do not ignore this! */
}

Setting background property of cropper object to false fixes this problem.

You can set option:
aspectRatio: 1 / 1, // select area ratio 16:9, 4:3, 1:1, 2:3, free
viewMode: 3, // sketch image to fit the container

In case someone else gets a similar problem, I fixed mine by encasing the <img> its in own div. Cropper (at least in 2.0.1) defines the container with
$cropper.css((this.container = {
width: max($container.width(), num(options.minContainerWidth) || 200),
height: max($container.height(), num(options.minContainerHeight) || 100)
}));
and $container is created with this.$container = $this.parent(); so if you have padding, some other lines of code, etc it calculates its size along with those lines. Given the age of this though, I doubt OP can validate if that was his problem or not.

I had a same problem and solution was easy.
Everything what you need is setup your css height, width to your cropper selector instead of cropper but after init cropper. This is normal jQuery object and you call cropper init on him later. As latest thing you'll setup new visual variables.
var $area = $('div.crop-area-image'); // jquery object
$area.cropper(options); // init cropper
$area.css({height: '300px'}); // setup css
voala .. thats all!

Unfortunatelly
/* Limit image width to avoid overflow the container */
img {
max-width: 100%; /* This rule is very important, please do not ignore this! */
}
is not enough. This only fixes top and bottom empty space issue.
I had to add display: inline-block; to my container to clamp canvas and image boxes: https://jsfiddle.net/h9ktgxak/

Use fillColor option in the getCroppedCanvas method
Also, make sure to use full color name ('#ffffff') not ('#fff')
getCroppedCanvas({fillColor:'#ffffff'}).toBlob((blob) => {});

You call setCanvasData method on wrong element.
You should call it on the image:
...
img.cropper({
...
built: function () {
img.cropper('setCanvasData', {
left: 0,
top: 0,
width: 700,
height: 700
});
}
});
...

How to change div img when scrolling down a page

Pretty simple javascript issue that I am not sure how to do:
When scrolling down on the website:
http://cerebral-supplements.myshopify.com/ (use password "aiglog")
the header shifts up into a minimalistic design. As the logo is too big it sticks out.
What javascript code would be needed to change the logo's div properties to resize the image?
Thanks

If you can add custom CSS, add the following:
/* scale logo down to ~75% size when scrolled sidebar is activated (fadeInDown class) */
.fadeInDown .template-logo img {
width: 225px;
height: 61px;
}

modify the functions values to your needs.
function onScrollChange()
{
if ( document.body.scrollTop > 500 ) {
var divElement = document.getElementById('divID');
// either change style properties directly
divElement.style.width = '100px';
divElement.style.height = '100px';
// or change the div's css class
divElement.classname = 'smallLogoClass';
}
}
than register it, so it executes on each scroll.
document.addEventListener('scroll', onScrollChange);

set dynamic content on slider div

I am trying to use one of these two jquery plugins (awkward/Coda Slider 3) for sliding DIV content.
Everything works fine until I am try to set dynamic content (with js) after the plugin object has been created.
The DIVs show only content that loaded before the plugin created.
Any ideas or other DIV slider plug-in's for this goal.
Thanks.
the ajax working perfect I have checked it.
this is the load function for coda slider $('#slider-id').codaSlider();
and for "awkward" :
$(window).ready(function () {
$("#showcase").awShowcase(
{
content_width: 700,
fit_to_parent: false,
auto: false,
interval: 3000,
continuous: false,
loading: true,
tooltip_width: 200,
tooltip_icon_width: 32,
tooltip_icon_height: 32,
tooltip_offsetx: 18,
tooltip_offsety: 0,
arrows: true,
buttons: true,
btn_numbers: false,
keybord_keys: true,
mousetrace: false, /* Trace x and y coordinates for the mouse */
pauseonover: true,
stoponclick: true,
transition: 'fade', /* hslide/vslide/fade */
transition_speed: 500,
transition_delay: 300,
show_caption: 'onhover', /* onload/onhover/show */
thumbnails: true,
thumbnails_position: 'outside-last', /* outside-last/outside-first/inside-last/inside-first */
thumbnails_direction: 'horizontal', /* vertical/horizontal */
thumbnails_slidex: 0, /* 0 = auto / 1 = slide one thumbnail / 2 = slide two thumbnails / etc. */
dynamic_height: true, /* For dynamic height to work in webkit you need to set the width and height of images in the source. Usually works to only set the dimension of the first slide in the showcase. */
speed_change: false, /* Set to true to prevent users from swithing more then one slide at once. */
viewline: false /* If set to true content_width, thumbnails, transition and dynamic_height will be disabled. As for dynamic height you need to set the width and height of images in the source. */
});
});

Kevin Batdorf has improved on the Coda Slider with something called Liquid Slider which supports ajax and callbacks.
Read a tutorial on it here
And it is available on github.

Background fade in on click

I am trying get this background to fade in on click. I found one tutorial that was helpful, and I ended up created the code so it has two images, and they fade in and out on click to bring up the picture.
Here's the work: http://www.mccraymusic.com/bgchangetest.html
Only a couple of issues though:
How do I make this work without the images getting selected at random? I'd like it to just switch from the plain black image to the image with the drum set. (And cross-fade to if possible, but not necessary)
How do I center the image on the page, so the image of the drums are centered?

I'm guessing this is what you're after:
$(function() {
var images = ["black.jpg","bg.jpg"];
$('<img>').attr({'src':'http://www.mccraymusic.com/assets/images/'+images[0],'id':'bg','alt':''}).appendTo('#bg-wrapper').parent().fadeIn(0);
$('.entersite').click(function(e) {
e.preventDefault();
var image = images[1];
$('#bg').parent().fadeOut(200, function() {
$('#bg').attr('src', 'http://www.mccraymusic.com/assets/images/'+image);
$(this).fadeIn(1000);
});
$(this).fadeOut(1000, function() {
$(this).remove();
});
});
});​
DEMONSTRATION
Also added :
display: block;
margin-left: auto;
margin-right: auto;
to your #bg element to center the image.

Alright, assuming you use JQuery
You have #backgroundid and #imageid
Begin by setting
$('#backgroundid').css('opacity',1);
$('#imageid').css('opacity',0); // setting opacity (transparency) to 0, invisible
Now you have #buttonid.
Set up a jquery event so that when it's clicked, you fade out the background, and fade in the image using JQuery's animate.
$('#buttonid').click(function() {
$('#backgroundid').animate(function() {
opacity : 0 // fade it to 0 opacity, invisible
}, 1000); // animation will take 1000ms, 1second
$('#imageid').animate(function() {
opacity : 1 // fade it to full opacity, solid
}, 1000);
});
Now about that image centering.
You can either let css manage it with
body { /* Body or #imageid parent */
text-align : center;
}
#imageid {
margin: 0px auto;
}
Or you can stick to a JQuery solution, using absolute/fixed positioning.
First, use some css to fix the position of your image
#imageid {
position: absolute; // or fixed, if you want
}
Now use JQuery to reposition it
function positionImage() {
var imagewidth = $('#imageid').width();
var imageheight = $('#imageid').height();
$('#imageid').css('left', ($(window).width() - imagewidth) / 2);
$('#imageid').css('top', ($(window).height() - imageheight) / 2);
}
$(document).ready(positionImage); // bind the ready event to reposition
$(window).resize(positionImage); // on window resize, reposition image too

if you keep a div element with height and width as 100% and bgcolor as black. And then change the opacity of the div as desired to get the fade in/out effect, that should generate the same effect. I guess..

You are better off using any available jQuery plugin as they would have optimized and fixed bugs for multiple browsers.
Try lightBoxMe plugin
http://buckwilson.me/lightboxme/
This is the simplest plugin available!