ES modules can be imported dynamically. This feature is sometimes useful. Let's see how it's done. Let's say we have the following module:
export function func1() {
return '1'
}
export function func2() {
return '2'
}
export default function() {
return 'text';
};
Suppose we want to import this module not immediately, but by some event, for example, by clicking on a button:
btn.addEventListener('click', function() {
});
Let's import a module using
the import
command:
btn.addEventListener('click', function() {
import('./test.js');
});
The import
command returns a
promise as its result:
btn.addEventListener('click', function() {
import('./test.js').then(mod => {
});
});
The object with exported functions will get into the callback variable:
btn.addEventListener('click', function() {
import('./test.js').then(mod => {
let res1 = mod.func1();
let res2 = mod.func2();
console.log(res1, res2);
});
});
What is exported by default will be
in the default
key:
btn.addEventListener('click', function() {
import('./test.js').then(mod => {
let dfn = mod.default();
console.log(dfn);
});
});
It can be destructured when importing:
btn.addEventListener('click', function() {
import('./test.js').then(({func1, func2}) => {
let res1 = func1();
let res2 = func2();
console.log(res1, res2);
});
});
Create a module that exports an array of
the week days names. On a button clicking,
import this module and display the days
of the week as an ul
list.