How to change images in flexslider? - javascript

I know this is a very basic question but it has me very confused - there's not much documentation that I could find about the flexslider. Also, I'm very new to this language, I'm a C++ / ASM type person but trying to get a webpage setup. The page is for an internet radio station. The slider is used to show the album covers of the currently playing, next, and later albums. The image names are 'hard-coded' in the slider which is fine if the images don't need to change. The problem is that the images do change every 3 minutes but the browser caches them so even if the image file contents change, the old image data displays.
I spent the last few weeks developing a Windows service that updates the actual image files (Playing.jpg, Next.jpg, etc.) from the SQL database (among other things) only to find out once the slider is initialized, the displayed images don't change.
Anyway, is the slider just used for 'static' images? Any advice as to how to update the images dynamically? php / js?
<li> <img src="Playing.jpg" alt="" >
<div class="flex-caption">
<h2>Now Playing</h2>
</div>
</li>
Thank you!
Keeping the filenames the same but changing the image contents makes no difference. What's the general way of changing slider images dynamically? Code snippets would be appreciated.

To avoid the browser cache you can add a random query like that:
PHP:
<li> <img src="Playing.jpg?v=<?php echo rand(); ?>" alt="" >
<div class="flex-caption">
<h2>Now Playing</h2>
</div>
</li>
JS:
<li> <img src="Playing.jpg" alt="" id="imageid">
<div class="flex-caption">
<h2>Now Playing</h2>
</div>
</li>
<script>
document.getElementById("imageid").src="Playing.jpg?v="+Math.random();
</script>

Mehedi's answer is good but random strings can collide and Math.random() is returning a float, an integer would be better.
So, it is better to use server current UNIX time e.g.:
PHP
<li>
<img src="Playing.jpg?v=<?php echo time(); ?>" alt="" />
<div class="flex-caption">
<h2>Now Playing</h2>
</div>
</li>
JavaScript
document.getElementById("imageid").src = `Playing.jpg?v=${Date.now()}`;
document.getElementById("imageid").alt = `Image Name: Playing.jpg?v=${Date.now()}`;
<li>
<img src="Playing.jpg" alt="" id="imageid" />
<div class="flex-caption">
<h2>Now Playing</h2>
</div>
</li>
However, this is bad for the user as he is always downloading images. The best solution would be to change the filenames from database and pass that data somehow to your code (maybe an API endpoint or something).
Also, since images are changing every 3 minutes, you could set a cookie in localStorage and check with it for intervals of 3 minutes before passing another time in your <img>.
Personally, I would go with an API-approach.

Related

How to stop lightbox from advancing to next gallery?

I am totally new to js and stuff like that, but I was made an admin and editor of an existing webpage of my employer. The problem is, I cannot contact a man, who has written the webpage, so its sometimes pretty hard to find out the paths and solutions of problems.
The problem I want to solve is on the page using Lightbox for image gallery. When you click on the first image, it pops out and works brilliant. But when you come to the end of the gallery, you can continue to the next car.
Here is the link to show what I mean: http://bmw-groupm.sk/vozidla-na-sklade/
Can you please at least try to tell me, if the problem is in CSS or script itself? Thank you.
It is not that simple. Cars are added to the webpage by separate Admin panel, which creates a directory on server, puts the images inside and than the car content is called by some complex process. See the html:
$adresar[$cislo] = opendir("vehicles/".$cisl[$cislo]."/");
while ($subor[$cislo] = readdir($adresar[$cislo])){
if ($subor[$cislo]!="." && $subor[$cislo]!=".." && !is_dir($subor[$cislo]) && $subor[$cislo]!="t" && $subor[$cislo]!="tn" && $subor[$cislo]!="mcith") {
$ext[$cislo] = pathinfo($subor[$cislo], PATHINFO_EXTENSION);
$ext[$cislo] = strtolower($ext[$cislo]);
if ($ext[$cislo]!="pdf") {
list($w[$cislo], $h[$cislo], $type[$cislo], $attr[$cislo]) = getimagesize("vehicles/".$cisl[$cislo]."/".$subor[$cislo]);
if ($w[$cislo]<$h[$cislo]) {
$iclass="imgh";
}
else {
$iclass="imgw";
}
$pas[$cislo].='<a rel="group" href="/vehicles/'.$cisl[$cislo].'/'.$subor[$cislo].'"><img src="/vehicles/'.$cisl[$cislo].'/'.$subor[$cislo].'"></a>';
} else {
$docu[$cislo]="/vehicles/".$cisl[$cislo]."/".$subor[$cislo];
}
}
}
The images are placed in links, which have the same rel="group" attribute.
Change these such that each car/gallery group of images has a different value from the next.
For example, car 1 gallery images will be rel="group1", and car 2 images will berel="group2".
You have to create an image set and give a specific name. The details are found here in the official website.
Documentation
You have to create an image set and give a specific name. You can provide the name in the data-lightbox attribute. You can find an example with dummy image links below.
<p>Gallery One</p>
<a href="https://dummyimage.com/600x400/b0a4b0/ffffff" data-lightbox="car">
<img src="https://dummyimage.com/600x400/b0a4b0/ffffff" />
</a>
<a href="https://dummyimage.com/600x400/ff00ff/ffffff" data-lightbox="car">
<img src="https://dummyimage.com/600x400/ff00ff/ffffff" />
</a>
<a href="https://dummyimage.com/600x400/ed1520/ffffff" data-lightbox="car">
<img src="https://dummyimage.com/600x400/ed1520/ffffff" />
</a>
<p>Gallery Two</p>
<a href="https://dummyimage.com/600x400/17a621/ffffff" data-lightbox="jeep">
<img src="https://dummyimage.com/600x400/17a621/ffffff" />
</a>
<a href="https://dummyimage.com/600x400/0e2796/ffffff" data-lightbox="jeep">
<img src="https://dummyimage.com/600x400/0e2796/ffffff" />
</a>
<a href="https://dummyimage.com/600x400/616011/ffffff" data-lightbox="jeep">
<img src="https://dummyimage.com/600x400/616011/ffffff" />
</a>
The details are found here on the official website.

ng repeat alter with media queries and screen size

I have a JSon file that is meant to resemble that of a Youtube collection of info.
As such there are several img urls of varying sizes.
I'm currently listing the images in my html using an ng-repeat and directing to a specific image size.
What would be the recommended method to alter the path of this ng-repeat depending upon the screen size (media queries)
<div class="video-list">
<div class="scrollbar scroll-y">
<div data-ng-repeat="video in videos"class="list-items">
<ul>
<li>
<a href="#" data-ng-click="setVideo(video.snippet.resourceId.videoId, video.snippet.title, video.snippet.description)">
<img src="[[video.snippet.thumbnails.medium.url]]"/>
<h3><span>[[video.snippet.title| removeBrackets]]</span></h3>
</a>
</li>
</ul>
</div>
</div>
</div>
but i would like it to display [[video.snippet.thumbnails.default.url]] when the screen is at a specific size. I understand I'll probably need to make a filter or a function. I'm far too new to angular and javascript to understand the best practice.
Any guidance is greatly appreciated :)

How to swap between two images with one separate hyperlink ONLY

Been trying to find a solution to this but usually all methods involve mouse-hovering or mouse-clicking on the image itself rather than a hyperlink to swap the two images - or having to click on 4 separate links to view 4 different images for example.
<div id="aboutus">
<a href="#>More about us...</a>
<img id="introimage" src="images/img1.jpg" style="display:block">
<img id="introimage" src="images/img2.png" style="display:none"/>
</div>
Simply put I would like the 'More About Us' link to swap the display for the images when clicked - or any other method that would let me swap the two images on each click.
As I said in the comments, you should change the IDs so they're unique or make them classes (as I have done in this example).
HTML
<div id="aboutus">
More about us...
<img class="introimage" src="images/img1.jpg" style="display:block">
<img class="introimage" src="images/img2.png" style="display:none"/>
</div>
Javascript
$(function() {
$("a.introimagetoggle").on("click", function(event) {
event.preventDefault();
$("img.introimage").toggle();
});
});
You could mess about checking which image is visible and then setting the display state of each of them according to that, but toggle is simple and will suit this particular instance.

Using jQuery to Swap Out Body Background Image on click and randomize on load

I've got a body background image that is being "placed" by a plugin called ezBigResize that basically allows the image to scale with the browser window.
The designer wants to image though to be able to be swapped out by a series of thumbnails on the page, along with that image being randomized on page load from that series of images.
Initially before those two additions, I just had it setup like this:
$(document).ready(function() {$("body").ezBgResize({img : "/lib/img/bkgr/mainBG.jpg"});});
Then this is the code now (in a jQuery Tools scrollable)
<div id="bkgrSelector">
<div class="scrollNav">
<a class="prev browse left"></a>
</div>
<div class="scrollable">
<div class="items">
<img src="/lib/img/bkgr/selections/main-bg.jpg" width="77" height="44" />
<img src="/lib/img/bkgr/selections/main-bg02.jpg" width="77" height="44" />
<img src="/lib/img/bkgr/selections/main-bg03.jpg" width="77" height="44" />
</div>
</div>
<div class="scrollNav">
<a class="next browse right"></a>
</div>
</div>
I'm a little over my head though to allow these to both randomize on page load and to swap out the image via the value in the href.
I tried something like this, but it didn't work and is obviously inclomplete. Plus, it doesn't address the randomization at all.
$('#bkgrSelector .items img[href]').click(function()
{
$("body").css("background-image", "url()");
});
Any ideas, help, etc. would be appreciated.
Are those <img> pointing at the full-sized image file? I absolutely LOATHE sites that use full-size images and shrink them to thumbnail size. The load times are attrocious.
If they're actually thumbnail-sized images, you won't be able to use that url directly as your background url, as you'd just be stretching a small thumbnail-sized image to cover the window and get a hideous pixelized mess.
If the page is being dynamically generated, you'd want to create a JS array that contains the URLs of the full-sized image urls, so that when a thumbnail is clicked, you can get the fullsize url from that array. Or at least have a standardized naming convention so a simple string manipulation lets you turn the thumbnail url into a fullsize image url.
Once you've got that array, it's a simple matter to randomize a choice from it:
var imgs = ['/url/for/img1.jpg', '/url/for/img2.jpg', etc....];
$(document).ready(function() {
randomUrl = imgs[Math.round(Math.random() * (imgs.length - 1)) + 1];
$("body").css("background-image", 'url(' + randomURL + ')');
});

Can you control the order in which images (hidden vs visible) on a web page are loaded?

If I have two divs, one shown, the other hidden, I want the images in the visible div to load first and only then for the other hidden images to load.
Is there a way to do this?
<div class="shown">
<img src="a.jpg" class="loadfirst">
<img src="b.jpg" class="loadfirst">
<img src="c.jpg" class="loadfirst">
<img src="d.jpg" class="loadfirst">
<img src="e.jpg" class="loadfirst">
</div
<div style="display:none" class="hidden">
<img src="1.jpg" class="loadsecond">
<img src="2.jpg" class="loadsecond">
<img src="3.jpg" class="loadsecond">
<img src="4.jpg" class="loadsecond">
<img src="5.jpg" class="loadsecond">
</div>
The browser should be requesting the images in the order that the markup lists them in. So it would ask for a.jpg, b.jpg, etc.
If you don't want the hidden DIV images to load with the page then you would have to insert that HTML from the client side once you want the images loaded.
As others have said, it all comes down to which images are listed first in the html markup.
But, something that may help with this problem is to display a loading spinner until all of your images are fully loaded.
You could do this with JQuery, as in this example.
http://jqueryfordesigners.com/image-loading/
Some, if not most, browsers do this automatically. If images are hidden then they are not downloaded.
If all the images are embedded within a single image map, then all images will load at the same time. That solves issue of the "literal load order". Thats a bit complicated though and a totally different issue that you might want to skip for now ( http://www.alistapart.com/articles/imagemap/ ).
But, for the "apparent load order" you start with a DIV with <DIV id="1" style="visibility: hidden"> option. Then use a for loop to change the visibility of the DIVs in order.
for (var=0;var<=10;var=var+increment) {
document.getElementById(var).style.visibility = 'visible';
}
Also, maybe an approach using layers: http://jennifermadden.com/javascript/dhtml/showHide.html
I think there are ways to dynamically load an additional CSS file (when you are ready to load images): http://www.hunlock.com/blogs/Howto_Dynamically_Insert_Javascript_And_CSS

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