Javascript Module - Import (Es Module)

The import statement for a es module

The ES6 import is:

• a function for dynamic import (performed at runtime time)
• or a statement for static import (performed at build time)

that is used to import:

• functions,
• objects
• or primitives

that have been exported from:

• an external ES module,
• another module such as commonCommonJS and AMD modules.
• etc.

import Member from "ModuleName";

var Member = require("ModuleName").default;

@import url('http://getbootstrap.com/dist/css/bootstrap.css');

• Import the default member. It is possible to have a default export

import defaultMember from "module-name"; 
import defaultMember, { member [ , [...] ] } from "module-name";
import defaultMember, * as name from "module-name";

• Import an entire module namespace object where the properties are the module’s exports with the alias 'name'. 'name' is inserted into the current scope.

import * as name from "module-name";
// if the “module-name” module exports a function named foo(), you can write: 
name.foo()

• Import a single member of a module. This inserts member into the current scope.

import { member } from "module-name";
import { member as alias } from "module-name";

• Import multiple members of a module.

import { member1 , member2 } from "module-name";
import { member1 , member2 as alias2 , [...] } from "module-name";

• Import an entire module for side effects only, without importing any bindings.

import "module-name";

See Javascript - Dynamic Import (Module, Json)

• Supported:

// Via the http(s) scheme
import {foo} from 'https://example.com/.../bar.js';
// Full Qualified
import {foo} from '/foo/bar.js';
// Relative
import {foo} from './bar.js';
import {foo} from '../bar.js';

• Supported using NODE_PATH in some module loader

import {foo} from 'bar.js';
import {foo} from 'foo/bar.js';

• Module:

// --file.js--
function getJSON(url, callback) {
  let xhr = new XMLHttpRequest();
  xhr.onload = function () { 
    callback(this.responseText) 
  };
  xhr.open('GET', url, true);
  xhr.send();
}

export function getUsefulContents(url, callback) {
  getJSON(url, data => callback(JSON.parse(data)));
}

• Import

import { getUsefulContents } from 'myModuleFile.js';
getUsefulContents('http://www.example.com', data => {
  doSomethingUseful(data);
});

Import Cannot Use Outside A Module

• Reference/Statements/import