iPhone Web App disable cache - javascript

I have built an iPhone webapp using PHP. The main (and only) page includes the apple-mobile-web-app-capable and apple-touch-fullscreen meta tags so that it can run fullscreen once added to the homescreen. However, it seems every time I launch the app from the homescreen, the cache version of the page is used instead of refreshing the page (and of course, I need the page to be updated on startup, and cannot use Ajax here - need to dynamically authenticate the user with SSO phpCAS). I did not use any manifest file and tried adding meta tags about cache without success. Does anybody know how to fix this?
Thanks

What meta tags have you tried?
<META HTTP-EQUIV="CACHE-CONTROL" CONTENT="NO-CACHE">
<META HTTP-EQUIV="PRAGMA" CONTENT="NO-CACHE">
should tell Safari not to cache, but I have not tried them.
You could use javascript to load your "real" startup page from the cached page using any of the standard techniques to make the URL unique, such as adding a random number.
That might even work for the main startup page, but I doubt it. Worth a try, though.
I suggest the cached page load a new page only if it is on the springboard:
UNTESTED suggestion:
window.onload = function () {
if (navigator.standalone) {
document.location.href = 'http://your.com/whatever.php?randomjunk=1234') }
}
so if the page is in the browser it can give instructions on saving to the home screen and if it is run from the home screen it will load the real page.

I know when you include a manifest file the main page is cached automatically, but I didn't think it happened when just using ...web-app-capable. Have you tried using a cache manifest file and listing your page under "Network:" to explicitly exclude it from this method of caching? If it isn't this it must be to do with the header and the meta information there.

Related

How do I ignore "Blocked loading mixed active content" [duplicate]

This morning, upon upgrading my Firefox browser to the latest version (from 22 to 23), some of the key aspects of my back office (website) stopped working.
Looking at the Firebug log, the following errors were being reported:
Blocked loading mixed active content "http://code.jquery.com/ui/1.8.10/themes/smoothness/jquery-ui.css"
Blocked loading mixed active content "http://ajax.aspnetcdn.com/ajax/jquery.ui/1.8.10/jquery-ui.min.js"`
among other errors caused by the latter of the two above not being loaded.
What does the above mean and how do I resolve it?
I found this blog post which cleared up a few things. To quote the most relevant bit:
Mixed Active Content is now blocked by default in Firefox 23!
What is Mixed Content?
When a user visits a page served over HTTP, their connection is open for eavesdropping and man-in-the-middle (MITM) attacks. When a user visits a page served over HTTPS, their connection with the web server is authenticated and encrypted with SSL and hence safeguarded from eavesdroppers and MITM attacks.
However, if an HTTPS page includes HTTP content, the HTTP portion can be read or modified by attackers, even though the main page is served over HTTPS. When an HTTPS page has HTTP content, we call that content “mixed”. The webpage that the user is visiting is only partially encrypted, since some of the content is retrieved unencrypted over HTTP. The Mixed Content Blocker blocks certain HTTP requests on HTTPS pages.
The resolution, in my case, was to simply ensure the jquery includes were as follows (note the removal of the protocol):
<link rel="stylesheet" href="//code.jquery.com/ui/1.8.10/themes/smoothness/jquery-ui.css" type="text/css">
<script type="text/javascript" src="//ajax.aspnetcdn.com/ajax/jquery.ui/1.8.10/jquery-ui.min.js"></script>
Note that the temporary 'fix' is to click on the 'shield' icon in the top-left corner of the address bar and select 'Disable Protection on This Page', although this is not recommended for obvious reasons.
UPDATE: This link from the Firefox (Mozilla) support pages is also useful in explaining what constitutes mixed content and, as given in the above paragraph, does actually provide details of how to display the page regardless:
Most websites will continue to work normally without any action on your part.
If you need to allow the mixed content to be displayed, you can do that easily:
Click the shield icon Mixed Content Shield in the address bar and choose Disable Protection on This Page from the dropdown menu.
The icon in the address bar will change to an orange warning triangle Warning Identity Icon to remind you that insecure content is being displayed.
To revert the previous action (re-block mixed content), just reload the page.
It means you're calling http from https. You can use src="//url.to/script.js" in your script tag and it will auto-detect.
Alternately you can use use https in your src even if you will be publishing it to a http page. This will avoid the potential issue mentioned in the comments.
In absence of a white-list feature you have to make the "all" or "nothing" Choice. You can disable mixed content blocking completely.
The Nothing Choice
You will need to permanently disable mixed content blocking for the current active profile.
In the "Awesome Bar," type "about:config". If this is your first time you will get the "This might void your warranty!" message.
Yes you will be careful. Yes you promise!
Find security.mixed_content.block_active_content. Set its value to false.
The All Choice
iDevelApp's answer is awesome.
Put the below <meta> tag into the <head> section of your document to force the browser to replace unsecure connections (http) to secured connections (https). This can solve the mixed content problem if the connection is able to use https.
<meta http-equiv="Content-Security-Policy" content="upgrade-insecure-requests">
If you want to block then add the below tag into the <head> tag:
<meta http-equiv="Content-Security-Policy" content="block-all-mixed-content">
Its given the error because of security.
for this please use "https" not "http" in the website url.
For example :
"https://code.jquery.com/ui/1.8.10/themes/smoothness/jquery-ui.css"
"https://ajax.aspnetcdn.com/ajax/jquery.ui/1.8.10/jquery-ui.min.js"
In the relevant page which makes a mixed content https to http call which is not accessible we can add the following entry in the relevant and get rid of the mixed content error.
<meta http-equiv="Content-Security-Policy" content="upgrade-insecure-requests">
If you are consuming an internal service via AJAX, make sure the url points to https, this cleared up the error for me.
Initial AJAX URL: "http://XXXXXX.com/Core.svc/" + ApiName
Corrected AJAX URL: "https://XXXXXX.com/Core.svc/" + ApiName,
Simply changing HTTP to HTTPS solved this issue for me.
WRONG :
<script src="http://code.jquery.com/jquery-3.5.1.js"></script>
CORRECT :
<script src="https://code.jquery.com/jquery-3.5.1.js"></script>
I had this same problem because I bought a CSS template and it grabbed a javascript an external javascript file through http://whatever.js.com/javascript.js. I went to that page in my browser and then changed it to https://whatever... using SSL and it worked, so in my HTML javascript tag I just changed the URL to use https instead of http and it worked.
To force redirect on https protocol, you can also add this directive in .htaccess on root folder
RewriteEngine on
RewriteCond %{REQUEST_SCHEME} =http
RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L]
#Blender Comment is the best approach. Never hard code the protocol anywhere in the code as it will be difficult to change if you move from http to https. Since you need to manually edit and update all the files.
This is always better as it automatically detect the protocol.
src="//code.jquery.com
I've managed to fix this using these :
For Firefox user
Open a new TAB enter about:config in the address bar to go to the configuration page.
Search for security.mixed_content.block_active_content
Change TRUE to FALSE.
For Chrome user
Click the Not Secure Warning next to the URL
Click Site Settings on the popup box
Change Insecure Content to Allow
Close and refresh the page
I found if you have issues with including or mixing your page with something like http://www.example.com, you can fix that by putting //www.example.com instead
I have facing same problem when my site goes from http to https. We have added rule for all request to redirect http to https.
You needs to add the redirection rule for inter site request, but you have to remove the redirection rule for external js/css.
I just fixed this problem by adding the following code in header:
<meta http-equiv="Content-Security-Policy" content="upgrade-insecure-requests">
#if (env('APP_DEBUG'))
<meta http-equiv="Content-Security-Policy" content="upgrade-insecure-requests">
#endif
Syntax for Laravel Blade, Remember to use it for debugging only to avoid MITM attacks and eavs-dropping
Also using
http -> https
for Ajax or normal JS Scripts or CSS will also solve the issue.
If your app server is weblogic, then make sure WLProxySSL ON entry exists(and also make sure it should not be commented) in the weblogic.conf file in webserver's conf directory. then restart web server, it will work.

How to hard reload/refresh a page using javascript

How do we do a hard reload/refresh in Chrome using Javascript?
window.location.reload(true);
location.reload(true);
didn't do it for me.
===========================
What I meant by 'didn't do it for me...'
The session cookies (ex. JSESSIONID) were not renewed specially the HttpOnly ones.
What I want to achieve...'
I wanted to reload the page like it's the first time I accessed the URL.
I wanted to simulate the steps below (which is like accessing the URL for the first time)
- Open browser
- Type URL
- Hit Enter
I wonder if there is a more powerful Javascript command that reloads as if it is the first time.
The best (and practically only) way to ensure a page is hard reloaded is by using your server. One of the ways you can do this is by serving headers, when a page is requested, that invalidate resources such as Cache-Control which will tell the browser to not cache resources and always revalidate resources which means everything must be redownloaded each time.
I would not recommend serving this header on every request in your production application, though.
Cache-Control: no-store, max-age=0
On your page you can add meta tags that will tell the browser what to do, provided there weren't headers already passed to the browser. This depends on how you serve your content, but you can add the following to your head element which will tell the browser to store absolutely nothing and is equivalent to hitting a page for the first time:
<head>
...
<meta http-equiv="Cache-Control" content="no-store, max-age=0">
...
</head>
location.reload() should work. Works for me!

How to circumvent browser caching? [duplicate]

Is there a way I can put some code on my page so when someone visits a site, it clears the browser cache, so they can view the changes?
Languages used: ASP.NET, VB.NET, and of course HTML, CSS, and jQuery.
If this is about .css and .js changes, then one way is "cache busting" by appending something like "_versionNo" to the file name for each release. For example:
script_1.0.css // This is the URL for release 1.0
script_1.1.css // This is the URL for release 1.1
script_1.2.css // etc.
or after the file name:
script.css?v=1.0 // This is the URL for release 1.0
script.css?v=1.1 // This is the URL for release 1.1
script.css?v=1.2 // etc.
You can check this link to see how it could work.
Look into the cache-control and the expires META Tag.
<META HTTP-EQUIV="CACHE-CONTROL" CONTENT="NO-CACHE">
<META HTTP-EQUIV="EXPIRES" CONTENT="Mon, 22 Jul 2002 11:12:01 GMT">
Another common practices is to append constantly-changing strings to the end of the requested files. For instance:
<script type="text/javascript" src="main.js?v=12392823"></script>
Update 2012
This is an old question but I think it needs a more up to date answer because now there is a way to have more control of website caching.
In Offline Web Applications (which is really any HTML5 website) applicationCache.swapCache() can be used to update the cached version of your website without the need for manually reloading the page.
This is a code example from the Beginner's Guide to Using the Application Cache on HTML5 Rocks explaining how to update users to the newest version of your site:
// Check if a new cache is available on page load.
window.addEventListener('load', function(e) {
window.applicationCache.addEventListener('updateready', function(e) {
if (window.applicationCache.status == window.applicationCache.UPDATEREADY) {
// Browser downloaded a new app cache.
// Swap it in and reload the page to get the new hotness.
window.applicationCache.swapCache();
if (confirm('A new version of this site is available. Load it?')) {
window.location.reload();
}
} else {
// Manifest didn't changed. Nothing new to server.
}
}, false);
}, false);
See also Using the application cache on Mozilla Developer Network for more info.
Update 2016
Things change quickly on the Web.
This question was asked in 2009 and in 2012 I posted an update about a new way to handle the problem described in the question. Another 4 years passed and now it seems that it is already deprecated. Thanks to cgaldiolo for pointing it out in the comments.
Currently, as of July 2016, the HTML Standard, Section 7.9, Offline Web applications includes a deprecation warning:
This feature is in the process of being removed from the Web platform.
(This is a long process that takes many years.) Using any of the
offline Web application features at this time is highly discouraged.
Use service workers instead.
So does Using the application cache on Mozilla Developer Network that I referenced in 2012:
Deprecated This feature has been removed from the Web standards.
Though some browsers may still support it, it is in the process of
being dropped. Do not use it in old or new projects. Pages or Web apps
using it may break at any time.
See also Bug 1204581 - Add a deprecation notice for AppCache if service worker fetch interception is enabled.
Not as such. One method is to send the appropriate headers when delivering content to force the browser to reload:
Making sure a web page is not cached, across all browsers.
If your search for "cache header" or something similar here on SO, you'll find ASP.NET specific examples.
Another, less clean but sometimes only way if you can't control the headers on server side, is adding a random GET parameter to the resource that is being called:
myimage.gif?random=1923849839
I had similiar problem and this is how I solved it:
In index.html file I've added manifest:
<html manifest="cache.manifest">
In <head> section included script updating the cache:
<script type="text/javascript" src="update_cache.js"></script>
In <body> section I've inserted onload function:
<body onload="checkForUpdate()">
In cache.manifest I've put all files I want to cache. It is important now that it works in my case (Apache) just by updating each time the "version" comment. It is also an option to name files with "?ver=001" or something at the end of name but it's not needed. Changing just # version 1.01 triggers cache update event.
CACHE MANIFEST
# version 1.01
style.css
imgs/logo.png
#all other files
It's important to include 1., 2. and 3. points only in index.html. Otherwise
GET http://foo.bar/resource.ext net::ERR_FAILED
occurs because every "child" file tries to cache the page while the page is already cached.
In update_cache.js file I've put this code:
function checkForUpdate()
{
if (window.applicationCache != undefined && window.applicationCache != null)
{
window.applicationCache.addEventListener('updateready', updateApplication);
}
}
function updateApplication(event)
{
if (window.applicationCache.status != 4) return;
window.applicationCache.removeEventListener('updateready', updateApplication);
window.applicationCache.swapCache();
window.location.reload();
}
Now you just change files and in manifest you have to update version comment. Now visiting index.html page will update the cache.
The parts of solution aren't mine but I've found them through internet and put together so that it works.
For static resources right caching would be to use query parameters with value of each deployment or file version. This will have effect of clearing cache after each deployment.
/Content/css/Site.css?version={FileVersionNumber}
Here is ASP.NET MVC example.
<link href="#Url.Content("~/Content/Css/Reset.css")?version=#this.GetType().Assembly.GetName().Version" rel="stylesheet" type="text/css" />
Don't forget to update assembly version.
I had a case where I would take photos of clients online and would need to update the div if a photo is changed. Browser was still showing the old photo. So I used the hack of calling a random GET variable, which would be unique every time. Here it is if it could help anybody
<img src="/photos/userid_73.jpg?random=<?php echo rand() ?>" ...
EDIT
As pointed out by others, following is much more efficient solution since it will reload images only when they are changed, identifying this change by the file size:
<img src="/photos/userid_73.jpg?modified=<? filemtime("/photos/userid_73.jpg")?>"
A lot of answers are missing the point - most developers are well aware that turning off the cache is inefficient. However, there are many common circumstances where efficiency is unimportant and default cache behavior is badly broken.
These include nested, iterative script testing (the big one!) and broken third party software workarounds. None of the solutions given here are adequate to address such common scenarios. Most web browsers are far too aggressive caching and provide no sensible means to avoid these problems.
Updating the URL to the following works for me:
/custom.js?id=1
By adding a unique number after ?id= and incrementing it for new changes, users do not have to press CTRL + F5 to refresh the cache. Alternatively, you can append hash or string version of the current time or Epoch after ?id=
Something like ?id=1520606295
<meta http-equiv="pragma" content="no-cache" />
Also see https://stackoverflow.com/questions/126772/how-to-force-a-web-browser-not-to-cache-images
Here is the MDSN page on setting caching in ASP.NET.
Response.Cache.SetExpires(DateTime.Now.AddSeconds(60))
Response.Cache.SetCacheability(HttpCacheability.Public)
Response.Cache.SetValidUntilExpires(False)
Response.Cache.VaryByParams("Category") = True
If Response.Cache.VaryByParams("Category") Then
'...
End If
Not sure if that might really help you but that's how caching should work on any browser. When the browser request a file, it should always send a request to the server unless there is a "offline" mode. The server will read some parameters like date modified or etags.
The server will return a 304 error response for NOT MODIFIED and the browser will have to use its cache. If the etag doesn't validate on server side or the modified date is below the current modified date, the server should return the new content with the new modified date or etags or both.
If there is no caching data sent to the browser, I guess the behavior is undetermined, the browser may or may not cache file that don't tell how they are cached. If you set caching parameters in the response it will cache your files correctly and the server then may choose to return a 304 error, or the new content.
This is how it should be done. Using random params or version number in urls is more like a hack than anything.
http://www.checkupdown.com/status/E304.html
http://en.wikipedia.org/wiki/HTTP_ETag
http://www.xpertdeveloper.com/2011/03/last-modified-header-vs-expire-header-vs-etag/
After reading I saw that there is also a expire date. If you have problem, it might be that you have a expire date set up. In other words, when the browser will cache your file, since it has a expiry date, it shouldn't have to request it again before that date. In other words, it will never ask the file to the server and will never receive a 304 not modified. It will simply use the cache until the expiry date is reached or cache is cleared.
So that is my guess, you have some sort of expiry date and you should use last-modified etags or a mix of it all and make sure that there is no expire date.
If people tends to refresh a lot and the file doesn't get changed a lot, then it might be wise to set a big expiry date.
My 2 cents!
I implemented this simple solution that works for me (not yet on production environment):
function verificarNovaVersio() {
var sVersio = localStorage['gcf_versio'+ location.pathname] || 'v00.0.0000';
$.ajax({
url: "./versio.txt"
, dataType: 'text'
, cache: false
, contentType: false
, processData: false
, type: 'post'
}).done(function(sVersioFitxer) {
console.log('Versió App: '+ sVersioFitxer +', Versió Caché: '+ sVersio);
if (sVersio < (sVersioFitxer || 'v00.0.0000')) {
localStorage['gcf_versio'+ location.pathname] = sVersioFitxer;
location.reload(true);
}
});
}
I've a little file located where the html are:
"versio.txt":
v00.5.0014
This function is called in all of my pages, so when loading it checks if the localStorage's version value is lower than the current version and does a
location.reload(true);
...to force reload from server instead from cache.
(obviously, instead of localStorage you can use cookies or other persistent client storage)
I opted for this solution for its simplicity, because only mantaining a single file "versio.txt" will force the full site to reload.
The queryString method is hard to implement and is also cached (if you change from v1.1 to a previous version will load from cache, then it means that the cache is not flushed, keeping all previous versions at cache).
I'm a little newbie and I'd apreciate your professional check & review to ensure my method is a good approach.
Hope it helps.
In addition to setting Cache-control: no-cache, you should also set the Expires header to -1 if you would like the local copy to be refreshed each time (some versions of IE seem to require this).
See HTTP Cache - check with the server, always sending If-Modified-Since
There is one trick that can be used.The trick is to append a parameter/string to the file name in the script tag and change it when you file changes.
<script src="myfile.js?version=1.0.0"></script>
The browser interprets the whole string as the file path even though what comes after the "?" are parameters. So wat happens now is that next time when you update your file just change the number in the script tag on your website (Example <script src="myfile.js?version=1.0.1"></script>) and each users browser will see the file has changed and grab a new copy.
Force browsers to clear cache or reload correct data? I have tried most of the solutions described in stackoverflow, some work, but after a little while, it does cache eventually and display the previous loaded script or file. Is there another way that would clear the cache (css, js, etc) and actually work on all browsers?
I found so far that specific resources can be reloaded individually if you change the date and time on your files on the server. "Clearing cache" is not as easy as it should be. Instead of clearing cache on my browsers, I realized that "touching" the server files cached will actually change the date and time of the source file cached on the server (Tested on Edge, Chrome and Firefox) and most browsers will automatically download the most current fresh copy of whats on your server (code, graphics any multimedia too). I suggest you just copy the most current scripts on the server and "do the touch thing" solution before your program runs, so it will change the date of all your problem files to a most current date and time, then it downloads a fresh copy to your browser:
<?php
touch('/www/sample/file1.css');
touch('/www/sample/file2.js');
?>
then ... the rest of your program...
It took me some time to resolve this issue (as many browsers act differently to different commands, but they all check time of files and compare to your downloaded copy in your browser, if different date and time, will do the refresh), If you can't go the supposed right way, there is always another usable and better solution to it. Best Regards and happy camping. By the way touch(); or alternatives work in many programming languages inclusive in javascript bash sh php and you can include or call them in html.
For webpack users:-
I added time with chunkhash in my webpack config. This solved my problem of invalidating cache on each deployment. Also we need to take care that index.html/ asset.manifest is not cached both in your CDN or browser. Config of chunk name in webpack config will look like this:-
fileName: [chunkhash]-${Date.now()}.js
or If you are using contenthash then
fileName: [contenthash]-${Date.now()}.js
This is the simple solution I used to solve in one of my applications using PHP.
All JS and CSS files are placed in a folder with version name. Example : "1.0.01"
root\1.0.01\JS
root\1.0.01\CSS
Created a Helper and Defined the version Number there
<?php
function system_version()
{
return '1.0.07';
}
And Linked JS and SCC Files like below
<script src="<?= base_url(); ?>/<?= system_version();?>/js/generators.js" type="text/javascript"></script>
<link rel="stylesheet" type="text/css" href="<?= base_url(); ?>/<?= system_version(); ?>/css/view-checklist.css" />
Whenever I make changes to any JS or CSS file, I change the System Verson in Helper and rename the folder and deploy it.
I had the same problem, all i did was change the file names which are linked to my index.html file and then went into the index.html file and updated their names, not the best practice but if it works it works. The browser sees them as new files so they get redownloaded on to the users device.
example:
I want to update a css file, its named styles.css, change it to styless.css
Go into index.html and update , and change it to
in case interested I've found my solution to get browsers refreshing .css and .js in the context of .NET MVC (.net fw 4.8) and the use of bundles.
I wanted to make browsers refresh cached files only after a new assembly is deployed.
Buinding on Paulius Zaliaduonis response, my solution is as follows:
store your application base url in the web config app settings (the HttpContext is not yet available at runtime during the RegisterBundle...), then make this parameter changing according to the configuration (debug, staging, release...) by the xml transform
In BundleConfig RegisterBundles get the assembly version by the means of reflection, and...
...change the default tag format of both styles and scripts so that the bundling system generates link and script tags appending a query string parameter on them.
Here is the code
public static void RegisterBundles(BundleCollection bundles)
{
string baseUrl = system.Configuration.ConfigurationManager.AppSettings["by.app.base.url"].ToString();
string assemblyVersion = Assembly.GetExecutingAssembly().GetName().Version.ToString();
Styles.DefaultTagFormat = $"<link href='{baseUrl}{{0}}?v={assemblyVersion}' rel='stylesheet'/>";
Scripts.DefaultTagFormat = $"<script src='{baseUrl}{{0}}?v={assemblyVersion}'></script>";
}
You'll get tags like
<script src="https://example.org/myscriptfilepath/script.js?v={myassemblyversion}"></script>
you just need to remember to to build a new version before deploying.
Ciao
Do you want to clear the cache, or just make sure your current (changed?) page is not cached?
If the latter, it should be as simple as
<META HTTP-EQUIV="Pragma" CONTENT="no-cache">

Force JavaScript update for Friconix

I embeded Friconix on my web site (a free icon collection like Font Awesome).
I noticed that when new icons are added in the library, they are not available since the JavaScript file is refreshed in cache.
Is there a way to force the client to refresh JavaScript ?
You can't force browsers to clear their cache. But you can change the path to your script. For example, add a GET parameter with version to the path, like this:
<script src="/js/main.js?ver=2"></script>
location.reload has a parameter of type Boolean that specifies a hard reload. (This isn't too reliable - it depends on the browser and safety/security measures in place):
location.reload(true);
Alternatively, use a no-cache meta tag:
<meta http-equiv="Cache-control" content="no-cache" />

Trigger prefetching after page is fully loaded

My scenario is:
user visits domain.com (home page)
domain.com/products page contains large image library and quite large CSS and JS libraries
when user visits domain.com and the home page has fully loaded, we start to prefetch resources & if possible at least some % of images from the archive.
Currently on some pages JS "eats" quite a lot of resources therefor triggering prefetch in some cases during page load is not the best answer - as it will cause a small lag when user interacts with JS created events and elements.
My questions are:
Is it even possible (will it work) to trigger <link rel="prefetch" href="image.png"> or CSS file to be added to <head> so it can prefetch data from another page after current page is fully loaded?
Should I do it similar like rendering additional stylesheet using JS where I add new tag within <head> as a stylesheet file so it can then render.. or is there another way?
You might use Cache Storage to prefetch (precache) assets. I work on an open-source project which uses this approach. Although, to serve precached assets you need a service worker. The logic of finding assets in my project looks like this.
The demo of this project is here. Also, I wrote an article which explains technical details of the project.
Assets get prefetched once the lib is loaded, so I don't wait for the entire page load. Maybe I should use requestIdleCallback to wait until the browser is idle.
Hopefully, it gives you some inspiration.
Just to note that you could add aditional stylesheet after the page load completly or whenever you want with somethig like this:
document.addEventListener("DOMContentLoaded", function(event) {
var script = document.createElement("link");
script.rel = "stylesheet";
script.href= "stylesOfAnotherPage2.css";
document.getElementsByTagName("body")[0].appendChild(script);//or head
});
When you load page1, stylesOfAnotherPage2.css is cached, so when page2 is called, stylesOfAnotherPage2.css is already cached if page2 call the same file.
You might use HTTP Caching and Link prefetching to use your browser idle time to download or prefetch documents that the user might visit in the near future.
Prefetching hints
The browser observes all of these hints and queues up each unique
request to be prefetched when the browser is idle. There can be
multiple hints per page, as it might make sense to prefetch multiple
documents. For example, the next document might contain several large
images.
<link rel="prefetch alternate stylesheet" title="Designed for Mozilla" href="mozspecific.css">
<link rel="next" href="2.html">
Also, you can read this thread:
Preload, Prefetch And Priorities in Chrome
There you can read the different states and priorities about the execution, load and preload times, some tips to improve them.
preload of CSS and JS using https://developer.mozilla.org/en-US/docs/Web/HTML/Preloading_content might be a good fit and has good support in most modern browsers: https://caniuse.com/#search=preload
There are probably better solutions, such as the one suggested by #soulshined, but another crude way to do this is the other page contains etags or cache control headers would be to use AJAX to send requests to the resources you expect to load. This would cause the browser to request those resources and prefill the user agent cache so that when the user requests that resource on the other page there is a higher change the cache would contain the resources and it'd load faster than if it had to fetch everything for the first time.
To prefetch assets there are some prefetching methods such as DNS-prefetch, pre-connect, pre-render & prefetch. As per the requirement, you may use them appropriately. Each method has its own purpose this would be useful to know each one specifically.

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