With ES6, I can import several exports from a file like this:
import {ThingA, ThingB, ThingC} from 'lib/things';
However, I like the organization of having one module per file. I end up with imports like this:
import ThingA from 'lib/things/ThingA';
import ThingB from 'lib/things/ThingB';
import ThingC from 'lib/things/ThingC';
I would love to be able to do this:
import {ThingA, ThingB, ThingC} from 'lib/things/*';
or something similar, with the understood convention that each file contains one default export, and each module is named the same as its file.
Is this possible?
I don't think this is possible, but afaik the resolution of module names is up to module loaders so there might a loader implementation that does support this.
Until then, you could use an intermediate "module file" at lib/things/index.js that just contains
export * from 'ThingA';
export * from 'ThingB';
export * from 'ThingC';
and it would allow you to do
import {ThingA, ThingB, ThingC} from 'lib/things';
Just a variation on the theme already provided in the answer, but how about this:
In a Thing,
export default function ThingA () {}
In things/index.js,
export {default as ThingA} from './ThingA'
export {default as ThingB} from './ThingB'
export {default as ThingC} from './ThingC'
Then to consume all the things elsewhere,
import * as things from './things'
things.ThingA()
Or to consume just some of things,
import {ThingA,ThingB} from './things'
The current answers suggest a workaround but it's bugged me why this doesn't exist, so I've created a babel plugin which does this.
Install it using:
npm i --save-dev babel-plugin-wildcard
then add it to your .babelrc with:
{
"plugins": ["wildcard"]
}
see the repo for detailed install info
This allows you to do this:
import * as Things from './lib/things';
// Do whatever you want with these :D
Things.ThingA;
Things.ThingB;
Things.ThingC;
again, the repo contains further information on what exactly it does, but doing it this way avoids creating index.js files and also happens at compile-time to avoid doing readdirs at runtime.
Also with a newer version you can do exactly like your example:
import { ThingsA, ThingsB, ThingsC } from './lib/things/*';
works the same as the above.
You now can use async import():
import fs = require('fs');
and then:
fs.readdir('./someDir', (err, files) => {
files.forEach(file => {
const module = import('./' + file).then(m =>
m.callSomeMethod();
);
// or const module = await import('file')
});
});
Great gugly muglys! This was harder than it needed to be.
Export one flat default
This is a great opportunity to use spread (... in { ...Matters, ...Contacts } below:
// imports/collections/Matters.js
export default { // default export
hello: 'World',
something: 'important',
};
// imports/collections/Contacts.js
export default { // default export
hello: 'Moon',
email: 'hello#example.com',
};
// imports/collections/index.js
import Matters from './Matters'; // import default export as var 'Matters'
import Contacts from './Contacts';
export default { // default export
...Matters, // spread Matters, overwriting previous properties
...Contacts, // spread Contacts, overwriting previosu properties
};
// imports/test.js
import collections from './collections'; // import default export as 'collections'
console.log(collections);
Then, to run babel compiled code from the command line (from project root /):
$ npm install --save-dev #babel/core #babel/cli #babel/preset-env #babel/node
(trimmed)
$ npx babel-node --presets #babel/preset-env imports/test.js
{ hello: 'Moon',
something: 'important',
email: 'hello#example.com' }
Export one tree-like default
If you'd prefer to not overwrite properties, change:
// imports/collections/index.js
import Matters from './Matters'; // import default as 'Matters'
import Contacts from './Contacts';
export default { // export default
Matters,
Contacts,
};
And the output will be:
$ npx babel-node --presets #babel/preset-env imports/test.js
{ Matters: { hello: 'World', something: 'important' },
Contacts: { hello: 'Moon', email: 'hello#example.com' } }
Export multiple named exports w/ no default
If you're dedicated to DRY, the syntax on the imports changes as well:
// imports/collections/index.js
// export default as named export 'Matters'
export { default as Matters } from './Matters';
export { default as Contacts } from './Contacts';
This creates 2 named exports w/ no default export. Then change:
// imports/test.js
import { Matters, Contacts } from './collections';
console.log(Matters, Contacts);
And the output:
$ npx babel-node --presets #babel/preset-env imports/test.js
{ hello: 'World', something: 'important' } { hello: 'Moon', email: 'hello#example.com' }
Import all named exports
// imports/collections/index.js
// export default as named export 'Matters'
export { default as Matters } from './Matters';
export { default as Contacts } from './Contacts';
// imports/test.js
// Import all named exports as 'collections'
import * as collections from './collections';
console.log(collections); // interesting output
console.log(collections.Matters, collections.Contacts);
Notice the destructuring import { Matters, Contacts } from './collections'; in the previous example.
$ npx babel-node --presets #babel/preset-env imports/test.js
{ Matters: [Getter], Contacts: [Getter] }
{ hello: 'World', something: 'important' } { hello: 'Moon', email: 'hello#example.com' }
In practice
Given these source files:
/myLib/thingA.js
/myLib/thingB.js
/myLib/thingC.js
Creating a /myLib/index.js to bundle up all the files defeats the purpose of import/export. It would be easier to make everything global in the first place, than to make everything global via import/export via index.js "wrapper files".
If you want a particular file, import thingA from './myLib/thingA'; in your own projects.
Creating a "wrapper file" with exports for the module only makes sense if you're packaging for npm or on a multi-year multi-team project.
Made it this far? See the docs for more details.
Also, yay for Stackoverflow finally supporting three `s as code fence markup.
Similar to the accepted answer but it allows you to scale without the need of adding a new module to the index file each time you create one:
./modules/moduleA.js
export const example = 'example';
export const anotherExample = 'anotherExample';
./modules/index.js
// require all modules on the path and with the pattern defined
const req = require.context('./', true, /.js$/);
const modules = req.keys().map(req);
// export all modules
module.exports = modules;
./example.js
import { example, anotherExample } from './modules'
If you are using webpack. This imports files automatically and exports as api namespace.
So no need to update on every file addition.
import camelCase from "lodash-es";
const requireModule = require.context("./", false, /\.js$/); //
const api = {};
requireModule.keys().forEach(fileName => {
if (fileName === "./index.js") return;
const moduleName = camelCase(fileName.replace(/(\.\/|\.js)/g, ""));
api[moduleName] = {
...requireModule(fileName).default
};
});
export default api;
For Typescript users;
import { camelCase } from "lodash-es"
const requireModule = require.context("./folderName", false, /\.ts$/)
interface LooseObject {
[key: string]: any
}
const api: LooseObject = {}
requireModule.keys().forEach(fileName => {
if (fileName === "./index.ts") return
const moduleName = camelCase(fileName.replace(/(\.\/|\.ts)/g, ""))
api[moduleName] = {
...requireModule(fileName).default,
}
})
export default api
I've used them a few times (in particular for building massive objects splitting the data over many files (e.g. AST nodes)), in order to build them I made a tiny script (which I've just added to npm so everyone else can use it).
Usage (currently you'll need to use babel to use the export file):
$ npm install -g folder-module
$ folder-module my-cool-module/
Generates a file containing:
export {default as foo} from "./module/foo.js"
export {default as default} from "./module/default.js"
export {default as bar} from "./module/bar.js"
...etc
Then you can just consume the file:
import * as myCoolModule from "my-cool-module.js"
myCoolModule.foo()
Just an other approach to #Bergi's answer
// lib/things/index.js
import ThingA from './ThingA';
import ThingB from './ThingB';
import ThingC from './ThingC';
export default {
ThingA,
ThingB,
ThingC
}
Uses
import {ThingA, ThingB, ThingC} from './lib/things';
Nodejs ? Do like this:
Create a folder with index.js, in index file, add this:
var GET = require('./GET');
var IS = require('./IS');
var PARSE = require('./PARSE');
module.exports = { ...GET, ...IS, ...PARSE};
And, in file GET.js, or IS.js export as normal:
module.exports = { /* something as you like */}
ANd now, you need only including index.js like:
const Helper = require('./YourFolder');
Helper will include all of function in YourFolder.
Good day!
This is not exactly what you asked for but, with this method I can Iterate throught componentsList in my other files and use function such as componentsList.map(...) which I find pretty usefull !
import StepOne from './StepOne';
import StepTwo from './StepTwo';
import StepThree from './StepThree';
import StepFour from './StepFour';
import StepFive from './StepFive';
import StepSix from './StepSix';
import StepSeven from './StepSeven';
import StepEight from './StepEight';
const componentsList= () => [
{ component: StepOne(), key: 'step1' },
{ component: StepTwo(), key: 'step2' },
{ component: StepThree(), key: 'step3' },
{ component: StepFour(), key: 'step4' },
{ component: StepFive(), key: 'step5' },
{ component: StepSix(), key: 'step6' },
{ component: StepSeven(), key: 'step7' },
{ component: StepEight(), key: 'step8' }
];
export default componentsList;
You can use require as well:
const moduleHolder = []
function loadModules(path) {
let stat = fs.lstatSync(path)
if (stat.isDirectory()) {
// we have a directory: do a tree walk
const files = fs.readdirSync(path)
let f,
l = files.length
for (var i = 0; i < l; i++) {
f = pathModule.join(path, files[i])
loadModules(f)
}
} else {
// we have a file: load it
var controller = require(path)
moduleHolder.push(controller)
}
}
Then use your moduleHolder with dynamically loaded controllers:
loadModules(DIR)
for (const controller of moduleHolder) {
controller(app, db)
}
I was able to take from user atilkan's approach and modify it a bit:
For Typescript users;
require.context('#/folder/with/modules', false, /\.ts$/).keys().forEach((fileName => {
import('#/folder/with/modules' + fileName).then((mod) => {
(window as any)[fileName] = mod[fileName];
const module = new (window as any)[fileName]();
// use module
});
}));
if you don't export default in A, B, C but just export {} then it's possible to do so
// things/A.js
export function A() {}
// things/B.js
export function B() {}
// things/C.js
export function C() {}
// foo.js
import * as Foo from ./thing
Foo.A()
Foo.B()
Foo.C()
Related
I'm trying to create some dynamic components.
I have this method:
//makeComponent.ts
export default function makeComponent(module) {
return {
setup(_props, { slots }) {
return () => h('div', { class: Object.values(module) }, slots);
},
}
}
Then I call it In a file (index.js) inside my components' folder.
//components/index.ts
import {makeComponent} from './makeComponent';
import nameModule from './styles/name.module.styl';
export const Name = makeComponent(nameModule);
My problem is this doesn't work with Nuxt's auto-import.
Is there any way to achieve this with auto-import?
Thanks in advance for any clues on that.
I am running Vue3 with vite and can't write any tests for components that use the ElementPlus library. Something else needs to be injected apparently but I don't know how to do that.
I have the following dateControl.test.js:
import { describe, expect, test } from 'vitest';
import { ref } from 'vue';
import DateCtrl from '#/components/DateCtrl.vue';
import { mount } from "#vue/test-utils";
import ElementPlus from "element-plus";
describe("DateCtrl.vue", () => {
const messages = {
"en-US" : {
strings: {
placeholder: 'a',
label: 'b'
}
}
};
const locale = "en-US";
const data = ref ({
date: ''
});
test ("Arrange DateCtrl", async () => {
const component = mount(DateCtrl, {
props: {
vModel: data.value.date,
modelValue: data.value.date,
labelLoc: "label",
className: "w1x5",
placeholderLoc: "date"
},
global: {
plugins: [ElementPlus],
mocks: {
$t: (msg) => {
const params = msg.split('.');
return messages[locale][params[0]][params[1]];
}
}
}
});
//fails on previous lines.
expect(typeof component !== "undefined", "component created").toBeTruthy();
let h3Text = component.findAll('h3')[0].element.innerHTML;
expect(component.findAll('.form').length === 1, "form element rendered").toBeTruthy();
expect(h3Text === "d", "locale strings correct").toBeTruthy();
});
});
It doesn't even get to the "expect" tests, fails with message:
Error: Cannot find module 'C:\source\mySite\node_modules\dayjs\plugin\customParseFormat'
imported from
C:\source\mySite\node_modules\element-plus\es\components\date-picker\src\date-picker.mjs
Did you mean to import dayjs/plugin/customParseFormat.js?
This bit seems to indicate that node expects you to use .js extension and element is not doing that.
Error: Cannot find module 'C:\source\mySite\node_modules\dayjs\plugin\customParseFormat'
imported from
C:\source\mySite\node_modules\element-plus\es\components\date-picker\src\date-picker.mjs
Did you mean to import dayjs/plugin/customParseFormat.js?
I'm guessing this is because you may be running an older node version. Element requires at least node v16.
I have this problem too.
It seems that this problem is already solved in this pull request - https://github.com/element-plus/element-plus/pull/6811
My i18n boot file
import { boot } from 'quasar/wrappers';
import { LocalStorage } from 'quasar';
import messages from 'src/i18n';
import { createI18n } from 'vue-i18n';
const storedLang = LocalStorage.getItem('anty-locale');
const i18n = createI18n({
locale: storedLang && storedLang === 'en' ? 'en-US' : 'ru-RU',
messages,
});
export default boot(({ app }) => {
app.use(i18n);
});
export { i18n };
when I am trying to import in vuex js file like this
import { useI18n } from 'vue-i18n';
const { t } = useI18n({ useScope: 'global' });
I occur an error SyntaxError: Must be called at the top of a setup function
import i18n from 'boot/i18n';
i18n.t('common.user') //also doesn't work
Is there any correct way to import i18n in .js/.ts file?
I fixed like this and it worked.
import { i18n } from 'boot/i18n';
i18n.global.t('common.user'); // it works
I'm using create-react-app for a multi-language project.
I want to use some library like "cssJanus" or "rtlcss" to convert the Sass generated CSS file into a separate file and then use that newly generated file when I switch to another language.
Here's how my index.js looks like ...
import React from "react";
import ReactDOM from "react-dom";
import * as serviceWorker from "./serviceWorker";
import { BrowserRouter as Router } from "react-router-dom";
import { Provider } from "react-redux";
import App from "./App";
import { configureStore } from "./store/configureStore";
const store = configureStore();
ReactDOM.render(
<Provider store={store}>
<Router>
<App />
</Router>
</Provider>,
document.getElementById("root")
);
serviceWorker.unregister();
And here's how my "App.js" looks like ...
import React, { Component } from "react";
import "./App.scss";
import { Route, Switch } from "react-router-dom";
import SignIn from "./features/signin/SignIn";
class App extends Component {
render() {
return (
<>
<Switch>
<Route path="/" exact component={SignIn} />
</Switch>
</>
);
}
}
export default App;
As you can see I'm using "./App.scss" file that simply have a bunch of #import statements to another ".scss" files in the "./src/css/" directory ...
/* autoprefixer grid: on */
#import "css/reset";
#import "css/variables";
#import "css/global";
I need your advice on how to do that. How to convert the generated CSS from App.scss to RTL into their own .css file and switch between them and the original generated CSS based on a change in the global state.
I searched a lot for something like this but with no luck.
Or if you have a better approach I'm all ears.
Here is a simple solution that requires ejecting and adding a lightweight webpack-rtl-plugin.
After running
npx create-react-app react-rtl
cd react-rtl
yarn eject
yarn add -D webpack-rtl-plugin #babel/plugin-transform-react-jsx-source
Go to config/webpack.config.js and make some tweaks:
// import the plugin
const WebpackRTLPlugin = require('webpack-rtl-plugin')
// ...
module: { ... }
plugins: [
// ...,
// use the plugin
new WebpackRTLPlugin({ diffOnly: true })
].filter(Boolean),
// ...
On this stage, if you run yarn build and look up build/static/css folder, you should hopefully see additional .rtl.css file that contains your rtl styles.
Then we need to tell webpack to use MiniCssExtractPlugin.loader for development as well so it will serve styles through link tags instead of inline styles:
// common function to get style loaders
const getStyleLoaders = (cssOptions, preProcessor) => {
const loaders = [
isEnvDevelopment && { loader: MiniCssExtractPlugin.loader }, // <-- use this
// isEnvDevelopment && require.resolve('style-loader'), <-- instead of this
and don't forget the plugin, lol:
module: { ... }
plugins: [
// ...,
// isEnvProduction && <-- comment this out
new MiniCssExtractPlugin({
// Options similar to the same options in webpackOptions.output
// both options are optional
filename: 'static/css/[name].[contenthash:8].css',
chunkFilename: 'static/css/[name].[contenthash:8].chunk.css',
}),
// ...
].filter(Boolean),
And from here you can finally grab your default stylesheet href and use to insert rtl styles. Here's how you could implement it:
class RtlCssBundleService {
constructor() {
this.rtlApplied = false
this.rtlStyles = [];
this.ltrStyles = Array.from(
document.querySelectorAll('link[rel="stylesheet"]')
)
}
insert = () => {
if (this.rtlApplied) { return }
this.rtlApplied = true
if (this.rtlStyles.length) {
return this.rtlStyles.forEach(style => {
document.body.appendChild(style)
})
}
this.rtlStyles = this.ltrStyles.map(styleSheet => {
const link = document.createElement("link")
link.href = styleSheet.href.replace(/\.css$/, '.rtl.css')
link.rel = "stylesheet"
document.body.appendChild(link)
return link
})
}
detach = () => {
this.rtlApplied = false
this.rtlStyles.forEach(style => {
document.body.removeChild(style)
})
}
toggle = () => {
return this.rtlApplied
? this.detach()
: this.insert()
}
}
const rtlStyles = new RtlCssBundleService()
export default rtlStyles
Then use this from any of your components.
So anyway, I'm sure I've missed something and maybe that is a terrible approach, but it seems to work and here is the demo
If you use flexbox and css grid they have RTL support built in. Then use CSS Logical Properties for margin, padding, border, etc. If that is not enough, then you can use [dir="rtl"] .your-class as a fallback.
Now you don't have two separate css files to maintain.
Here is a cross browser margin-right example.
-webkit-margin-end: 25px;
margin-inline-end: 25px;
#supports (not (-webkit-margin-end: 0)) and (not (margin-inline-end: 0)) {
margin-right: 25px;
}
You could wrap that up into a mixin for easier use across your app.
Looking around there is a library called react-with-direction from airbnb that provides a DirectionProvider - component you could wrap your components in based on the language. Hope that helps.
Given this subscription, and the React Component below, how do I pass the subscription data in as props 'searchTerms'? Most of the documentation I can find refers to using mixins, but as far as I understand this is an anti pattern in ES6. Thanks!
constructor() {
super();
this.state = {
subscription: {
searchResult: Meteor.subscribe("search", searchValue)
}
}
}
render() {
return (
<div>
<SearchWrapper
searchTerms={this.state.subscription.searchResult}
/>
</div>
)
}
There are a couple options when it comes to creating containers in Meteor. My personal favorite is react-komposer.
Here's what your container would look like using react-komposer. Note that a container is simply a component that just passes data, and in the case of Meteor, provides reactivity.
After npm install --save react-komposer, create a container using:
import { Meteor } from 'meteor/meteor';
import React from 'react';
import { composeWithTracker } from 'react-komposer';
import Component from '../components/Component.jsx';
import { Collection } from '../../api/collection/collection.js';
// Creates a container composer with necessary data for component
const composer = ( props, onData ) => {
const subscription = Meteor.subscribe('Collection.list');
if (subscription.ready()) {
const collection = Collection.find().fetch(); // must use fetch
onData(null, {collection});
}
};
// Creates the container component and links to Meteor Tracker
export default composeWithTracker(composer)(Component);
The standard way of doing this is to use the react-meteor-data package.
meteor add react-meteor-data
Then create a container as follows:
import { Meteor } from 'meteor/meteor';
import { createContainer } from 'meteor/react-meteor-data';
import SearchWrapper from '../pages/SearchWrapper.jsx';
import { SearchResults } from '../../api/searchResults.js';
export default SearchResultContainer = createContainer(({ params }) => {
const { searchValue } = params;
const searchHandle = Meteor.subscribe('search', searchValue);
const loading = !searchHandleHandle.ready();
const results = SearchResults.find().fetch();
const resultsExist = !loading && !!list;
return {
loading,
results,
resultsExist,
};
}, SearchWrapper);
The returned object from the container is available as props in the wrapped component - SearchWrapper.