Refresh iFrame (Cache Issue)
We are getting a weird issue on which we are not sure what exactly cause it. Let me elaborate the issue. Suppose, we have two different html pages a.html and b.html. And a little script written in index.html:
<html>
<head>
<script>
function reloadFrame(iframe, src) {
iframe.src = src;
}
</script>
</head>
<body>
<form>
<iframe id="myFrame"></iframe>
<input type="button" value="Load a.html" onclick="reloadFrame(document.getElementById('myFrame'), 'a.html')">
<input type="button" value="Load b.html" onclick="reloadFrame(do开发者_运维百科cument.getElementById('myFrame'), 'b.html')">
</form>
</body>
</html>
A server component is continuously updating both files a.html and b.html. The problem is the content of both files are successfully updating on the server side. If we open we can see the updated changes but client getting the older content which doesn't show the updated changes.
Any idea?
Add this in a.html and b.html
<head>
<meta http-Equiv="Cache-Control" Content="no-cache" />
<meta http-Equiv="Pragma" Content="no-cache" />
<meta http-Equiv="Expires" Content="0" />
</head>
To force no cache checks
If you can add server-side instructions to those HTML files, you could send the appropriate headers to prevent caching:
Making sure a web page is not cached, across all browsers (I think the consensus is that the 2nd answer is best, not the accepted one)
Simone's answer already deals with Meta tags.
A cheap quick trick is to add a random number as a GET parameter:
page_1.html?time=102398405820
if this changes on every request (e.g. using the current time), reloading wil get forced every time, too.
Try something like the following:
<script>
var frameElement = document.getElementById("frame-id");
frameElement.contentWindow.location.href = frameElement.src;
</script>
This will force the iframe to be reloaded even if it was cached by the browser
I want to put Vishwas comment as a separate answer, extending Pekka’s answer
//ensure iframe is not cached
function reloadIframe(iframeId) {
var iframe = document.getElementById(iframeId);
var d = new Date();
if (iframe) {
iframe.src = iframe.src + '?ver=' + d.getTime();
//alternatively frameElement.contentWindow.location.href = frameElement.src; //This will force the iframe to be reloaded even if it was cached by the browser
}
}
reloadIframe('session_storage_check');
Homero Barbosa's Solution worked like a charm. In my case, I had a varying number of iframes on the page, so I did the following:
$('.some_selector').each(function () {
var $randid = Math.floor(Math.random() * 101);
$(this).attr({'id': 'goinOnaSafari-' + $randid});
var $frame = document.getElementById('goinOnaSafari-' + $randid);
$frame.contentWindow.location.href = $frame.src;
});
I could not get the HTML to work.
<head>
<meta http-Equiv="Cache-Control" Content="no-cache" />
<meta http-Equiv="Pragma" Content="no-cache" />
<meta http-Equiv="Expires" Content="0" />
</head>
For development in chrome I checked the console Network tab and found where the iframe is loaded. I confirmed that it was loaded with a 304 response wich means it loads from cache. Right click -> clear browser cache.
Will not work in production, but at least helps with development.
For one possible solution to this, pass a "cache parameter" to your calls to a.html and b.html. For example
HTML
<input type="button" value="Load a.html" onclick="cacheSafeReload('a.html');">
Javascript
function cacheSafeReload(urlBase) {
var cacheParamValue = (new Date()).getTime();
var url = urlBase + "?cache=" + cacheParamValue;
reloadFrame(document.getElementById('myFrame'), url);
}
加载中,请稍侯......
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