1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
|
{{*
Force the browser to reload an image from the server instead of the cache.
based on an answer from http://stackoverflow.com/a/22429796/3343347
Usage: Set $imgUrl to the src url you want to be re-fetched from the server
*}}
<script>
$(document).ready(
function() {
forceImgReload("{{$imgUrl}}");
}
);
{{*
* find and return any existing img tags with a matching src url, and set them to an intermediate
* src url so they can later be reverted back once the cached version has been updated.
*}}
function prepareImagesForReload(srcUrl) {
var result = $("img[src='" + srcUrl + "']").get();
for (i = 0; i < result.length; i++) {
{{*
* Set the image to a reloading image, in this case an animated "reloading" svg
* Ideally this wont be displayed long enough to matter.
*}}
result[i].src = "data:image/svg+xml;charset=utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 100 100' preserveAspectRatio='xMidYMid' class='uil-reload'%3E%3Cpath fill='none' class='bk' d='M0 0h100v100H0z'/%3E%3Cg%3E%3Cpath d='M50 15a35 35 0 1 0 24.787 10.213' fill='none' stroke='%23777' stroke-width='12'/%3E%3Cpath d='M50 0v30l16-15L50 0' fill='%23777'/%3E%3CanimateTransform attributeName='transform' type='rotate' from='0 50 50' to='360 50 50' dur='1s' repeatCount='indefinite'/%3E%3C/g%3E%3C/svg%3E";
}
return result;
}
function restoreImages(srcUrl, imgList) {
for (i = 0; i < imgList.length; i++) {
imgList[i].src = srcUrl;
}
}
function forceImgReload(srcUrl) {
var imgList;
var step = 0;
var iframe = window.document.createElement("iframe"); // Hidden iframe, in which to perform the load+reload.
{{* Callback function, called after iframe load+reload completes (or fails).
Will be called TWICE unless twostage-mode process is cancelled. (Once after load, once after reload). *}}
var iframeLoadCallback = function(e) {
if (step === 0) {
// initial load just completed. Note that it doesn't actually matter if this load succeeded or not.
step = 1;
imgList = prepareImagesForReload(srcUrl);
iframe.contentWindow.location.reload(true); // initiate forced-reload!
} else if (step === 1) {
// forced re-load is done
restoreImages(srcUrl, imgList);
if (iframe.parentNode) iframe.parentNode.removeChild(iframe);
}
}
iframe.style.display = "none";
window.parent.document.body.appendChild(iframe); {{* NOTE: if this is done AFTER setting src, Firefox MAY fail to fire the load event! *}}
iframe.addEventListener("load", iframeLoadCallback, false);
iframe.addEventListener("error", iframeLoadCallback, false);
iframe.src = srcUrl;
}
</script>
|
