I have a react app which works perfectly fine.
However we are pushing code after NPM BUILD and deploying the code manually via SFTP
We can see the JS and CSS files have different names.
However the browser keeps downloading css and js files form cache, even if I disable cache in the browser.
I tried deleting all files in FTP, and magically the website keeps working? so it looks all the files are retrieved from the browser cache even if nothing exists in the server
I tried stopping and starting the azure website, but didnt make any difference
I tried cleaning the browser, cache, history, etc, no difference.
I wonder if I need to setup something in web.config, or in Azure website settings to make this works
This seems to be not an issue with Azure app service (Web app), you need to remove the caching of the react app with the following steps
Step 1: adding the following to in index.html
<meta http-equiv="Pragma" content="no-cache" />
<meta http-equiv="Expires" content="0" />
Step 2: inserting the following to the js
import { unregister } from './registerServiceWorker';
and call
unregister()
Reference Answer
It depends on how your app is configured, but I would not recommend disabling cache on the JS & CSS. Instead, it's best to add some version-dependent information to the file name so every time the JS or CSS update the file name changes.
Last time I worked on a web project we had it such that our JS & CSS had a content hash at the end. Something along the lines of main.205199ab45963f6a62ec.js instead of just main.js. Also note that you don't even have to manage that hash yourself, as there are ways to get ASP.NET or webpack (etc...) to update the reference in the HTML/JSX for you.
Here's webpack's page about it: https://webpack.js.org/guides/caching/
Related
I'm using Nextjs for a front-end application and dotnet core 3.1 for the Web API. There are some pages that are static and other that are dynamic I followed the official documentation to achieve this. On development mode (local machine) everything works fine. Both static and dynamic routes are working properly and fetching data from the dontnet core Web API.
However, when publishing the Nextjs app following this steps:
yarn build
yarn export
An out folder is generated at the root of the project
The content of that folder is uploaded to the server
After, the deployed files are uploaded and when loging to the app, it redirects to the main page (until here is working OK), but as soon as I click on the reload page botton (Chrome) I am gettint the 404 error.
Looking at the console in the developer tools I got this:
I found this Stackoverflow link with same issue but there the answer is to use Express for server routing. In my case I am using dotnet core Web API for server requests. So, not sure how to do that.
Is there a way to fix this from the client side? Might be a configuration is missing?
The only thing I noticed while doing the export was a message saying: No "exportPathMap" found. Not sure if that would the the reason.
I had got similar issue in react when all of my pages after building and exporting had ".html" extensions. I solved it by the following code in next.config.js file.
next.config.js
module.exports = {
exportTrailingSlash: true,
}
Note: Do not work with the above code while in development. Use it just before building the project.
You can find the documentation link here: https://nextjs.org/docs/api-reference/next.config.js/exportPathMap#adding-a-trailing-slash.
UPDATE
The above code was for next.js v9.3.4 which I was using at that time. For newer versions below code should be used according to docs.
next.config.js
module.exports = {
trailingSlash: true,
}
it has been fixed update your nextjs package
npm install next#latest
based on the current version of Next js you have, visit here to see if there's any breaking change before updating what you have
I had a similar issue where after deploying the out folder created by next export all URL's would redirect me to the homepage. Everything was working fine during development and all URL's were accessible with next/link but in order to access pages with a URL I had to add a .html extension at the end of the URL.
Because I needed a quick workaround I added a useEffect block in the _app.tsx file for rerouting so that upon landing on the homepage it would act as if a Link component was clicked redirecting to the entered URL.
useEffect(()=>{
router.push(window.location.href)
},[])
How is routing handled in a built react app?
Specifically, in a development environment, we can simply hit <host>:<port>/<some-path> and the corresponding component is loaded, but once the app is built, we get a bunch of static files and single index.html file, which are then served by some server.
Now, upon hitting the url <server-host>:<server-port>, the app works as intended, but upon entering the path, say <server-host>:<server-port>/<component-path>, a 404 error is returned.
If there is, say a button, upon clicking which, the same /<component-path> is to be redirected, the app works, but then again upon refreshing that page, 404 error occurs.
How can this be solved? What is the correct way to serve such apps having many components at different routes?
approach1:(recommended)
In server config you should point all urls ( http://ipaddress:port/<* any url pattern>) to index.html of react-app . this is known as fallback-mechanism.
And when any request comes,index.html of React app will take care of that automatically because it is single page application.
approach2:
Use HashRouter in React app. So You will not have to configure anything.
Depending on which server you are deploying to, you should redirect all errors to the index.html look for the configuration maybe htaccess or for example if it an AWS S3 bucket you just specify the error page to the same index.html file that is served. Then you handle actual error in your code using a routing library like maybe react-router-dom to take care of actual error. Your failure is because in normal circumstances in a static host when you provide a URL like <server-port>/<component-path> the assumption the server makes is that there is a folder with name component-path in your root directory which has an index file from where to load and display but in the case of React single page application, everything is managed by the index.html. So every request has to pass via the index.html
I have a react application build with create-react-app. Its using octoberCMS as the backend fetching data using Axios calls from the frontend. Till now I was developing keeping the build content of react inside a directory named 'react' in the root directory of octoberCMS installation. Hence the URL I was hitting was http://example.com/react/.
The problem is now I am done with the development phase and look forward to deployment. But I want my front-end to be served at http://example.com and backend to be served at http://example.com/backend (backend served as I want). How can I achieve this? I am fairly new to both frameworks.
I have tried keeping the build content along with the rest of the octoberCMS
First build your react app that will give you vendor.js[third party scripts] and your app.js[your actual app]
put them in to theme directory assets something
Then In Ocotber CMS make page with URL /:url? and paste your index.html content there.
it will be your root div and including js html, change path for js which points to the build js which you put in theme directory.
now what happens when anybody come to site
- we are serving same content as we do in dev build
- index.html with root tag and needed js
Now if use hit any other url like https://www.example.com/test/etc it also will be catch by /:url? (and all other requests) and home page served and our react app will work as we needed.
if any questions please comment.
I have a React application created by create-react-app. The app works fine, but I have run into a problem
I need to test som ad things on a plain html site, no additional React code. The problem I have is that the ads.txt tags need to be crawled by Google, which can take up to 24 hours on a new page/URL, time that I don't really have.
So I did the following. In my repo under /public folder I added a folder /ad-test with an index.html inside. When I serve it locally using npm start and go to http://localhost:3000/ad-test, it works fine.
Great, I thought and deployed it to the production environment, but now when I try to go to http://[my-site]/ad-test or http://[my-site]/yo-test/index.html it does not work (I get the React 404 site that I created).
I looked here and if I understand correctly, it is not possible to do it the way that I tried since the build stage will not include the public folder. Am I correct in this?
Any idea how to solve this?
EDIT:
I have a good knowledge of React and React Router in general, the app already uses <Switch><Route ... /></Switch> with a catch-all route directing to Not Found Component and the bottom.
The problem I have is that we include some ad scripts from an ad provider. The ads are not displayed in the application (adblockers totally removed from browser etc.) and the provider thinks that we have made errors in the React code.
We don't think that we made any errors (the ads were displayed fine in our test environment but not in prod) and we have to prove that React is not to blame for the ads not showing.
To do this we created a static HTML file with all ads hardcoded, no React components or other things that might disturb. BUT, because of ads and Google crawlers and ads.txt, we need to have the static test page under the same domain as our main page/application.
This is why I ask if it is possible to somehow add a static HTML that can be reached from http://my.page/test-page.html without being "intercepted" by react router, i.e. it exists outside React but on the same server.
When you use react by create-react-app, it means you are building a single-page application.
What this means is that after running npm run build you will have a build folder with only one html file called index.html in that fold.
This index.html does not know and has no relationship with your added 'index.html' in ad-test folder.
If you want your ad-test html to be recognised by react, you need to make it a component of app.js and use react-router to give it a pathname.
It is very simple.
First, install react-router-dom;
Second, set up react-router-dom;refer to https://reacttraining.com/react-router/web/guides/quick-start
Third, give your add-test component a pathname.Your js code should look something like this:
<Route path='/ad-test' component={AdTest} />
IMPORTANT:
After you deploy your app, always remember you just built a single-page application.
You only have one html in your app.
Please make sure when you test your app after you deployed you must tell your service provider that no matter what pathname a user inputs in the address bar you always redirect it to the index.html
The build stage includes the public folder:
If you have a picture in the public folder, and this picture was imported to other components it will be shown after you run npm run build
Hope it helps.
Have you tried playing with webserver configurations? It is usually setup to redirect all traffic to index.html. Maybe exclude your static html path from redirection?
Place test-page.html in public folder like
public/path-to-static-html/test-page.html
Configure webserver for
directing all traffic to index.html EXCEPT /path-to-static-html which
will be directed to test-page.html.
For example, in case of Apache
you will be setting the DirectoryIndex directive.
When I updated my site, run npm run build and upload the new files to the server I am still looking the old version of my site.
Without React, I can see the new version of my site with cache-busting. I do this:
Previous file
<link rel="stylesheet" href="/css/styles.css">
New file
<link rel="stylesheet" href="/css/styles.css?abcde">
How can I do something like this or to achieve cache busting with create react app?
There are many threads in the GitHub of create react app about this but no one has a proper/simple answer.
EDIT: create-react-app v2 now have the service worker disabled by default
This answer only apply for CRA v1
This is probably because of your web worker.
If you look into your index.js file you can see
registerServiceWorker();
Never wondered what it did? If we take a look at the file it got imported from we can see
// In production, we register a service worker to serve assets from local cache.
// This lets the app load faster on subsequent visits in production, and gives
// it offline capabilities. However, it also means that developers (and users)
// will only see deployed updates on the "N+1" visit to a page, since previously
// cached resources are updated in the background.
// To learn more about the benefits of this model, read {URL}
// This link also includes instructions on opting out of this behavior.
If you want to delete the web worker, don't just delete the line. Import unregister and call it in your file instead of the register.
import { unregister } from './registerServiceWorker';
and then call
unregister()
P.S. When you unregister, it will take at least one refresh to make it work
I had the same issue when I use create-react-app ( and deploy to heroku). It keeps showing the old version of my app 😡.
I found the problem seems to be on the browser side, it caches my old index.html with its outdated js bundle
You may want to add the following to your server side response header
"Cache-Control": "no-store, no-cache"
or if you are also using heroku create-react-app-buildpack, update the static.json file
"headers": {
"/**": {
"Cache-Control": "no-store, no-cache"
}
}
I think in this way you can still keep that poor service worker 😂, and the latest content will be shown on the N+1 load (second refresh)
Hope this helps...
As mentioned by some of the previous answers here, both the service worker and the (lack of) cache headers can conspire against you when it comes to seeing old versions of your React app.
The React docs state the following when it comes to caching:
Using Cache-Control: max-age=31536000 for your build/static
assets, and Cache-Control: no-cache for everything else is a safe
and effective starting point that ensures your user's browser will
always check for an updated index.html file, and will cache all of
the build/static files for one year. Note that you can use the one
year expiration on build/static safely because the file contents
hash is embedded into the filename.
As mentioned by #squarism, older versions of create-react-app defaulted to opt-out of service worker registration, while newer versions are opt-in. You can read more about that in the official docs. It's quite a straightforward process to match you configuration to the latest template if you started with an older version of create-react-app and you want to switch to the new behaviour.
Related questions:
How to avoid caching for create-react-app
ReactJS: How to prevent browser from caching static files?
how to clear browser cache in reactjs
If your problem is with resources statically referenced in index.html, such as .css files or additional .js files (e.g. configuration files), you can declare a React environment variable, assign a unique value to it and reference it in your index.html file.
In your build script (bash):
REACT_APP_CACHE_BUST={e.g. build number from a CI tool} npm run build
In your index.html:
<link rel="stylesheet" href="%PUBLIC_URL%/index.css?cachebust=%REACT_APP_CACHE_BUST%" />
The variable name has to start with REACT_APP_. More about environment variables in React: https://facebook.github.io/create-react-app/docs/adding-custom-environment-variables.
It appears that they changed from opt-out to opt-in with regards to the service worker. Here's the commit that changed the README and it has examples similar to Kerry G's answer:
https://github.com/facebook/create-react-app/commit/1b2813144b3b0e731d8f404a8169e6fa5916dde4#diff-4e6ec56f74ee42069aac401a4fe448ad