Does order of imports in Webpack entry file matter - javascript

I'm having an issue where I have two components that I'm importing into my entry file "index.js" - depending on which I have as the first import, the second will not work and I get an error "Target Container is not a DOM Element." What am I missing? Why will the Proforma component only render if it's first in the index.js, and why does the App component try to load anyways when I browse to the page that the Proforma component loads (when it successfully loads and the console still has the above error)?
The index.js file looks like:
import App from "./components/App.js";
import Proforma from "./components/property_detail/proforma.js";
In that scenario, the page displaying App.js works - but still attempts to load Proforma despite that element not appearing anywhere in the App.js code. The same happens when I change the order of the elements and load the page that includes "proforma.js", which is just:
import React, { Component } from "react";
import ReactDOM from "react-dom";
class Proforma extends React.Component {
render() {
return (
<p>Proforma Page</p>
);
}
}
ReactDOM.render(
<Proforma />,
document.getElementById('proforma')
);
The template page that the Proforma component should be rendered on:
{% load static %}
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="{% static './css/bulma/bulma.css' %}">
<title>Test Proforma </title>
</head>
<body>
<section class="section">
<div class="container">
<div id="proforma"><!-- React --></div>
</div>
</section>
{% load static %}
<script src="{% static 'frontend/main.js' %}"></script>
</body>
</html>
For good measure, the package.json file and webpack.config look like:
I'm building the file with this:
package.json
{
"main": "index.js",
"scripts": {
"dev": "webpack --mode development
./simple_proforma_react/frontend/src/index.js --output
./simple_proforma_react/frontend/static/frontend/main.js",
....
}
webpack.config.js
module.exports = {
module: {
rules: [
{
test: /\.js$/,
exclude: /node_modules/,
use: {
loader: "babel-loader"
}
}
]
}
};

Do you have a ReactDom.render in your proforma component file, as well as in your app.js/index.js file? That might cause a problem

Related

Element UI icons wont show up using Laravel Mix

I made a simple website using Vue and Element UI. I used Laravel Mix to compile my code.
During development, the icons are showing up but when I run "npm run prod" and upload it to Github Pages they wont show up.
This is my webpack.mix.js
let mix = require('laravel-mix');
mix.js('src/js/app.js', 'public/')
.sass('src/styles/app.scss', 'public/')
.babelConfig({})
.disableNotifications();
I am using on demand components and followed this doc so my root vue file looks like this:
import Vue from 'vue'
import store from './vuex'
import router from './vue-router'
import Element from 'element-ui';
import 'element-ui/lib/theme-chalk/index.css';
import lang from 'element-ui/lib/locale/lang/es'
import locale from 'element-ui/lib/locale'
locale.use(lang)
Vue.use(Loading.directive);
Vue.component(Select.name, Select)
Vue.component(Option.name, Option)
Vue.component(Input.name, Input)
Vue.component(Icon.name, Icon)
new Vue({
el: '#app',
router,
store,
});
Following the same doc, I added a .babelrc file on my root directory but I didn't managed to get it working with the preset es2015 so I used #babel/preset-env instead. I dont actually know how to properly use Babel so the whole error might be over here but idk.
{
"presets": [["#babel/preset-env", { "modules": false }]],
"plugins": [
[
"component",
{
"libraryName": "element-ui",
"styleLibraryName": "theme-chalk"
}
]
]
}
I noticed something weird, when I run npm run prod, the output shows something like this:
The fonts folder and the needed fonts are being copied to my root directory, so when its on Github it makes a request to the root domain, the root folder, the right url should be over (I guess?) /h3lltronik.github.io/my-site/ but it is on /h3lltronik.github.io/.
Just in case is needed, Im using the icons like this:
<el-input v-model="search" prefix-icon="el-icon-search" class="filter_input element-input bordered" #input="onChangeSearch"
placeholder="Search for a country..."></el-input>
And this is my index.html
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>H3lltronik</title>
<link rel="stylesheet" href="./public/app.css">
</head>
<body>
<div id="app" :class="modeClass">
<transition name="el-fade-in">
<router-view class="content-body"></router-view>
</transition>
</div>
<script src="./public/app.js"></script>
</body>
</html>

Next.js - import css file does not work

I am creating a project with react, redux and next.js, and want to import CSS files in js.
I followed instructions in next.js/#css and next-css, but find out that CSS styles do not work.
My code is as follow:
pages/index.js:
import React from 'react'
import "../style.css"
class Index extends React.Component {
render() {
return (
<div className="example">Hello World!</div>
);
}
}
export default Index
next.config.js:
const withCSS = require('#zeit/next-css')
module.exports = withCSS()
style.css:
.example {
font-size: 50px;
color: blue;
}
package.json:
{
"name": "my-app",
"version": "0.1.0",
"private": true,
"dependencies": {
"#zeit/next-css": "^0.1.5",
"next": "^6.0.0",
"react": "^16.3.2",
"react-dom": "^16.3.2",
"react-redux": "^5.0.7",
"react-scripts": "1.1.4",
"redux": "^4.0.0",
"redux-devtools": "^3.4.1"
},
"scripts": {
"test": "react-scripts test --env=jsdom",
"eject": "react-scripts eject",
"dev": "next",
"build": "next build",
"start": "next start"
}
}
Questions:
1. There is an "Uncaught SyntaxError" in Chrome, but it seems to not affect the rendering of the page. But I still wondering the reason and the solution. index.js error in chrome is below img
2. As shown in Chrome, there's no "example" class, which means the style.css file is not loaded. Am I missing anything? no CSS file in chrome
Thanks in advance.
EDIT 2: As of Next.js > 10, you can import a global CSS file into _app.js, and you can use CSS modules in your components. More in the Next.js docs.
EDIT: As of Next.js 7, all you have to do to support importing .css files is to register the withCSS plugin in your next.config.js. Start by installing the plugin as dev dependency:
npm install --save-dev #zeit/next-css
Then create the next.config.js file in your project root and add the following to it:
// next.config.js
const withCSS = require('#zeit/next-css')
module.exports = withCSS({/* my next config */})
You can test that this is working by creating a simple page and importing some CSS. Start by creating a CSS file:
// ./index.css
div {
color: tomato;
}
Then create the pages folder with an index.js file. Then you can do stuff like this in your components:
// ./pages/index.js
import "../index.css"
export default () => <div>Welcome to next.js 7!</div>
You can also use CSS modules with a few lines of config. For more on this check out the documentation on nextjs.org/docs/#css.
Deprecated: Next.js < 7:
You'll also need to create a _document.js file in your pages folder and link to the compiled CSS file. Try it out with the following content:
// ./pages/_document.js
import Document, { Head, Main, NextScript } from 'next/document'
export default class MyDocument extends Document {
render() {
return (
<html>
<Head>
<link rel="stylesheet" href="/_next/static/style.css" />
</Head>
<body>
<Main />
<NextScript />
</body>
</html>
)
}
}
The stylesheet is compiled to .next/static/style.css which means that the CSS file is served from /_next/static/style.css, which is the value of the href attribute in the link tag in the code above.
As for the first question, it's probably Chrome not understanding the import syntax. Try to enable the Experimental Web Platform flag in chrome:flags and see if that solves it.
For anyone who comes here ,the new Next JS supports CSS out of the box. The catch is that for modules (components), they must be named as the component. So, if you have a header inside a components directory, it must be named header.module.css
built-in-css-module-support-for-component-level-styles
Add {name}.css to src/static/styles/.
Then modify the Head in src/pages/_document.js to include the following link:
<Head>
<link href="/static/styles/{name}.css" rel="stylesheet">
</Head>
for next above 9.3, global css is written in "styles/globals.css" and you can import it to _app.js
import "../styles/globals.css";
Then for each component, you can write its own css and import it into the component. Pay attention to the naming:nameOfFile.module.css
Let's say you have "product.js" component and "product.module.css". you want to load css from "product.css" into "product.js"
import classes from "./product.module.css" // assuming it's in the same directory
you put all class names into product.module.css. Assume you have .main-product in product.module.css. Inside product.js, let's say you have a div to style
<div className={classes.main-product} > </div>
with the css module feature, you can use the same className in other components and it wont conflict. Because when next.js compiles, it will hash the name of the className, using its module. So hashed values of same classnames from different modules will be same
you need create to custom _document.js file.
Custom document when adding css will look like:
import React from "react";
import Document, { Head, Main, NextScript } from "next/document";
export default class MyDocument extends Document {
render() {
const { buildManifest } = this.props;
const { css } = buildManifest;
return (
<html lang="fa" dir="rtl">
<Head>
{css.map(file => (
<link rel="stylesheet" href={`/_next/${file}`} key={file} />
))}
</Head>
<body>
<Main />
<NextScript />
</body>
</html>
);
}
}
As Zeit said :
Create a /static folder at the same level the /pages folder.
In that folder put your .css files
In your page components import Head and add a to your CSS.
import Head from 'next/head'
function IndexPage() {
return (
<div>
<Head>
<title>My page title</title>
<meta name="viewport" content="initial-scale=1.0, width=device-width" />
</Head>
<p>Hello world!</p>
</div>
)
}
export default IndexPage
And that's it, this way Next.js should render the link tag in the head of the page and the browser will download the CSS and apply it.
Thanks Sergiodxa at Github for this clear solution.
If you use next.js do this.
create next.config.js in root projects
const withCSS = require('#zeit/next-css');
function HACK_removeMinimizeOptionFromCssLoaders(config) {
console.warn(
'HACK: Removing `minimize` option from `css-loader` entries in Webpack config',
);
config.module.rules.forEach(rule => {
if (Array.isArray(rule.use)) {
rule.use.forEach(u => {
if (u.loader === 'css-loader' && u.options) {
delete u.options.minimize;
}
});
}
});
}
module.exports = withCSS({
webpack(config) {
HACK_removeMinimizeOptionFromCssLoaders(config);
return config;
},
});
Don't forget to restart the server
Global CSS Must Be in Your Custom <App>
Why This Error Occurred
An attempt to import Global CSS from a file other than pages/_app.js was made.
Global CSS cannot be used in files other than your Custom due to its side-effects and ordering problems.
Possible Ways to Fix It
Relocate all Global CSS imports to your pages/_app.js file.
Or, update your component to use local CSS (Component-Level CSS) via CSS Modules. This is the preferred approach.
Example:
// pages/_app.js
import '../styles.css'
export default function MyApp({ Component, pageProps }) {
return <Component {...pageProps} />
}
Set this to false if your app works directly with the web 5 package.
module.exports = {
// Webpack 5 is enabled by default
// You can still use webpack 4 while upgrading to the latest version of
// Next.js by adding the "webpack5: false" flag
webpack5: false,
}
You can use webpack 4.
yarn add webpack#webpack-4

React - Uncaught Error: Target container is not a DOM element

I'm new to react.
My error is:
Uncaught Error: Target container is not a DOM element
I've Googled this plenty of times and find people who have this error:
Uncaught Error: Invariant Violation: _registerComponent(...): Target container is not a DOM element.
Mine doesn't contain:
_registerComponent(...):
Here are my files:
index.html
<html>
<head>
<meta charset="utf-8">
<title>React</title>
</head>
<body>
<div id="root"></div>
<script src="./bundle.js"></script>
</body>
</html>
index.jsx
import React from 'react';
import ReactDOM from 'react-dom';
ReactDOM.render(
<div>
<h1>Hello World!</h1>
</div>,
document.getElementById('root')
);
webpack.config.js
const path = require('path');
module.exports = {
context: path.join(__dirname, 'src'),
entry: './index.jsx',
output: {
path: path.join(__dirname, 'public'),
filename: './bundle.js'
},
module: {
loaders: [
{ test: /\.js$/, loader: 'babel-loader', exclude: /node_modules/ },
{ test: /\.jsx$/, loader: 'babel-loader', exclude: /node_modules/ },
],
},
resolve: {
modules: [
path.join(__dirname, 'node_modules')
]
}
};
The most common issue I found people were having with this error is that they put <script> in the head or before the <div>. Yet I don't do neither of these so I have no idea what the problem is.
I'm definitely a little late to the party here, but would like to post an answer for those who want to use webpack-dev-middleware instead of circumventing it.
The problem, for me, was that basic setup for webpack-dev-middleware is shown in the webpack docs using html-webpack-plugin with a default configuration. This plugin dynamically generates a new index.html file along with your bundle.js on save, so even though I wrote an index.html file that contained <div id="root"></div>, that wasn't the one that was being served to the browser. I was able to verify this by running /node_modules/.bin/webpack and watching the output in my public path directory.
My solution is as follows:
Add a configuration object to the declaration of the WebpackHtmlPlugin:
plugins: [
new HtmlWebpackPlugin({
title: "boilerplate",
template: path.join(__dirname, "pathto", "template.html"),
inject: "body",
}),
],
(This sets the title of the template file, its location, and directs html-webpack-pluginto push all script tags into the bottom of the body element of the generated file.) The template is as follows:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title><%= htmlWebpackPlugin.options.title %></title>
</head>
<body>
<div id="root"></div>
</body>
</html>
More info can be found here:
https://webpack.js.org/plugins/html-webpack-plugin/
https://github.com/jantimon/html-webpack-plugin#options
Thanks to Axnyff for his help as it resolved my question. The problem was with a dependency I was using, webpack-dev-middleware.

Import Unity file in React project

I am having trouble loading a Unity file in my React project. I thought if I add the file in index.html I would be able to use UnityLoader anywhere in the project as shown below:
index.html
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Game</title>
</head>
<body>
<div id="app">
</div>
<script src="UnityLoader.js"></script>
</body>
</html>
Unity.js
class Unity extends Component {
render() {
return (
<div id="unity">
{UnityLoader.instantiate('unity', 'unity/index.html')}
</div>
);
}
}
However, I get an error saying UnityLoader is undefined.
Do I need to use some sort of
import { UnityLoader } from 'UnityLoader'
in Unity.js? The issue is that UnityLoader is an external JS file and does not export anything.
Why not installing React-Unity via npm and then import it into your component?
import React, { Component } from 'react';
import { Unity } from 'react-unity-webgl';
export class App extends Component {
render() {
return (<div className="app">
<Unity src="Build/myGame.json" />
</div>)
}
}
Don't forget to add a script tag to load the UnityLoader.js file, exported by Unity in your base html file.
<script src="build_unity/Build/UnityLoader.js"></script>
<script src="compiled/bundle.js"></script>

webpack, process env variable in index.html

I have a react app which has an entrypoint of my app.jsx and I am adding segment.io to my build, however I would like to set it's API key as an process.env variable. I am having trouble with how to do this with webpack because my entry point is not the index.html.
I am trying to see if there is a way so I can (on the index.html) do something like this
<script type="text/javascript">
..segment script loading here + (process.env.MY_SEGMENT_KEY)}();
</script>
But I am not sure how to get it so I can process env variables at the index.html level.
In app.jsx I am toggling the code like :
if (process.env.MY_SEGMENT_KEY) {
....
}
and this works fine because I have access to the vars at this point. I would like to also conditionally load the script on the index.html. Anyone know if this is possible? Thanks!
Just load analytics in your JSX file as follow:
import React from 'react';
import ReactDOM from 'react-dom';
import App from './App';
if (process.env.MY_SEGMENT_KEY) {
window.analytics.load(process.env.MY_SEGMENT_KEY);
}
ReactDOM.render(
<App />,
document.getElementById('root')
);
Your index.html file should look like that:
<!DOCTYPE html>
<html>
<head>
...
<title>My App</title>
<script type="text/javascript">
!function(){var analytics=window.analytics=window.analytics||[];if(!analytics.initialize)if(analytics.invoked)window.console&&console.error&&console.error("Segment snippet included twice.");else{analytics.invoked=!0;analytics.methods=["trackSubmit","trackClick","trackLink","trackForm","pageview","identify","reset","group","track","ready","alias","debug","page","once","off","on"];analytics.factory=function(t){return function(){var e=Array.prototype.slice.call(arguments);e.unshift(t);analytics.push(e);return analytics}};for(var t=0;t<analytics.methods.length;t++){var e=analytics.methods[t];analytics[e]=analytics.factory(e)}analytics.load=function(t){var e=document.createElement("script");e.type="text/javascript";e.async=!0;e.src=("https:"===document.location.protocol?"https://":"http://")+"cdn.segment.com/analytics.js/v1/"+t+"/analytics.min.js";var n=document.getElementsByTagName("script")[0];n.parentNode.insertBefore(e,n)};analytics.SNIPPET_VERSION="4.0.0";
}}();
</script>
</head>
<body>
<div id="root">
</div>
</body>
</html>

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