There is an image element , how do I use this same img element without sending another request to the server. Its important to note, I don't want image1.jpg downloaded twice from the webserver. Any ideas?
function loadCarousels(carouselLoc, carouselId) {
$("li").find(carouselLoc).each(function (index) {
var img = this;
var outer = 0;
$(carouselId).find("ul").each(function (innerIndex) {
var liX = document.createElement("li");
$(this).append(liX);
var imgInner = document.createElement("img");
imgInner.src = img.src;
$(imgInner).appendTo(liX);
console.log($(this));
});
});
}
Is how I currently try but it doesn't work. it creates a separate image.
Browsers should be already pretty aggressive on caching images: Chrome often shows multiple requests, but if you check from the second on usually they're all satisfied using the cache.
In case you want to cache internally in your JS code, try to cache images by URL like the following:
// use this as JS cache
var images = {};
function loadCarousels(carouselLoc, carouselId) {
$("li").find(carouselLoc).each(function (index) {
var img = this;
var outer = 0;
// cache it
if(!images[img.src]){
images[img.src] = document.createElement("img");
// if the user disable the cache, this should prevent another request
images[img.src].src = img.src;
}
$(carouselId).find("ul").each(function (innerIndex) {
var liX = document.createElement("li");
$(this).append(liX);
// retrieve from the cache
var imgInner = images[img.src];
$(imgInner).appendTo(liX);
console.log($(this));
});
});
}
Related
I'm pretty new to JS and programming altogether so I'm sorry in advance if the explanation is a little sloppy, but I'll try to make it as clear as possible.
So what I'm trying to do is have a JS code that reads and displays (in an HTML page) photos from a PC folder, makes them clickable and on the click it redirects you to a page with the same photo but in high resolution.
Now, I have this piece of code that displays the said pictures, but the thing is I don't seem to be able to figure out how to "connect" it to the pictures and make them clickable. What makes it more difficult is that I'm trying to make all of this code dynamic (as you can see I've done in the below code), so I would like not to have any hardcoded titles of pictures and so on.
var index = 1;
var tempImg = new Image();
tempImg.onload = function(){
appendImage();
}
var tryLoadImage = function(index){
tempImg.src = 'img/' + index + '.jpg';
}
var appendImage = function(){
var img = document.createElement('img');
img.src = tempImg.src;
document.body.appendChild(img)
tryLoadImage(index++);
}
tryLoadImage(index);
Any help is very much appreciated, thank you very much!
You can make your images clickable by adding an onclick function to them. Try something like this:
var appendImage = function(){
var img = document.createElement('img');
img.src = tempImg.src;
img.onclick = e => {
// do something you want to show the full picture like this maybe
var el = document.getElementById("fullpictureid");
if (el && e.target.src) {
el.src = e.target.src;
// so that it sets "src" in <img id="fullpictureid"> for example
}
};
document.body.appendChild(img)
tryLoadImage(index++);
}
I have an array of URIs that represent .png elements, e.g., "./img/diamond-red-solid-1.png".
I want to assign each element of the array "gameDeck[0], gameDeck[1], etc. to div ids in HTML. Do I need to identify the elements as = SRC.IMG?
var gameDeck[];
var gameBoardCards = function () {
for (let cardArr of cardsToLoad)
gameDeck.push("./img/" + cardArr + ".png");
}
gameBoardCards();
document.addEventListener('DOM Content Loaded', function () {
gameDeck[0] = document.getElementById("card1");
gameDeck[1] = document.getElementById("card2");
etc.
});
The way I'm understanding your question is that you would like to target the divs in your HTML with ids of card1, card2, card3... card12 etc.
You would like to insert an img tag into each of these divs with the src being the URIs of the gameDeck array.
The following code achieves this. I've tested it and it works fine. Hope it helps :)
document.addEventListener('DOMContentLoaded', function () {
//iterate through the gameDeck array.
for (let x = 0;x < gameDeck.length;x++){
//create an img tag for each gameDeck element
var imgElement = document.createElement("img");
//set the source of the img tag to be the current gameDeck element (which will be a URI of a png file)
imgElement.src = gameDeck[x];
//target the div with id "card(x + 1)"
var cardID = "card" + (x + 1);
var cardElement = document.getElementById(cardID);
//append the img tag to the card element
cardElement.appendChild(imgElement);
}
//log the HTML to the console to check it
console.log(document.getElementById('body').innerHTML);
});
Here is a way that you can either insert images as background images, or as <img /> elements into the divs you are referring to:
<div id="card0" style="width: 100px; height: 100px;"></div>
<div id="card1" style="width: 100px; height: 100px;"></div>
let loadedImage = [];
function preloadImages(urls, allImagesLoadedCallback) {
let loadedCounter = 0;
let toBeLoadedNumber = urls.length;
urls.forEach(function(url) {
preloadImage(url, function() {
loadedCounter++;
console.log(`Number of loaded images: ${loadedCounter}`);
if (loadedCounter == toBeLoadedNumber) {
allImagesLoadedCallback();
}
});
});
function preloadImage(url, anImageLoadedCallback) {
img = new Image();
img.src = url;
img.onload = anImageLoadedCallback;
loadedImage.push(img);
}
}
function gameBoardCards() {
for (let i = 0; i < loadedImage.length; i++) {
document.getElementById(`card${i}`).style.backgroundImage = `url('${loadedImage[i].src}')`;
// document.getElementById(`card${i}`).appendChild(loadedImage[i]);
}
}
preloadImages([
`https://upload.wikimedia.org/wikipedia/commons/thumb/7/7d/Color_icon_green.svg/2000px-Color_icon_green.svg.png`, `https://upload.wikimedia.org/wikipedia/commons/thumb/f/ff/Solid_blue.svg/225px-Solid_blue.svg.png`
], function() {
console.log(`all images were loaded`);
gameBoardCards();
// continue your code
});
It may seem like a bit much for what you are trying to accomplish, but I threw in a proper image-loading handler there. The preloadImages function will handle the loading of images, that way they are properly preloaded, and can render to the DOM. Often times, we try to use images before they are properly loaded, resulting in them sometimes not being displayed, despite no errors are being thrown.
The rest of the code is straight forward, in the for loop, it loops through the existing divs and you can either use the current active line document.getElementById(`card${i}`).style.backgroundImage = `url('${loadedImage[i].src}')`; to use the loadedImage[i] image src to load that as the divs's background image. Or you can use the commented-out line directly below that document.getElementById(`card${i}`).appendChild(loadedImage[i]); to insert an <img /> element into that div. Just use either one that works for you.
You can see the code in action in this JS Fiddle demo.
Hope this helps :)
I have website and now making a hybrid app for it.
I get all my blog post using Jquery get method.
However the issue is that <img src="/media/image.png"> is sometime relative url and sometime an absolute url.
Everytime an absolute url breaks the image showing 404 error.
How to write Jquery function to find if src is absolute and change it to
https://www.example.com/media/image.png
I will not be able to provide any code samples I have tried since I am not a front end developer and tried whole day solving it.
Note: I need to change images present only in <div id="details"> div.
You should always use same path for all the images, but as of your case you can loop through images and append the domain, as of the use case I have added the domain in variable you can change it as per your requirement.
You can use common function or image onload to rerender but I h
Note: image will rerender once its loaded.
var imageDomain = "https://homepages.cae.wisc.edu/~ece533/";
//javascript solution
// window.onload = function() {
// var images = document.getElementsByTagName('img');
// for (var i = 0; i < images.length; i++) {
// if (images[i].getAttribute('src').indexOf(imageDomain) === -1) {
// images[i].src = imageDomain + images[i].getAttribute('src');
// }
// }
// }
//jquery solution
var b = 'https://www.example.com';
$('img[src^="/media/"]').each(function(e) {
var c = b + $(this).attr('src');
$(this).attr('src', c);
});
//best approach you are using get request
//assuming you are getting this respone from api
var bArray = ["https://www.example.com/media/image.png", "/media/image.png"]
var imgaesCorrected = bArray.map(a => {
if (a.indexOf(b) === -1) {
a = b+a;
}
return a;
});
console.log(imgaesCorrected);
img {
width: 50px
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<img src="/media/image.png">
<img src="https://www.example.com/media/image.png">
document.querySelectorAll('#details img').forEach(img => {
const src = img.getAttribute('src');
// use regex, indexOf, includes or whatever to determine you want to replace the src
if (true) {
img.setAttribute('src', 'https://www.example.com' + src);
}
});
The best would be to do this with the response html from the ajax request before inserting into the main document so as to prevent needless 404 requests made while changing the src
Without seeing how you are making your requests or what you do with the response here's a basic example using $.get()
$.get(url, function(data){
var $data = $(data);
$data.find('img[src^="/media/"]').attr('src', function(_,existing){
return 'https://www.example.com' + existing
});
$('#someContainer').append($data)'
})
You can just get all the images from an object and find/change them if they don't have absolute url.
var images = $('img');
for (var i = 0 ; i < images.length ; i++)
{
var imgSrc = images[i].attributes[0].nodeValue;
if (!imgSrc.match('^http'))
{
imgSrc = images[i].currentSrc;
console.info(imgSrc);
}
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<img src="/media/test.jpg">
<img src="/media/test.jpg">
<img src="https://www.example.com/media/test.jpg">
I have this script which should show the text "Loading..." while images are loading, then change the text to "loaded" when all images are loaded. I added a button to load new images to make sure that it works for dynamically loaded images as well.
This works perfectly in Chrome but in Firefox the "Loading..." text never appears. I have no idea why this would be. The page begins loading and not all images are loaded so it should create the text "Loading.." but it doesn't. Then when all images are done loading the text "Loading" appears.
I just don't get why one message would appear and the other wouldn't. Especially because there are no qualifications that have to be met before creating the "Loading..." text, it should just fire automatically.
jsfiddle Example | Full Page Example
$(document).ready(function() {
var checkComplete = function() {
if($('img').filter(function() {return $('img').prop('complete');}).length == $('img').length) {
$('.status').text('Loaded');
} else {
$('.status').text('Loading...');
}
};
$('img').on('load',function() {
checkComplete();
});
$('#button').click(function() {
$('img.a').attr('src' , 'http://farm9.staticflickr.com/8545/8675107979_ee12611e6e_o.jpg');
$('img.b').attr( 'src' , 'http://farm9.staticflickr.com/8382/8677371836_651f586c99_o.jpg');
checkComplete();
});
checkComplete();
});
You have several issues in the code.
First off, the checkComplete() function is not written correctly. It should be this:
var checkComplete = function() {
var imgs = $('img');
if(imgs.filter(function() {return this.complete;}).length == imgs.length) {
$('.status').text('Loaded');
} else {
$('.status').text('Loading...');
}
};
The main fix here is that the filter callback needs to refer to this.complete, not to $('img').prop('complete') because you are trying to filter a single item at a time.
Second off, you are relying on both .complete and .load working correctly AFTER you've changed the .src value. This is explicitly one of the cases where they do not work properly in all browsers.
The bulletproof way to work around this is to create a new image object for the new images, set the onload handler before you set the .src value and when both onload handlers have fired, you will know that both new images are loaded and you can replace the once you have in the DOM with the new ones.
Here is a version that works in FF:
$(document).ready(function() {
$('#button').click(function() {
var imgA = new Image();
var imgB = new Image();
imgA.className = "a";
imgB.className = "b";
var loaded = 0;
imgA.onload = imgB.onload = function() {
++loaded;
if (loaded == 2) {
$("img.a").replaceWith(imgA);
$("img.b").replaceWith(imgB);
$('.status').text('Loaded');
}
}
// the part with adding now to the end of the URL here is just for testing purposes to break the cache
// remove that part for deployment
var now = new Date().getTime();
imgA.src = 'http://farm9.staticflickr.com/8545/8675107979_ee12611e6e_o.jpg?' + now;
imgB.src = 'http://farm9.staticflickr.com/8382/8677371836_651f586c99_o.jpg?' + now;
$('.status').text('Loading...');
});
});
Working demo: http://jsfiddle.net/jfriend00/yy7GX/
If you want to preserve the original objects, you can use the newly created objects only for preloading the new images and then change .src after they've been preloaded like this:
$(document).ready(function() {
$('#button').click(function() {
var imgA = new Image();
var imgB = new Image();
var loaded = 0;
imgA.onload = imgB.onload = function() {
++loaded;
if (loaded == 2) {
$("img.a")[0].src = imgA.src;
$("img.b")[0].src = imgB.src;
$('.status').text('Loaded');
}
}
// the part with adding now to the end of the URL here is just for testing purposes to break the cache
// remove that part for deployment
var now = new Date().getTime();
imgA.src = 'http://farm9.staticflickr.com/8545/8675107979_ee12611e6e_o.jpg?' + now;
imgB.src = 'http://farm9.staticflickr.com/8382/8677371836_651f586c99_o.jpg?' + now;
$('.status').text('Loading...');
});
});
Working demo of this version: http://jsfiddle.net/jfriend00/ChSQ5/
From the jQuery API .load method
Caveats of the load event when used with images
A common challenge developers attempt to solve using the `.load()` shortcut is to execute a function when an image (or collection of images) have completely loaded. There are several known caveats with this that should be noted. These are:
It doesn't work consistently nor reliably cross-browser
It doesn't fire correctly in WebKit if the image src is set to the same src as before
It doesn't correctly bubble up the DOM tree
Can cease to fire for images that already live in the browser's cache
This piece of code adds images to the DOM after dragging them into a div-element.
var showImage = function (ev) {
var file = ev.target.file;
var thumb = new Image(100,100);
thumb.src = ev.target.result;
thumb.className = 'thumbFoto';
thumb.title = file.name;
thumb.alt = file.name;
var anchor = document.createElement('a');
anchor.className = 'thumbLink';
anchor.href = ev.target.result;
anchor.rel = 'album1';
anchor.title = file.name;
anchor.appendChild(thumb);
dropZone.appendChild(anchor);
}
This code is linked to the page using
<script type="text/javascript" src="js/code.js"></script>
After the images are added to the webpage, I would like preview them using Fancybox.
When the page is loaded (before I dragged any image onto it), this script is executed in the html-header:
<script type="text/javascript">
$(document).ready(function() {
/* Apply fancybox to albums */
$("a.thumbLink").fancybox();
});
</script>
Now how do I make sure I can preview the recently added images using Fancybox?
I assume you use jQuery UI draggable object, you can call your fancybox on stop() event of your draggable object, like this:
$( ".selector" ).draggable({
stop: function( event, ui ) {
$("a.thumbLink").fancybox();
}
});
EDIT:
Based on your code you can simply put your fancybox caller in function of showFileInList, like this:
var showFileInList = function (ev) {
var file = ev.target.file;
if(document.getElementById("fileDropText")){
var textToBeRemoved = document.getElementById("fileDropText");
var imageToBeRemoved = document.getElementById("fileDropImg");
textToBeRemoved.parentElement.removeChild(textToBeRemoved);
imageToBeRemoved.parentElement.removeChild(imageToBeRemoved);
}
var thumb = new Image(100,100);
thumb.src = ev.target.result;
// var thumb = createThumb(ev.target.result);
thumb.className = 'thumbFoto';
thumb.title = file.name;
thumb.alt = file.name;
var anchor = document.createElement('a');
anchor.className = 'thumbLink';
anchor.href = ev.target.result;
anchor.rel = 'album1';
anchor.title = file.name;
// anchor.addEventListener("click", showImagePreview, false);
anchor.appendChild(thumb);
// fileList.insertBefore(anchor, dropZone);
dropZone.appendChild(anchor);
// show fancybox
$("a.thumbLink").fancybox({type: "inline", href: "#fileDrop"});
}
See working code HERE
Try routing all of your DOM changes through a single object using the "Chain of Responsibility" pattern. That way the object can keep track of any changes to the dom. Then I would use ConversationJS to fire a function that does whatever you want on DOM change: https://github.com/rhyneandrew/Conversation.JS