I am playing with a new website I created a few days ago.
The site contains lots and lots of gifs there is displayed on the frontpage. As of right now, a static .png thumbnail is showed and when hovered, it displays the gif instead.
This is pretty much what I want. However, as of now, the site preloads every single gif on the page, which takes a long time and a lot traffic is wasted. If there are 50 gifs on the frontpage and every gif is 2mb, that's 100mb traffic per user.
Isn't it possible to only load every png, then load the gif if it's hovered? I know it won't play smooth the first time, but I don't have a whole lot of web traffic on my web hotel.
Is this possible with either some PHP or good-old JavaScript?
Thanks
Change the URL of the image with hover. In this case with jQuery
$('#my_image').hover(function(){
$('#my_image').attr('src','my.gif');
});
Want to make it dynamic without having to set it per image? Add the HTML5 Data element:
<img src="my.png" data-gif="my.gif" />
And with JavaScript:
$('img').hover(function(){
$(this).attr('src',$(this).data('gif'));
});
You can add the HTML that contains the GIFs to the DOM after page load, inserting it as a string or using AJAX.
Another viable solution is to use CSS sprites and eliminate all those images by combining them into a larger one.
You're thinking about it the wrong way. Browsers don't request images unless you include the images in your page. You shouldn't try to prevent included images from being loaded, you should simply not include the images in the first place.
Remove the image URL from your code. In whatever code you have that currently makes the hidden image visible, you can set the URL as well.
Are the file names the same except for the extension? If so I would recommend this approach
Stop a gif animation onload, on mouseover start the activation
What you would do different is replace the .png with .gif this will load the gif on hover instead of at page load. Right now it sounds like you are loading both the .png and the .gif in a hidden div.
Edit:
Then on mouseout you would switch the source back to the .png.
Related
I want to preload all images on my page.
My page has some images used directly as links, i.e. as img tags within an a tag, as well as some images which are in the background-image property of some spans.
What's the best way to preload them all? I notice that a lot of the preload scripts seem to assume that the images will be loaded within image tags. For example, I've implemented this script: http://www.javascriptkit.com/javatutors/preloadimagesplus.shtml
But it doesn't make a difference on my page where certain spans when hovered over should have a new background. There's still a pause on my page when the user hovers over an element, before the right images background shows up.
Edit
I know about using sprites, my question is asking for a solution apart from sprites.
The following jQuery plugin was featured on http://www.unheap.com a while ago. Could this be of service?
http://nick-jonas.github.io/imageloader/
I do notice that the Github repository is "unavailable due to DMCA takedown", but maybe it could point you in the right direction.
Another solution might be this plugin:
https://github.com/sebarmeli/JAIL
This is basically a design question.
Preface
I have a web page which shows a list of thumbnails. The number of images can be anything, maybe hundreds.
What I need to do is this?
Get the number of total thumbnails.
Get the web url for each image.
Load each thumbnail into a box (div) and add each box dynamically to
scrollable container div.
User should be able to interact with the boxes ASAP.
I have other AJAX calls happening in the page.
The default method, set the src to each box and add it to the container. When loading stops, the image shows. The problem is that, all these image loading will hog the network and my other AJAX calls may timeout, which I can't allow. Also, the user should see the page as loading complete (loading bar should not show activity).
My Solution
The solution I have come up is this:
Use a local image as space holder.
Set the src of all the boxes as local image.
Change the src for first image to the web url.
When onload of the image fires, change the src of next image and so on.
Pros:
Only one image will be loading at a time.
User will be able to interact with the boxes.
Cons:
Only one image at a time may be a waste of bandwidth (what about 5 images at a time?)
What happens if user scrolls to the end, the images won't show up until all the other images have loaded.
Your opinion
I need expert opinions on how to improve this solution.
Requirements:
Some bandwidth should be available for other AJAX calls
User should be able to interact with the page.
Questions:
Is this solution having any other issues?
Is this cross browser?
Am I correct in saying this will not affect the other AJAX calls?
I have a bunch of images held on a third party server that I want to load and display as thumbnails on a webpage...
Can I use JavaScript to load each image, crop and resize them to all be the same size, then display them in a grid on the page?
Ideally, I'd like to be able to do it client side. I don't really want to pre-load and process them on the server as I do not want to increase bandwidth usage..
You can put each image inside a block container with fixed dimensions and overflow: hidden, thus effectively cropping them (you can also position the image inside the container with negative top and left values to select which part of the image will be visible). All of this is standard CSS fare. The same goes for displaying the elements in a grid layout. See an example.
However, be advised that this kind of solution, although it requires almost no preparation, can be deceptively easy to follow. The user will still have to download the full, uncropped image for every cropped element you show in the page, which could turn out to be many MBs of data.
Depending on what your use case is, it might be far more preferable to adopt a server-side solution that pre-processes the images.
Maybe this is not exactly Javascript or Jquery based solution, but this script can help a lot on eCommerce websites or other types of sites where pages are full of thumbnails. It have cache mechanism, so images are processed only once:
http://shiftingpixel.com/2008/03/03/smart-image-resizer/
JS can't directly crop/resize an image, unless you're using a <canvas> tag. At most it can fake a crop by putting the image into another element with overflow:hidden and adjusting offsets/boundaries. You can fake a resize by setting the image's height/width/zoom CSS attributes.
But if you're concerned about bandwidth, consider that a client-side resizer requires the client to load a full-sized image from your server, BEFORE it can do any kind of adjustments on it.
Javascript is a client sided language. So the images must be downloaded first before javascript can control them. If you're loading a lot of images it's best to make a server sided script that crops the images before loading them.
I have so many images in a slide show and I need serve this slide show on mobile Safari. I noticed that whenever the page loads it gets stuck for some time until all images get loaded.
I decided to load images with a click event when ever I need them for specific action instead of appending all images directly into the HTML.
I want to use image pre-loading script and then I will add the image depending on the user action.
Will image pre-loading effect the page load time, or will this help me to improve the page load time and adding images as needed?
Also do let me know if there is any other way to achieve it. My goal is to load the page faster and also want to add images as needed which will not effect the animation quality and image rendering.
Image loading script
https://web.archive.org/web/1/http://articles.techrepublic%2ecom%2ecom/5100-10878_11-5214317.html
Use CSS:
a:hover {
background:url("menu2.gif") left top no-repeat;
}
I have an image on a webpage and when the user hovers over it, another image appears. When then hovering over the appearing image, it flickers.
Anybody any idea why that is?
Tony
UPDATE: The first image does not dissapear when hovering, just another (smaller) image appears over the top in the left top corner. When now moving over that smaller image, then the flicker appears.
The image on the site is part of a gallery, so it's a php variable and gets loaded when a user selects from a list of images. So embedding one into the other is very hard.
Because the browser is fetching the new image. The best solution is to incorporate both images into one, and either purely use CSS to change the background-position on :hover, or ( for IE6 and non-anchor elements ) change the background position with JS.
In IE? IE is notorious for not caching images that are loaded dynamically (either with CSS :hover or due to Javascript events). You can use CSS sprites (basically, using one image file to display both images, and using positioning to show one or the other; tutorial, linked by Mike Robinson), or you can use image preloading:
var preloadImg = document.createElement('img');
preloadImg.src = 'path/to/image';
Edit: and other browsers will do the same on first load. IE just may continue to do it on every switch.
If I understand you right, you probably replace the src of your image every time the mouseover event is fired. So, even when your image is replaced, your event is fired and the image is replaced with itself, which may cause flickering.
I guess you're probably using IE. This is a bug with the way it implements caching in some versions. You fix it by either configuring your web server to send proper cache headers, or by using CSS sprites. I recommend the latter, as that means less HTTP requests, and the preloading works even without JS.