I am trying to use javascript, html, css to create a page that I can resize an image from an online link. However, when resized, I faced the error that Tainted canvases may not be exported while using Canvas.toDataURL()
. I have searched the issue in google and here. Somebody suggested to amend the photo's crossorigin to anonymous or '*'. I tried both methods but it doesn't work for me. I wonder anyone can offer help. My code is in the below link.
https://jsfiddle.net/pangkachun/7axkq9pe/1/
var min_img_width = 60;
var min_img_height = 60;
var max_img_width = 1000;
var max_img_height = 1000;
var resizeableImage = function(image_target) {
// Some variable and settings
var $container,
orig_src = new Image(),
image_target = $(image_target).get(0),
event_state = {},
constrain = false,
min_width = min_img_width, // Change as required
min_height = min_img_height,
max_width = max_img_width, // Change as required
max_height = max_img_height,
resize_canvas = document.createElement('canvas'),
// ----------------- function to int the page ----------------------//
init = function(){
// When resizing, we will always use this copy of the original as the base
orig_src.src = image_target.src;
orig_src.crossorigin = 'anonymous';
// Wrap the image with the container and add resize handles
$(image_target).wrap('<div class="resize-container"></div>')
.before('<span class="resize-handle resize-handle-nw"></span>')
.before('<span class="resize-handle resize-handle-ne"></span>')
.after('<span class="resize-handle resize-handle-se"></span>')
.after('<span class="resize-handle resize-handle-sw"></span>');
// Assign the container to a variable
$container = $(image_target).parent('.resize-container');
// Add events (one for resize (resize handle) and one for moving - img)
// addEventListenor -> mouse touchdown, resize handle, resize_img
$container.on('mousedown touchstart', '.resize-handle', startResize);
};
// ------------------ end function to int the page -------------------------//
// to save the data upon a event is fired
saveEventState = function(e){
// Save the initial event details and container state
event_state.container_width = $container.width();
event_state.container_height = $container.height();
event_state.container_left = $container.offset().left;
event_state.container_top = $container.offset().top;
event_state.mouse_x = (e.clientX || e.pageX || e.originalEvent.touches[0].clientX) + $(window).scrollLeft();
event_state.mouse_y = (e.clientY || e.pageY || e.originalEvent.touches[0].clientY) + $(window).scrollTop();
// This is a fix for mobile safari
// For some reason it does not allow a direct copy of the touches property
if(typeof e.originalEvent.touches !== 'undefined'){
event_state.touches = [];
$.each(e.originalEvent.touches, function(i, ob){
event_state.touches[i] = {};
event_state.touches[i].clientX = 0+ob.clientX;
event_state.touches[i].clientY = 0+ob.clientY;
});
}
event_state.evnt = e;
};
// function to redraw the image based on width and height
redrawImage = function(width, height){
resize_canvas.width = width;
resize_canvas.height = height;
resize_canvas.getContext('2d').drawImage(orig_src, 0, 0, width, height);
$(image_target).attr('src', resize_canvas.toDataURL("image/png"));
};
//------------------------ resizing function starts ----------------------------//
startResize = function(e){
e.preventDefault();
e.stopPropagation();
saveEventState(e);
$(document).on('mousemove touchmove', resizing);
$(document).on('mouseup touchend', endResize);
};
endResize = function(e){
e.preventDefault();
$(document).off('mouseup touchend', endResize);
$(document).off('mousemove touchmove', resizing);
};
resizing = function(e){
var mouse = {}, width, height, left, top, offset=$container.offset();
mouse.x = (e.clientX || e.pageX || e.originalEvent.touches[0].clientX) + $(window).scrollLeft();
mouse.y = (e.clientY || e.pageY || e.originalEvent.touches[0].clientY) + $(window).scrollTop();
// Position image differently depending on the corner dragged and constraints
if( $(event_state.evnt.target).hasClass('resize-handle-se') ){
width = mouse.x - event_state.container_left;
height = mouse.y - event_state.container_top;
left = event_state.container_left;
top = event_state.container_top;
} else if($(event_state.evnt.target).hasClass('resize-handle-sw') ){
width = event_state.container_width - (mouse.x - event_state.container_left);
height = mouse.y - event_state.container_top;
left = mouse.x;
top = event_state.container_top;
} else if($(event_state.evnt.target).hasClass('resize-handle-nw') ){
width = event_state.container_width - (mouse.x - event_state.container_left);
height = event_state.container_height - (mouse.y - event_state.container_top);
left = mouse.x;
top = mouse.y;
if(constrain || e.shiftKey){
top = mouse.y - ((width / orig_src.width * orig_src.height) - height);
}
} else if($(event_state.evnt.target).hasClass('resize-handle-ne') ){
width = mouse.x - event_state.container_left;
height = event_state.container_height - (mouse.y - event_state.container_top);
left = event_state.container_left;
top = mouse.y;
}
if(width > min_width && height > min_height && width < max_width && height < max_height){
// To improve performance you might limit how often resizeImage() is called
redrawImage(width, height);
// Without this Firefox will not re-calculate the the image dimensions until drag end
$container.offset({'left': left, 'top': top});
}
}
//------------------------ resizing functino end ----------------------------//
init();
};
resizeableImage($('.resize-image'));
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script><!DOCTYPE html><html lang="en" class="no-js"><head><title>Image Resizing with Canvas</title><link rel="stylesheet" type="text/css" href="css/component.css" /><!--[if IE]><script src="http://html5shiv.googlecode.com/svn/trunk/html5.js"></script><![endif]--></head><body><div class="container"><div class="content"><header class="codrops-header"><h1>Image Resizing & Cropping <br /><span>with Canvas</span></h1></header><div class="component"><div class="overlay"><div class="overlay-inner"></div></div><img class="resize-image" id='test-img'crossorigin="anonymous" src="https://static-cdn.pixlr.com/images/image-design.png" alt="image for resizing"></div></div><!-- /content --></div> <!-- /container --><script src="js/jquery-2.1.1.min.js"></script><script src="js/component.js"></script></body></html>
Thanks a lot.