I have tried asking on Super User community before, but didn't get any answers so I'm trying my luck here.
I'm running an Apache web server and decided to host a React application. I have a nano-react-app folder which contains the files shown below. I can render the website in debug mode so I know my code is working properly. But when I go online, I get this error :
Uncaught SyntaxError: Cannot use import statement outside a module (index.js:1)
which points to the line import React from 'react'; in index.js. To be honest, I don't really understand what the error is telling me so I don't know where and how to look. All I could figure out is that my Index.js file — with a capital i — is called from index.html with a lowercase i and it changes nothing locally but on server-side it returns this error when capitalizing i:
GET http://mywebsite/src/Index.js net::ERR_ABORTED 404 (Not Found)
Now.. I have read in another SO question that I should add type="module" when calling index.js in script tag but now I get this error :
Uncaught SyntaxError: Unexpected token '<' (index.js:5)
I would highly appreciate any solutions... Thanks!
Browsers don't support JSX natively. You need to transpile your code to JavaScript by creating a production build. How you do that depends on the toolchain you have selected and is covered in the React documentation.
Related
I have several years experience as a backend dev, but my frontend experience has been limited to very basic bugfixes in an established frontend codebase. So I have been trying to set up a "hello world" one page app using React Bootstrap so I can learn.
I attempted to just copy the set up in the React Bootstrap Basic Example code sandbox, but I am getting the following console error:
Uncaught SyntaxError: expected expression, got '<'
index.js:8:16
I have my current code available at this github repo.
Pretty sure I've made some n00b mistake, but I guess a n00b has to start somewhere.
By default the browser does not support JSX sintax (IE: <App />). There is a lot of ways to get this working, but I recommend create-react-app
More about JSX: https://reactjs.org/docs/introducing-jsx.html
Any time I import Amplify into my React Native project's App.js file, I get the following error:
TypeError: null is not an object (evaluating 'keys.filter')
Here is how I'm importing it:
I run the project using Expo only. If I comment the import Amplify line out, any other files which use anything related to Amplify cause the same error to occur.
Initially, when I was loading this project for the first time, I had other errors to deal with like first needing to create the aws-exports.js file. I copied this over from an old project (Because this is meant to be a re-do of another project that's already set up). Once I included that file I had to update a few lines in that file because of an improper reference to Linking from expo. Once I fixed that, it throw this error I'm referencing here. Now, even if I delete the aws-exports file it will throw this error as soon as Amplify is imported into the App.js file.
-- Update
I've found where the error is occurring. Some of my code gets executed but the error happens inside of the reactnative.js file when syncing between two memory software.
I've tried to reproduce this error inside a fresh react application by copying the package.js file and then importing Amplify into the App.js file but it doesn't throw this error.
Here is a screenshot of where the error is taking place. I'm still trying to figure out how to pinpoint where in my code this error begins.
According to Expo, you have to follow these steps
it would be best if you imported Amplify
import Amplify from '#aws-amplify/core'
All you need to follow those steps it sees the configuration issue result data is not coming that's why it gives a null value and crashes.
Follow steps below will fix your problem
https://blog.expo.dev/how-to-build-cloud-powered-mobile-apps-with-expo-aws-amplify-2fddc898f9a2
The problem seems to be resolved by changing the slug attribute in the react app.json file. I changed the slug from being a camel case to an all lower case slug.
After this the error has gone away for what seems permanent. I've been able to replicate the error in small sample apps. I don't understand why this causes these errors.
I'm probably missing something really obvious but I'm not very accustomed to GitHub or React so I'd love some advice.
My GitHub is here:
https://github.com/SarahACollins/PortfolioWebsite
I've tried publishing the website here:
https://sarahacollins.github.io/PortfolioWebsite/
and it just produces a blank page. I've tried several different ways of fixing (changing the homepage, moving the index.html to the front, etc.) but can't figure out what's wrong. Any help would be appreciated.
In the developer console it says:
Uncaught SyntaxError: Cannot use import statement outside a module. Looking at the location of the error shows that it is node.js code.:
import React from 'react';
You need to compile your react source code and create a .js file for the client from it.
In a React project, I am trying to run the app on a live server in the web browser. However when I command CD Ravenous to go to the right file and npm start, the browser gives me the following error:
./src/index.js
Module not found: Can't resolve './App' in '/Users/mauricemarkslag/ravenous/src'
I've checked if the imports have been filled in correctly, and that should be the case now I guess. However the error doesn't seem to be fixed with this code:
Code file
Folder structure
Does anybody know what I might do wrong?
You have a typo, you should use ./app.css instead of ./App.css, and I am assuming that the file that you put in your question is app.js.
I've been having trouble getting react-pdf to work properly in my react app that I created using 'create-react-app'. From various github comments on the react-pdf page, it seems that there's an issue setting up the workerSrc in React applications that were created with 'create-react-app'.
One work around that seemed to solve the issue (temporarily) was to copy the pdf.worker.js file from the node-modules/build/pdfjs-dist/build folder and place it in the public folder of my react app. Then in my index.js file put the following code:
import {pdfjs} from 'react-pdf'
window.PDFJS.workerSrc = process.env.PUBLIC_URL + '/pdf.worker.js'
This worked just fine for a week, until I installed a new module into my application with npm. Now, I'm getting the same error I did in the beginning, and nothing has changed:
index.js:14 Uncaught TypeError: Cannot set property 'workerSrc' of undefined
These were the initial comments that helped me narrow down the error:
https://github.com/facebook/create-react-app/issues/1574#issuecomment-280436498
https://github.com/wojtekmaj/react-pdf/issues/291
but now that it's back I'm kind of at a loss for ideas. Has anyone else experienced this and been able to solve it? Any help would be greatly appreciated!
Based on what I have seen in the docs and in forums, it appears you should be altering the global PDFJS object.
PDFJS.workerSrc, instead of window.workerSrc.
I managed to get this working by loading the worker from CDN.
import { Document, Page, pdfjs } from 'react-pdf';
pdfjs.GlobalWorkerOptions.workerSrc=//cdnjs.cloudflare.com/ajax/libs/pdf.js/${pdfjs.version}/pdf.worker.js