React Webpack proces.env.PUBLIC_URL is undefined - javascript

In my React app, I have added console in src/index.js for process.env as below;
proces.env.PUBLIC_URL // undefined
proces.env.NODE_ENV // "development"
I am not sure why proces.env.PUBLIC_URL is coming as undefined. Anything specific I need to check in my app. I have the webpack config below.
config/webpack.dev.js
const merge = require('webpack-merge');
const path = require('path');
const webpack = require('webpack');
const common = require('./webpack.common');
const srcDirectory = path.resolve(__dirname, '../src');
module.exports = merge(common, {
entry: {
main: ['react-hot-loader/patch', path.join(srcDirectory, 'index.js')]
},
resolve: {
alias: {
}
},
output: {
filename: '[name].bundle.js'
},
mode: 'development',
devtool: 'eval-source-map',
module: {
rules: [
{
test: /\.(js|.ts|tsx)$/,
exclude: /node_modules/,
use: 'babel-loader',
},
{
test: /\.scss$/,
exclude: /node_modules/,
use: [
'style-loader',
'css-loader',
'resolve-url-loader',
{ loader: 'sass-loader', options: { sourceMap: true } }
]
},
{
test: /\.css$/,
use: ['style-loader', 'css-loader']
}
]
},
devServer: {
contentBase: 'src',
hot: true,
port: 3000,
historyApiFallback: {
disableDotRule: true
},
stats: 'minimal',
overlay: true,
proxy: {
'/api/**': {
target: {
port: 8080
},
secure: false
},
'/actuator/**': {
target: {
port: 8080
},
secure: false
}
}
},
plugins: [new webpack.HotModuleReplacementPlugin()]
});
Also below is config/webpack.common.js
const path = require('path');
const webpack = require('webpack');
const CopyWebpackPlugin = require('copy-webpack-plugin');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const srcDirectory = path.resolve(__dirname, '../src');
const srcDirectory1 = path.resolve(__dirname, '../src/public');
const distDirectory = path.resolve(__dirname, '../dist');
module.exports = {
entry: {
main: ['whatwg-fetch', 'raf/polyfill']
},
resolve: {
modules: [srcDirectory, 'node_modules'],
extensions: ['.ts', '.tsx', '.js', '.json', '.html', '.scss', '.css']
},
output: {
path: distDirectory,
publicPath: '/'
},
module: {
rules: [
{
test: /\.(js|.ts|tsx)$/,
exclude: /node_modules/,
use: 'babel-loader',
},
{
test: /\.txt$/,
exclude: /node_modules/,
use: 'raw-loader'
},
{
test: /\.(png|jpg|jpeg|svg|gif|woff|woff2|ttf|eot|ico)(\?v=\d+\.\d+\.\d+)?$/,
use: 'file-loader'
}
]
},
plugins: [
new CopyWebpackPlugin({
patterns: [
{ from: path.join(srcDirectory, 'images'), to: 'images' }
]
}),
new HtmlWebpackPlugin({ template: path.join(srcDirectory, 'index.html') })
]
};

You need to use webpack EnvironmentPlugin.
plugins: [
// ...
new webpack.EnvironmentPlugin(['NODE_ENV', 'DEBUG']),
]

Related

How i can solve the devServer problem in webpack?

I would be grateful for any help or advice. I have compiled the configuration of the webpack, everything works in production mode, but the webpack-dev-server does not see static files and gives the error "Cannot get /". How can I solve this problem? Thank you in advance for the answer. Here is my webpack.config.js
const path = require("path");
const { VueLoaderPlugin } = require("vue-loader");
const { CleanWebpackPlugin } = require("clean-webpack-plugin");
const HTMLWebpackPlugin = require("html-webpack-plugin");
const MiniCssExtractPlugin = require("mini-css-extract-plugin");
const CssMinimizerWebpackPlugin = require("css-minimizer-webpack-plugin");
const TerserWebpackPlugin = require("terser-webpack-plugin");
// const autoprefixer = require("autoprefixer");
const isProd = process.env.NODE_ENV === "production";
const isDev = !isProd;
const optimization = () => {
const config = {
runtimeChunk: "single",
splitChunks: {
cacheGroups: {
vendor: {
test: /[\\/]node_modules[\\/]/,
name: "vendors",
priority: -10,
chunks: "all",
},
},
},
};
if (isProd) {
config.minimizer = [
new CssMinimizerWebpackPlugin(),
new TerserWebpackPlugin(),
];
}
return config;
};
module.exports = {
entry: path.resolve(__dirname, "src", "index.js"),
mode: isProd ? "production" : "development",
output: {
path: path.join(__dirname, "build"),
filename: "[name].[contenthash:8].js",
chunkFilename: "[name].[contenthash:8].js",
publicPath: "./",
},
devtool: isDev ? "source-map" : false,
module: {
rules: [
{
test: /\.js$/,
exclude: /node_modules/,
use: {
loader: "babel-loader",
},
},
{
test: /\.vue$/,
loader: "vue-loader",
},
{
test: /\.(eot|ttf|woff|woff2)(\?\S*)?$/,
loader: "file-loader",
options: {
name: "[name][contenthash:8].[ext]",
},
},
{
test: /\.(png|jpe?g|gif|webm|mp4|svg)$/,
loader: "file-loader",
options: {
name: "[name][contenthash:8].[ext]",
outputPath: "assets/img",
esModule: false,
},
},
{
test: /\.s?css$/,
use: [
"style-loader",
{
loader: MiniCssExtractPlugin.loader,
options: {
esModule: false,
},
},
"css-loader",
],
},
],
},
plugins: [
new VueLoaderPlugin(),
new MiniCssExtractPlugin({
filename: "[name].[contenthash:8].css",
chunkFilename: "[name].[contenthash:8].css",
}),
new HTMLWebpackPlugin({
template: path.join(__dirname, "src", "public", "index.html"),
filename: "start-page.html",
alwaysWriteToDisk: true,
minify: {
collapseWhitespace: isProd,
},
}),
new CleanWebpackPlugin(),
],
resolve: {
alias: {
vue: "#vue/runtime-dom",
},
extensions: ["*", ".js", ".vue", ".json"],
},
optimization: optimization(),
devServer: {
compress: true,
port: 9000,
hot: true,
client: {
overlay: true,
},
},
};
Here is a project folders
According to the doc, you need to set the publicPath in the devServer.
Look at the documentation
module.exports = {
//...
devServer: {
static: {
directory: path.join(__dirname, 'public'),
},
compress: true,
port: 9000,
},
};

How to bundle and minimize JS and CSS files with webpack

I have been trying to use webpack for my project. I have successfully got webpack to compile all of my js into one file correctly. But what i need is for it to also get the css. All of my css is in one file so i figured it would be easy but i cant figure it out. I have tried to split it up into 2 phases CSS_CONFIG and JS_CONFIG
const path = require('path');
const CssMinimizerPlugin = require('css-minimizer-webpack-plugin');
const TerserPlugin = require("terser-webpack-plugin");
var JS_CONFIG = {
entry: path.join(__dirname, 'src/js/main.js'),
resolve: {
alias: {
'/components': path.resolve(__dirname, 'src/components/'),
'/js': path.resolve(__dirname, 'src/js/'),
'/views': path.resolve(__dirname, 'src/views/'),
},
},
optimization: {
minimizer: [
// For webpack#5 you can use the `...` syntax to extend existing minimizers (i.e. `terser-webpack-plugin`), uncomment the next line
new TerserPlugin(),
//new CssMinimizerPlugin(),
],
},
}
var CSS_CONFIG = {
entry:path.join(__dirname,"src/index.html"),
module: {
rules: [
{
test: /.s?css$/,
use: [],
},
],
},
optimization: {
minimize:true,
minimizer: [
// For webpack#5 you can use the `...` syntax to extend existing minimizers (i.e. `terser-webpack-plugin`), uncomment the next line
// `...`,
//new CssMinimizerPlugin(),
],
},
plugins: [],
}
module.exports = [JS_CONFIG, CSS_CONFIG];
This seems like it should be pretty straightforward with webpack but I must not be grasping somthing. Can anyone help me out?
I believe that your CSS_CONFIG should look more like this:
const path = require("path");
const MiniCssExtractPlugin = require("mini-css-extract-plugin");
const RemoveEmptyScriptsPlugin = require('webpack-remove-empty-scripts');
const isDevelopment = process.env.NODE_ENV === 'development'
var config = {
module: {},
};
var cssConfig = Object.assign({}, config, {
devtool: 'source-map',
entry: {
main: path.resolve(__dirname, 'public/css/main.scss'),
fonts: path.resolve(__dirname, 'public/css/fonts.scss'),
app: path.resolve(__dirname, 'public/css/app.scss'),
},
output: {
path: path.resolve(__dirname, 'public/css')
},
performance: {
hints: false
},
plugins: isDevelopment ? [] : [
new RemoveEmptyScriptsPlugin(),
new MiniCssExtractPlugin({
filename: '[name].css',
chunkFilename: '[id].css'
}),
],
module: {
rules:[
// Extracts the compiled CSS from the SASS files defined in the entry
{
test: /\.scss$/,
use: isDevelopment ?
[
'style-loader',
{
loader: 'css-loader',
options: { sourceMap: true, importLoaders: 1, modules: false },
},
{
loader: 'postcss-loader',
options: { sourceMap: true }
},
{
loader: 'resolve-url-loader',
},
{
loader: 'sass-loader',
options: { sourceMap: true }
},
]
: [
{
loader: MiniCssExtractPlugin.loader,
options: {
publicPath: (resourcePath, context) => {
// publicPath is the relative path of the resource to the context
// e.g. for ./css/admin/main.css the publicPath will be ../../
// while for ./css/main.css the publicPath will be ../
return path.relative(path.dirname(resourcePath), context) + "/";
},
},
},
{
loader: 'css-loader',
options: {
importLoaders: 2,
modules: false,
url: false,
},
},
{
loader: 'postcss-loader',
options:
{
postcssOptions:
{
plugins: [
require('postcss-import'),
require('postcss-url')({
url: 'copy',
useHash: true,
hashOptions: { append: true },
assetsPath: path.resolve(__dirname, 'public/assets/')
})
]
}
}
},
{
loader: 'resolve-url-loader',
},
{
loader: 'sass-loader',
options: { sourceMap: true }
},
]
},
/* you may or may not need this
{
test: /\.(woff(2)?|ttf|eot|svg)$/,
use: [
{
loader: 'file-loader',
options: {
name: '[name].[ext]',
outputPath: 'fonts/',
esModule: false,
}
}
]
},
*/
],
}
});
use runs the loaders in order that they are put in the array. So 'style-loader' needs to be executed first. Here is a simple way of achieving the desired result.
const path = require('path');
const CssMinimizerPlugin = require('css-minimizer-webpack-plugin');
const TerserPlugin = require("terser-webpack-plugin");
const MiniCssExtractPlugin = require("mini-css-extract-plugin");
const RemoveEmptyScriptsPlugin = require('webpack-remove-empty-scripts');
const isDevelopment = process.env.NODE_ENV === 'development'
var JS_CONFIG = {
entry: {
main: path.resolve(__dirname, 'src/js/main.js'),
css: path.join(__dirname, 'src/css/main.css'),
},
resolve: {
alias: {
'/components': path.resolve(__dirname, 'src/components/'),
'/js': path.resolve(__dirname, 'src/js/'),
'/views': path.resolve(__dirname, 'src/views/'),
},
},
module: {
rules:[
{
test: /\.css$/,
use:['style-loader','css-loader']
},
],
},
};
module.exports = [JS_CONFIG];

Webpack shows white screen

After I've added webpack in my react app, once the webpack started, it shows the white screen, and the whole bundle gets downloaded at one time. Even though I've done code splitting in react.
my webpack config:
/* eslint-disable no-un`enter code here`def */
const path = require("path");
const HtmlWebpackPlugin = require("html-webpack-plugin");
const HtmlWebpackInjectPreload = require("#principalstudio/html-webpack-inject-preload");
const { CleanWebpackPlugin } = require("clean-webpack-plugin");
module.exports = {
entry: path.resolve(__dirname, './index.js'),
devtool: "inline-source-map",
output: {
path: path.resolve(__dirname, "build"),
filename: "bundle.js",
publicPath: '/'
},
devServer: {
contentBase: path.resolve(__dirname, 'build'),
port: 4000,
hot: true,
},
resolve: {
extensions: [".*",".js", ".jsx", ".css"],
fallback: {
stream: false
}
},
module: {
rules: [
{
test: /\.(js|jsx)$/,
exclude: /(node_modules)/,
use: ["babel-loader"],
},
{
test: /\.css$/,
exclude: /\.module\.css$/,
use: ["style-loader", "css-loader"],
},
{
test: /\.module\.css$/,
use: [
"style-loader",
{
loader: "css-loader",
options: { importLoaders: 2, modules: true },
},
"postcss-loader",
],
},
{
test: /\.(jpe?g|png|gif|woff|woff2|eot|ttf|svg)(\?[a-z0-9=.]+)?$/,
use: [
{
loader: "url-loader",
options: {
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},
},
],
},
],
},
plugins: [
new HtmlWebpackPlugin({
template: path.resolve('./index.html')
}),
new CleanWebpackPlugin(),
new HtmlWebpackInjectPreload({
files: [
{
match: /.*\.woff2$/,
attributes: { as: "font", type: "font/woff2", crossorigin: true },
},
{
match: /\.[a-z-0-9]*.css$/,
attributes: { as: "style" },
},
],
}),
],
};
The attached bundle image also gets larger up to 19MB. What's going wrong I'm not able to figure out.

Need help injecting assets into a compiled index.html file

I'm trying to replace Gulp with WebPAck. I have this WebPack configuration that compiles a Nunjucks template and bundles js code and css code.
Instead of bundling, I'm trying to configure webpack to inject the vendor assets into the index.html header and body.
I looked into a few webpack plugins but it appears none of the work correctly. This is what I have now :
The nunjucks compilation breaks and the individual vendor assets dont get injected.
const BrowserSyncPlugin = require('browser-sync-webpack-plugin');
const CleanWebpackPlugin = require('clean-webpack-plugin');
const CopyWebpackPlugin = require('copy-webpack-plugin');
const ExtraWatchWebpackPlugin = require('extra-watch-webpack-plugin');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');
const NunjucksWebpackPlugin = require('nunjucks-webpack-plugin');
const OptimizeCSSAssetsPlugin = require('optimize-css-assets-webpack-plugin');
const StyleLintPlugin = require('stylelint-webpack-plugin');
const UglifyJsPlugin = require('uglifyjs-webpack-plugin');
const path = require('path');
const nunjuckspages = require('./nunjuckspages');
const HtmlWebpackExternalsPlugin = require('html-webpack-externals-plugin')
const HtmlWebpackPlugin = require('html-webpack-plugin')
module.exports = env => {
const devMode = !env || !env.production;
return {
mode: devMode ? 'development' : 'production',
entry: {
main: './src/index.js',
typescript_demo: './src/typescript_demo.ts',
vendor: './src/vendor.js'
},
output: {
path: path.join(__dirname, 'dist'),
filename: 'assets/js/[name].js',
library: 'MainModule',
},
module: {
rules: [
{
test: /\.(sa|sc|c)ss$/,
use: [
MiniCssExtractPlugin.loader,
{ loader: 'css-loader'},
{ loader: 'postcss-loader', options: { sourceMap: true } },
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{ loader: 'sass-loader', options: { sourceMap: true } }
]
},
{
test: /\.ts(x?)$/,
enforce: 'pre',
exclude: /node_modules/,
use: [
{
loader: 'tslint-loader',
options: { /* Loader options go here */ }
}
]
},
{
test: /\.ts(x?)$/,
exclude: /node_modules/,
use: [
{
loader: 'babel-loader',
query: {
presets: [
'#babel/preset-env'
]
}
},
{
loader: 'ts-loader'
}
]
},
{
enforce: 'pre',
test: /\.js$/,
exclude: /node_modules/,
loader: 'eslint-loader'
},
{
test: /\.js$/,
loader: 'babel-loader',
query: {
presets: [
'#babel/preset-env'
]
}
},
{
test: /\.(png|jpg|gif)$/i,
use: [
{
loader: 'url-loader',
options: {
limit: 8192
}
}
]
},
{
test: /\.(woff(2)?|ttf|eot|svg)(\?v=\d+\.\d+\.\d+)?$/,
use: [{
loader: 'file-loader',
options: {
name: '[name].[ext]',
outputPath: '/assets/fonts/'
}
}]
}
]
},
stats: {
colors: true
},
devtool: 'source-map',
plugins: [
new NunjucksWebpackPlugin({
templates: nunjuckspages
}),
new MiniCssExtractPlugin({
filename: 'assets/css/[name].css'
}),
/// new StyleLintPlugin(),
new BrowserSyncPlugin({
host: 'localhost',
port: 3000,
server: { baseDir: ['dist'] }
}),
new ExtraWatchWebpackPlugin({
dirs: ['templates']
}),
new CopyWebpackPlugin([
// copyUmodified is true because of https://github.com/webpack-contrib/copy-webpack-plugin/pull/360
{ from: 'assets/**/*', to: '.' },
{ from: 'img/*', to: './img' },
], { copyUnmodified: true }),
new CleanWebpackPlugin(),
new HtmlWebpackPlugin({
inject: true,
hash: true,
publicPath: '/',
title: 'TEST1',
template: 'templates/_layouts/layout.html',
showErrors: true
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404 not found ( webpack image )

How can I import an image using this web pack config?
I get the following error in the console after I build the app using yarn build. How can I import the image to the dashboard file from the assets/public folder? (please see image). Thanks in advance.
this the webpack config file.
const webpack = require('webpack');
const path = require('path');
const ExtractTextPlugin = require('extract-text-webpack-plugin');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const CopyWebpackPlugin = require('copy-webpack-plugin');
const extractCSS = new ExtractTextPlugin('[name].fonts.css');
const extractSCSS = new ExtractTextPlugin('[name].styles.css');
const BUILD_DIR = path.resolve(__dirname, 'build');
const SRC_DIR = path.resolve(__dirname, 'src');
console.log('BUILD_DIR', BUILD_DIR);
console.log('SRC_DIR', SRC_DIR);
module.exports = (env = {}) => {
return {
entry: {
index: [SRC_DIR + '/index.js']
},
output: {
path: BUILD_DIR,
filename: '[name].bundle.js',
},
// watch: true,
devtool: env.prod ? 'source-map' : 'cheap-module-eval-source-map',
devServer: {
contentBase: BUILD_DIR,
// port: 9001,
compress: true,
hot: true,
open: true
},
module: {
rules: [
{
test: /\.(js|jsx)$/,
exclude: /node_modules/,
use: {
loader: 'babel-loader',
options: {
cacheDirectory: true,
presets: ['react', 'env']
}
}
},
{
test: /\.html$/,
loader: 'html-loader'
},
{
test: /\.(scss)$/,
use: ['css-hot-loader'].concat(extractSCSS.extract({
fallback: 'style-loader',
use: [
{
loader: 'css-loader',
options: {alias: {'../img': '../public/img'}}
},
{
loader: 'sass-loader'
}
]
}))
},
{
test: /\.css$/,
use: extractCSS.extract({
fallback: 'style-loader',
use: 'css-loader'
})
},
{
test: /\.(png|jpg|jpeg|gif|ico)$/,
use: [
{
// loader: 'url-loader'
loader: 'file-loader',
options: {
name: './img/[name].[hash].[ext]'
}
}
]
},
{
test: /\.(woff(2)?|ttf|eot|svg)(\?v=\d+\.\d+\.\d+)?$/,
loader: 'file-loader',
options: {
name: './fonts/[name].[hash].[ext]'
}
}]
},
plugins: [
new webpack.HotModuleReplacementPlugin(),
new webpack.optimize.UglifyJsPlugin({sourceMap: true}),
new webpack.NamedModulesPlugin(),
extractCSS,
extractSCSS,
new HtmlWebpackPlugin(
{
inject: true,
template: './public/index.html'
}
),
new CopyWebpackPlugin([
{from: './public/img', to: 'img'}
],
{copyUnmodified: false}
)
]
}
};
Please see images below.
What Am I missing here?
Thanks in advance.
first of all , you should import your image like :
import MyImage from '../relative/path/to/your/image'
then use it like:
function App() {
return (
<div className="App">
<img src={MyImage} alt='any kind of description'>
</div>
);
}

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