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++);
}
Is there anyway that I can put an image on my site that changes.
I know how to change the source of an image element. What I mean is like:
the image is located here
http://mywebsite.com/image.png
this doesn't change but I want the actual image to change.
More examples:
https://huggle.jdf2.org/
This site creates a bbcode element that contains the img username.png
[url=http://huggle.jdf2.org/hug/username][img]http://huggle.jdf2.org/sig/username.png[/img][/url]
This image changes depending on how many huggles you have.
How would I do this?
You can dynamically set the image source URL with:
var yourURLHere = 'ADD YOUR URL HERE';
image.src = yourURLHere;
If you want the your image to randomly change, you can use Math.random() to select a random URL from an array.
Example: Random teddy bear images (see below).
<image src="#" id="my-image"/>
Click to change image randomly.
<button id="my-btn">Change it!</button>
<script>
var imageURLs = [
'https://s-media-cache-ak0.pinimg.com/originals/4e/da/9f/4eda9f56de08463bcc18d154f654ab6d.jpg',
'http://lcdn.inthelighturns.com/media/product/e85/sweet-memories-blue-teddy-bear-urn-b83.jpg',
'https://s-media-cache-ak0.pinimg.com/originals/3c/80/3c/3c803ce72e8c0325d7ea0fcd32f81ed9.jpg',
'http://cliparting.com/wp-content/uploads/2016/07/Cartoon-teddy-bear-clipart.gif',
'http://cliparts.co/cliparts/rcn/Kox/rcnKox65i.png',
'https://s-media-cache-ak0.pinimg.com/originals/f2/d6/25/f2d6258ef0fa6de2160778066ccec832.jpg',
'https://s-media-cache-ak0.pinimg.com/236x/90/3a/6c/903a6c59c0a2f42e7d6e7cb9427a8337.jpg',
'https://s-media-cache-ak0.pinimg.com/564x/a9/ee/30/a9ee30a4f8d196a111aa5c3db7b13b6e.jpg',
'http://cdn3.volusion.com/9nxdj.fchy5/v/vspfiles/photos/BB-1433-2.jpg?1415360799'
];
var image = document.getElementById('my-image');
function pickRandomURL() {
return imageURLs[Math.floor(Math.random() * imageURLs.length)];
}
image.src = pickRandomURL();
image.width = 200;
var btn = document.getElementById('my-btn');
btn.onclick = function() {
image.src = pickRandomURL();
image.width = 200;
};
</script>
I have created a webpage that basically displays 2 images side by side.
It has a "download" button, which triggers a vanilla Javascript function, which creates a <canvas> HTML element and concatenates the two images inside of it. It then creates a link with the base64-encoded result image as href and clicks on it:
<a download="image.png" id="dllink" href="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAABQAAAAMnCAYAAABhnf9DAAAgAElEQVR4nOzdR48kD3rn96j03pfv6qo21dVd3qT3JryP9Jll281..."></a>
Here is what the function I'm using looks like:
/**
* Create canvas, draw both images in it, create a link with the result
* image in base64 in the "href" field, append the link to the document,
* and click on it
*/
function saveImage() {
// Get left image
var imgLeft = new Image();
imgLeft.setAttribute('crossOrigin', 'anonymous');
imgLeft.src = "imgleft/" + idxImageShownLeft + ".jpg";
imgLeft.onload = function() {
// Once the left image is ready, get right image
var imgRight = new Image()
imgRight.setAttribute('crossOrigin', 'anonymous');
imgRight.src = "imgright/" + idxImageShownRight + ".jpg";
imgRight.onload = function() {
// Once the right image is ready, create the canvas
var canv = document.createElement("canvas");
var widthLeft = parseInt(imgLeft.width);
var widthRight = parseInt(imgRight.width);
var width = widthLeft + widthRight;
var height = imgLeft.height;
canv.setAttribute("width", width);
canv.setAttribute("height", height);
canv.setAttribute("id", "myCanvas");
canv.setAttribute('crossOrigin', 'anonymous');
var ctx = canv.getContext("2d");
// Draw both images in canvas
ctx.drawImage(imgLeft, 0, 0);
ctx.drawImage(imgRight, widthLeft, 0);
// Create PNG image out of the canvas
var img = canv.toDataURL("image/png");
// Create link element
var aHref = document.createElement('a');
aHref.href = img;
aHref.setAttribute("id", "dllink");
aHref.download = "image.png";
// Append link to document
var renderDiv = document.getElementById("render");
renderDiv.replaceChild(aHref, document.getElementById("dllink"));
// Click on link
aHref.click();
}
}
}
My problem is that this works fine on Firefox, but not on Chrome.
After a bit of investigating, I realized that by setting a breakpoint before the aHref.click(); line in Chrome, it worked fine. I think that it means that the aHref.click(); is called before the <a href="data:image/png;base64,...></a> is ready to be clicked, but I don't know for sure.
I couldn't find a duplicate of this topic. What keywords should I use just to be 100% sure?
Am I investigating in the right direction?
Is there an event I could rely on in order to call aHref.click(); only when it is ready?
You could wrap it in an init function that gets called when the window completes loading.
function init() {
aHref.click();
}
window.onload = init;
Its similar to the vanilla equivalent of jQuery's .ready() method.
aHref , document.getElementById("dllink") appear to be same element ? Though "dllink" has not yet been appended to document when .replaceChild called ?
Try substituting
renderDiv.appendChild(aHref);
for
renderDiv.replaceChild(aHref, document.getElementById("dllink"));
I have a canvas element with a drawing in it, and I want to create a button that when clicked on, it will save the image as a png file. So it should open up the save, open, close dialog box...
I do it using this code
var canvas = document.getElementById("myCanvas");
window.open(canvas.toDataURL("image/png"));
But when I test it out in IE9, a new window opens up saying "the web page cannot be displayed"
and the url of it is:
data:image/png;base64,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
Anyone know how to fix this?
try this:
var canvas = document.getElementById("alpha");
var dataURL = canvas.toDataURL("image/png");
var newTab = window.open('about:blank','image from canvas');
newTab.document.write("<img src='" + dataURL + "' alt='from canvas'/>");
This shows image from canvas on new page, but if you have open popup in new tab setting it shows about:blank in address bar.
EDIT:- though window.open("<img src='"+ canvas.toDataURL('image/png') +"'/>") does not work in FF or Chrome, following works though rendering is somewhat different from what is shown on canvas, I think transparency is the issue:
window.open(canvas.toDataURL('image/png'));
FileSaver.js should be able to help you here.
var canvas = document.getElementById("my-canvas");
// draw to canvas...
canvas.toBlob(function(blob) {
saveAs(blob, "pretty image.png");
});
To accomodate all three points:
button
save the image as a png file
open up the save, open, close dialog box
The file dialog is a setting in the browser.
For the button/save part assign the following function, boiled down from other answers, to your buttons onclick:
function DownloadCanvasAsImage(){
let downloadLink = document.createElement('a');
downloadLink.setAttribute('download', 'CanvasAsImage.png');
let canvas = document.getElementById('myCanvas');
let dataURL = canvas.toDataURL('image/png');
let url = dataURL.replace(/^data:image\/png/,'data:application/octet-stream');
downloadLink.setAttribute('href', url);
downloadLink.click();
}
Example on Codepen
Another, somewhat cleaner, approach is using Canvas.toBlob():
function DownloadCanvasAsImage(){
let downloadLink = document.createElement('a');
downloadLink.setAttribute('download', 'CanvasAsImage.png');
let canvas = document.getElementById('myCanvas');
canvas.toBlob(function(blob) {
let url = URL.createObjectURL(blob);
downloadLink.setAttribute('href', url);
downloadLink.click();
});
}
Example on Codepen
Neither solution is 100% cross browser compatible, so check the client
I used this solution to set the file name:
HTML:
Download!
<canvas id="canvas"></canvas>
JavaScript:
function download(){
document.getElementById("downloader").download = "image.png";
document.getElementById("downloader").href = document.getElementById("canvas").toDataURL("image/png").replace(/^data:image\/[^;]/, 'data:application/octet-stream');
}
I had this problem and this is the best solution without any external or additional script libraries:
In Javascript tags or file create this function:
We assume here that canvas is your canvas:
function download(){
var download = document.getElementById("download");
var image = document.getElementById("canvas").toDataURL("image/png")
.replace("image/png", "image/octet-stream");
download.setAttribute("href", image);
}
In the body part of your HTML specify the button:
<a id="download" download="image.png"><button type="button" onClick="download()">Download</button></a>
This is working and download link looks like a button. Tested in Firefox and Chrome.
I maybe discovered a better way for not forcing the user to right click and "save image as". Live draw the canvas base64 code into the href of the link and modify it so the download will start automatically. I don't know if it's universally browser compatible, but it should work with the main/new browsers.
var canvas = document.getElementById('your-canvas');
if (canvas.getContext) {
var C = canvas.getContext('2d');
}
$('#your-canvas').mousedown(function(event) {
// feel free to choose your event ;)
// just for example
// var OFFSET = $(this).offset();
// var x = event.pageX - OFFSET.left;
// var y = event.pageY - OFFSET.top;
// standard data to url
var imgdata = canvas.toDataURL('image/png');
// modify the dataUrl so the browser starts downloading it instead of just showing it
var newdata = imgdata.replace(/^data:image\/png/,'data:application/octet-stream');
// give the link the values it needs
$('a.linkwithnewattr').attr('download','your_pic_name.png').attr('href',newdata);
});
You can wrap the <a> around anything you want.
Submit a form that contains an input with value of canvas toDataURL('image/png') e.g
//JAVASCRIPT
var canvas = document.getElementById("canvas");
var url = canvas.toDataUrl('image/png');
Insert the value of the url to your hidden input on form element.
//PHP
$data = $_POST['photo'];
$data = str_replace('data:image/png;base64,', '', $data);
$data = base64_decode($data);
file_put_contents("i". rand(0, 50).".png", $data);
Try this:
jQuery('body').after('<a id="Download" target="_blank">Click Here</a>');
var canvas = document.getElementById('canvasID');
var ctx = canvas.getContext('2d');
document.getElementById('Download').addEventListener('click', function() {
downloadCanvas(this, 'canvas', 'test.png');
}, false);
function downloadCanvas(link, canvasId, filename) {
link.href = document.getElementById(canvasId).toDataURL();
link.Download = filename;
}
You can just put this code in console in firefox or chrom and after changed your canvas tag ID in this above script and run this script in console.
After the execute this code you will see the link as text "click here" at bottom of the html page. click on this link and open the canvas drawing as a PNG image in new window save the image.
Full Working HTML Code. Cut+Paste into new .HTML file:
Contains Two Examples:
Canvas in HTML file.
Canvas dynamically created with Javascript.
Tested In:
Chrome
Internet Explorer
*Edge (title name does not show up)
Firefox
Opera
<!DOCTYPE HTML >
<html lang="en">
<head>
<meta charset="UTF-8">
<title> #SAVE_CANVAS_TEST# </title>
<meta
name ="author"
content="John Mark Isaac Madison"
>
<!-- EMAIL: J4M4I5M7 -[ＡＴ]- Hotmail.com -->
</head>
<body>
<div id="about_the_code">
Illustrates:
<ol>
<li>How to save a canvas from HTML page. </li>
<li>How to save a dynamically created canvas.</li>
</ol>
</div>
<canvas id="DOM_CANVAS"
width ="300"
height="300"
></canvas>
<div id="controls">
<button type="button" style="width:300px;"
onclick="obj.SAVE_CANVAS()">
SAVE_CANVAS ( Dynamically Made Canvas )
</button>
<button type="button" style="width:300px;"
onclick="obj.SAVE_CANVAS('DOM_CANVAS')">
SAVE_CANVAS ( Canvas In HTML Code )
</button>
</div>
<script>
var obj = new MyTestCodeClass();
function MyTestCodeClass(){
//Publically exposed functions:
this.SAVE_CANVAS = SAVE_CANVAS;
//:Private:
var _canvas;
var _canvas_id = "ID_OF_DYNAMIC_CANVAS";
var _name_hash_counter = 0;
//:Create Canvas:
(function _constructor(){
var D = document;
var CE = D.createElement.bind(D);
_canvas = CE("canvas");
_canvas.width = 300;
_canvas.height= 300;
_canvas.id = _canvas_id;
})();
//:Before saving the canvas, fill it so
//:we can see it. For demonstration of code.
function _fillCanvas(input_canvas, r,g,b){
var ctx = input_canvas.getContext("2d");
var c = input_canvas;
ctx.fillStyle = "rgb("+r+","+g+","+b+")";
ctx.fillRect(0, 0, c.width, c.height);
}
//:Saves canvas. If optional_id supplied,
//:will save canvas off the DOM. If not,
//:will save the dynamically created canvas.
function SAVE_CANVAS(optional_id){
var c = _getCanvas( optional_id );
//:Debug Code: Color canvas from DOM
//:green, internal canvas red.
if( optional_id ){
_fillCanvas(c,0,255,0);
}else{
_fillCanvas(c,255,0,0);
}
_saveCanvas( c );
}
//:If optional_id supplied, get canvas
//:from DOM. Else, get internal dynamically
//:created canvas.
function _getCanvas( optional_id ){
var c = null; //:canvas.
if( typeof optional_id == "string"){
var id = optional_id;
var d = document;
var c = d.getElementById( id );
}else{
c = _canvas;
}
return c;
}
function _saveCanvas( canvas ){
if(!window){ alert("[WINDOW_IS_NULL]"); }
//:We want to give the window a unique
//:name so that we can save multiple times
//:without having to close previous
//:windows.
_name_hash_counter++ ;
var NHC = _name_hash_counter ;
var URL = 'about:blank' ;
var name= 'UNIQUE_WINDOW_ID' + NHC;
var w=window.open( URL, name ) ;
if(!w){ alert("[W_IS_NULL]");}
//:Create the page contents,
//:THEN set the tile. Order Matters.
var DW = "" ;
DW += "<img src='" ;
DW += canvas.toDataURL("image/png");
DW += "' alt='from canvas'/>" ;
w.document.write(DW) ;
w.document.title = "NHC"+NHC ;
}
}//:end class
</script>
</body>
<!-- In IE: Script cannot be outside of body. -->
</html>
I really like Tovask's answer but it doesn't work due to the function having the name download (this answer explains why). I also don't see the point in replacing "data:image/..." with "data:application/...".
The following code has been tested in Chrome and Firefox and seems to work fine in both.
JavaScript:
function prepDownload(a, canvas, name) {
a.download = name
a.href = canvas.toDataURL()
}
HTML:
Download
<canvas id="canvasId"></canvas>
My solution via vue and async support
async downloadImage () {
const canvas = this.$refs.canvas
const blob = await new Promise(resolve => canvas.toBlob(resolve))
const downloadLink = document.createElement('a')
downloadLink.href = window.URL.createObjectURL(blob)
downloadLink.download = 'mycanvasimage.png'
downloadLink.click()
}
var canvasId = chart.id + '-canvas';
var canvasDownloadId = chart.id + '-download-canvas';
var canvasHtml = Ext.String.format('<canvas id="{0}" width="{1}" height="{2}"></canvas><a id="{3}"/>',
canvasId,
chart.getWidth(),
chart.getHeight(),
canvasDownloadId);
var canvasElement = reportBuilder.add({ html: canvasHtml });
var canvas = document.getElementById(canvasId);
var canvasDownload = document.getElementById(canvasDownloadId);
canvasDownload.href = chart.getImage().data;
canvasDownload.download = 'chart';
canvasDownload.click();
I'm trying to swap two images in two divs on click event, so that 22a.jpg ends up in div#second and 22b.jpg ends up in div#first, but every time I click the "swap" button I get this error in Firebug: imgArray[2].src is undefined. I tried to run the code in Chrome 17.0.963.2 and IE 8.0, and it works just fine with no errors. I'm using Firefox 11.0
HTML
<body>
<div id = "first" class = "thumbnail">
<img class = "thumbsize" src = "22a.jpg" />
</div>
<div id = "second" class = "thumbnail">
<img class = "thumbsize" src = "22b.jpg" />
</div>
<input type = "button" id = "swap" value = "swap" />
</body>
JS
<script type = "text/javascript">
document.getElementById("swap").onclick = function(){
if(document.images){
var imgArray = document.images;
imgArray[2] = new Image();
imgArray[2].src = imgArray[0].src;
imgArray[0].src = imgArray[1].src;
imgArray[1].src = imgArray[2].src;
}
};
</script>
document.images is readonly in Firefox (link to specification). You can create a new image, but you can't append it to the document.images array.
A better way to accomplish image swapping would look something like this:
document.getElementById("swap").onclick = function(){
if(document.images){
var imgArray = document.images;
var tempSrc = imgArray[0].src;
imgArray[0].src = imgArray[1].src;
imgArray[1].src = tempSrc;
}
};
You only have two images in your HTML so imgArray[2] is not defined. Use a temp var to swap the other images.
Have you tried putting it in some sort of ready-function?
$('button#swap').toggle(function() {
$("div#first > img").attr('src','22b.jpg');
$("div#second > img").attr('src','22a.jpg');
}, function() {
$("div#first > img").attr('src','22a.jpg');
$("div#second > img").attr('src','22b.jpg');
});
Would something like this work for you?