[Webpack 5] Dynamic import is not working with promise externals, fix #11197: dynamic import promise externals. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. We can notice from this diagram the 4 chunks that have been created(one for each file in the animals directory), along with the main parent chunk(called index). The diagrams have been made with Excalidraw. [5] ./sources/views/admin/win_add_subsuser.js 3.19 KiB {0} [built] In old versions of Webpack (v1), we commonly used the AMD require or the specific Webpack require.ensure to dynamic load modules. Just an update for those going down this path: If you are using React, I would recommend react-loadable, makes it extremely easy to do dynamic imports on a per-component basis a lot of large companies use it. Sorry for delay. privacy statement. In this article we will learn about demistifying webpack's 'import' function: using dynamic arguments. Configuring webpack can be tricky when there are so many things going on. Webpack Bundler , . To begin, you'll need to install imports-loader: npm install imports-loader --save-dev or yarn add -D imports-loader or pnpm add -D imports-loader Given you have this file: example.js $("img").doSomeAwesomeJqueryPluginStuff(); Then you can inject the jquery value into the module by configuring the imports-loader using two approaches. As the import is a function receiving a string, we can do powerful things like loading modules using expressions. Is there a single-word adjective for "having exceptionally strong moral principles"? Using fetch I could load the images dynamically from the public folder and start webpack without getting ever again a memory issue. to your account, __webpack_require__ is called with result of promise external when it's is loaded as dynamic import, which results with error Modules are reusable chunks of code built from your app's JavaScript, node_modules, images, and CSS styles, which are packaged to be easily used on your website. [3] ./sources/models/m_subscriptions.js 2.38 KiB {0} [built] - A preloaded chunk starts loading in parallel to the parent chunk. This feature relies on Promise internally. Additional tools: -. When expanded it provides a list of search options that will switch the search inputs to match the current selection. The label can occur before a function declaration or a variable declaration. Lets suppose you have an app that has different behavior and visuals in some features for mobile to desktop. Including hashes related to the file contents to their names allows to invalidate them on the client-side. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Webpack is a static module bundler for JavaScript applications. If you are using Webpack 4.0, code splitting requires minimal configuration, Here, the return import construct is used for modules which need to be loaded dynamically. See this thread to the problem https://github.com/webpack/webpack/issues/5747. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Then I started going through all of the plugins in the Babel configuration. It's subject to automatic issue closing if there is no activity in the next 15 days. [7] ./sources/views/admin/win_changerole.js 3.13 KiB {0} [built] Let's solve solution for this, @Miaoxingren reproducible repo still has the problem? I'm creating react component libraries, which I'm then using to lazy load as routes, but while this works with a static import: const LazyComponent = lazy(() => import('my-package')), const packageOne = 'my-package' An array of this kind contains very useful information to webpack, such as: the chunk id(it will be used in the HTTP request for the corresponding JS file), the module id(so that it knows what module to require as soon as the chunk has finished loading) and, finally, the module's exports type(it used by webpack in order to achieve compatibility when using other types of modules than ES modules). *\\.js$/ and it will be tested against all the files which reside in the animals/ directory(e.g regExp.test('./cat.js')). The upside of this way of loading modules is that you don't overload the main chunk with all the possible modules that can match the import's expression, but rather they are put in another chunk which can be loaded lazily. reactjs ComponentA myComponents ComponentA adsbygoogl Note that setting webpackIgnore to true opts out of code splitting. Dynamic import from node_modules is not working, https://github.com/Miaoxingren/webpack-issue-8934, dynamic import for chunk in node_modules is not working as expected, https://github.com/younabobo/webpack-dynamic-import-test, https://webpack.js.org/api/module-methods/#dynamic-expressions-in-import. Webpack provides a method of templating the filenames using bracketed strings called substitutions. Therefore, the use of dynamic import is necessary. As far as the ./animals/${fileName}.js segment is concerned, each ${fileName} refers to a dynamic part and it will be replaced with /. It can also traverse nested directories(this is the default behaviour) and once the files are properly discovered, webpack will proceed based on the chosen mode. You might be wondering now: isn't it a waste of resources, if webpack creates multiple chunks when in the end there will be only one chunk that matches the path? webpackChunkName: A name for the new chunk. By adding comments to the import, we can do things such as name our chunk or select different modes. With the above ES proposal the keyword import gets more power and turns also into a function which returns a Promise: The above code will load the foo module at runtime, and resolving it, will log the default export of the module. Webpack Babel. to your account, I made a vue component package my-custom-comp, which contains dynamic import: Refresh the page, check Medium 's site status, or find something interesting to read. Check out the guide for more information on how webpackPrefetch works. Available since webpack 5.0.0-beta.18. The problem is if you want to dynamically load a file, in this case, an image, Webpack by default generate a chunk for that module, something similar to this: The big issue with that is when you request dynamic imported images, it will do a network request to get the chunk and then another one to get the image, adding unnecessary overhead to your app. As imports are transformed to require.ensure there are no more magic comments. rev2023.3.3.43278. @sokra Could you be more specific? How to solve this problem?. Well occasionally send you account related emails. But it took approximately 10 minutes to load. If you use import() with older browsers, remember to shim Promise using a polyfill such as es6-promise or promise-polyfill. This feature relies on Promise internally. webpack version: 5.0.0-beta.22 // Do something when module is available // Do something when module was loaded before // You can perform dynamic resolves ("context"). This is wrapped in a JavaScript object and executed using node VM. Recovering from a blunder I made while emailing a professor. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. We can try to directly require the cat module(without pressing the Load cat chunk first), but we will end up with an error, saying the module is not available: However, if we load the cat chunk first and then require the module, everything should be working fine: The takeaway from this section is that when using the weak mode, it is expected of the resource to be already at hand. It's subject to automatic issue closing if there is no activity in the next 15 days. As we can control the loading strategy, we can also use the magic comments to control the generated chunk names too by simply doing this: Instead of numbers, Webpack will use the chosen names to the generated chunks. How do you ensure that a red herring doesn't violate Chekhov's gun? Otherwise, an error will be thrown. webpack --env.production true, Hash: 40911497abda454cf910 Adding asssets outside of the module system. Include a dependency without executing it. // Dynamically loading the `cat.js` module. This is only needed in rare cases for compatibility! Thanks for contributing an answer to Stack Overflow! Making statements based on opinion; back them up with references or personal experience. Since webpack 2.6.0, the placeholders [index] and [request] are supported within the given string to an incremented number or the actual resolved filename respectively. Synchronously retrieve a module's ID. require.ensure() is specific to webpack and superseded by import(). My problem was closely related to #7417, @younabobo It is documented, we can't build module from x, it is runtime value and it is impossible to detect https://webpack.js.org/api/module-methods/#dynamic-expressions-in-import, @ufon You need this #11127, we will implement it for webpack@5. webpackIgnore: Disables dynamic import parsing when set to true. But it took approximately 10 minutes to load. provide a real example: Webpack Dynamic Import Expression Not Working, Adding asssets outside of the module system, https://github.com/webpack/webpack/issues/5747, How Intuit democratizes AI development across teams through reusability. *.js(loosely).In the upcoming sections we will explore what happens once these files have been figured. // And here the chunk is loaded. Webpack: Common chunks for code shared between Webworker and Web code? Hey, I noticed that Webpack just put numbers to generated chunks. The nature of simulating nature: A Q&A with IBM Quantum researcher Dr. Jamie We've added a "Necessary cookies only" option to the cookie consent popup. But what is the difference between prefetch and preload?. [0] ./node_modules/css-loader!./node_modules/less-loader/dist/cjs.js!./sources/styles/anytime.css 1.18 KiB {0} [built] to get it working. Underlying modules can then be easily resolved later on: If mode is set to 'lazy', the underlying modules will be loaded asynchronously: The full list of available modes and their behavior is described in import() documentation. Nothing elaborate until now, it's just what we've been doing in other sections, namely specifying the mode we want the import function to operate, which in this case is weak. The traversal starts from the first static part of the provided path(in this case it is ./animals) and in each step it will read the files from the current directory and will test the RegExp object against them. This feature relies on Promise internally. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. When using CommonJS module syntax, this is the only way to dynamically load dependencies. { type:"header", template:"Dynamically imported UI" }. This looks like an obvious problem and with that many libraries out there, someone must have found a solution I guess. Dynamic imports stopped working in Webpack v4. To learn more, see our tips on writing great answers. Do I need a thermal expansion tank if I already have a pressure tank? What Is the Difference Between 'Man' And 'Son of Man' in Num 23:19? Now if we want to use the lion module, I should not see a new request, but only a confirmation that the lion module has been executed: Here's a diagram to supplement what's been accumulated so far: We've saved this section until last because of its peculiarities. The public folder is useful as a workaround for a number of less common cases: You have thousands of images and need to dynamically reference their paths. What is the expected behavior? And consider adding service workers with a good caching strategy. In this way, you only load the code that you need. If you run npm run build and check the dist/main.js file, the map will look a bit different: Here, the pattern is this: { filename: [moduleId, moduleExportsMode, chunkId] }. A prefetched chunk is downloaded in browser idle time. or on Twitter at @heypankaj_ and/or @time2hack. That's because the chunk will be served from a cache internally maintained by webpack and the required module will be retrieved from the array/object of modules where webpack records them. Using it in an async function may not have the expected effect. webpack.config.js. My app is made to be accessible from a lot of specific platforms like mobile, desktop, tablet, VR and can be even more in the future!. The result of the dynamic import is an object with all the exports of the module. The way we're currently doing things, the cat module is not loaded from anywhere else, so this is why we're facing an error. How to use Slater Type Orbitals as a basis functions in matrix method correctly? He suggested me to use the public folder as described in the create-react-app readme and to not import the SVGs via webpack: Although it worked with webpack@3. I am trying to setup dynamic svg imports since my app uses many icons and I don't want to impact startup time to load all icons i.e. Have a question about this project? NOTE: This plugin is included in @babel/preset-env, in ES2020. Therefore a cache in the runtime exists. Suppose there is a directory structure that looks like this: By using the import function in our application code: webpack will generate a chunk for each file in the animals directory. Webpack adds a really nice feature to the dynamic imports, the magic comments. In this article, we will dive deep into the concept of dynamic expressions when it comes to the import function and hopefully, at the end, you will be more acquainted with the range of possibilities that this webpack's feature provides. The compiler will ensure that the dependency is available in the output bundle. From this list of plugins, the only plugin that might be the culprit is dynamic-import-webpack, A small plugin to make dynamic imports i.e. Keep in mind that you will still probably need babel for other ES6+ features. Webpack Dynamic Import babel-plugin-syntax-dynamic-import . - Coco Jun 21, 2018 at 20:36 Already have this plugin installed, and it still does not work. I am having same problem even with webpack 5, // Uncaught (in promise) Error: Cannot find module 'x' at lib lazy ^. @Miaoxingren Please create minimum reproducible test repo. [contenthash].chunk.js, But still no luck! How can we prove that the supernatural or paranormal doesn't exist? Does a summoned creature play immediately after being summoned by a ready action? In this example, the resulting RegExp object will be /^\\.\\/. If the current behavior is a bug, please provide the steps to reproduce. Which you can see here: GitHub - airbnb/babel-plugin-dynamic-import-webpack: Babel plugin to transpile import() to require.ensure, for Webpack. Dynamic import is the way to import some chunk of code on demand. The file loader will basically map the emitted file path inside a module. How Webpack Handles Dynamic Imports with Variable Paths | JavaScript in Plain English Write Sign up Sign In 500 Apologies, but something went wrong on our end. This section covers all methods available in code compiled with webpack. Sign up for a free GitHub account to open an issue and contact its maintainers and the community. For example, with core-js@3: webpack.config.js const config = { entry: [ Lets now explore those strategies in greater detail. If you think this is still a valid issue, please file a new issue with additional information. First of all, I've gone through #150 before creating this issue. privacy statement. Version 2 of webpack supports ES6 module syntax natively, meaning you can use import and export without a tool like babel to handle this for you. Asset Size Chunks Chunk Names Have a question about this project? Calls to import() are treated as split points, meaning the requested module and its children are split out into a separate chunk. https://webpack.js.org/guides/code-splitting/#dynamic-imports, https://babeljs.io/docs/plugins/syntax-dynamic-import/#installation. Where does this (supposedly) Gibson quote come from? You can take a look into the descriptions in more detail here. [41] ./sources/locales sync ^\.\/.$ 181 bytes {0} [built] webpackChunkName not effective and working with Babel? Version: webpack 4.28.2 Sign in Sign up for a free GitHub account to open an issue and contact its maintainers and the community. If you want to check the how-to make a lazy-loaded single page application (SPA) using the discussed dynamic import, you can check out two of my previous articles on this subject. The other modules whose values are null are called orphan modules. Use webpackPrefetch: true magic comment with webpackChunkName . Using the webpackInclude and webpackExclude options allows you to add regex patterns that reduce the number of files that webpack will bundle for this import. If the name of the animal can't be found in the animals directory, an error will be thrown. So now I am using this fetch library, which was already included in the config (generated by create-react-app after ejecting) webpack generated code (added line breaks for clarity): part .then((m) => __webpack_require__.t(m, 7)) seems to be unnecessary. By default webpack import all files from views folder, which can conflict with code splitting. The goal of CommonJS is to specify an ecosystem for JavaScript outside the browser. fish.js Special thanks Max Koretskyi for reviewing this article and for providing extremely valuable feedback.