What is load-script?
The load-script npm package is a utility for dynamically loading external JavaScript files into a web page. It provides a simple and efficient way to include scripts on the fly, which can be useful for various purposes such as loading third-party libraries, modularizing code, or conditionally loading scripts based on user interactions or other conditions.
What are load-script's main functionalities?
Basic Script Loading
This feature allows you to load an external JavaScript file by providing its URL. The callback function handles the success or failure of the script loading process.
const loadScript = require('load-script');
loadScript('https://example.com/script.js', function (err, script) {
if (err) {
console.error('Script loading failed:', err);
} else {
console.log('Script loaded successfully:', script.src);
}
});
Loading Scripts with Attributes
This feature allows you to load a script with additional attributes such as 'async' and 'defer'. These attributes can control the script's loading behavior and execution timing.
const loadScript = require('load-script');
loadScript('https://example.com/script.js', { async: true, defer: true }, function (err, script) {
if (err) {
console.error('Script loading failed:', err);
} else {
console.log('Script loaded successfully with attributes:', script.src);
}
});
Error Handling
This feature demonstrates how to handle errors when a script fails to load. The callback function receives an error object that can be used to log or handle the error appropriately.
const loadScript = require('load-script');
loadScript('https://example.com/nonexistent.js', function (err, script) {
if (err) {
console.error('Failed to load script:', err.message);
} else {
console.log('Script loaded successfully:', script.src);
}
});
Other packages similar to load-script
scriptjs
Script.js is a lightweight library for dynamically loading JavaScript. It offers similar functionality to load-script but with a slightly different API. Script.js allows for chaining multiple script loads and provides a more fluent interface.
requirejs
RequireJS is a JavaScript file and module loader. While it is more complex and feature-rich compared to load-script, it provides advanced capabilities for managing dependencies and modularizing code. It is suitable for larger projects that require a robust module loading system.
headjs
Head.js is a script loader that focuses on optimizing the loading of JavaScript and CSS files. It provides features for parallel loading and execution order control, making it a powerful tool for improving page load performance.
load-script
Dynamic script loading.
Installation
via component
$ component install eldargab/load-script
via npm
$ npm install load-script
API
load-script
appends a script
node to the <head>
element in the dom.
require('load-script')
returns a function of the following interface: function(url[, opts][, cb]) {}
url
Any url that you would like to load. May be absolute or relative.
[, opts]
A map of options. Here are the currently supported options:
async
- A boolean value used for script.async
. By default this is true
.attrs
- A map of attributes to set on the script
node before appending it to the DOM. By default this is empty.charset
- A string value used for script.charset
. By default this is utf8
.text
- A string of text to append to the script
node before it is appended to the DOM. By default this is empty.type
- A string used for script.type
. By default this is text/javascript
.
[, cb]
A callback function of the following interface: function(err, script) {}
where err
is an error if any occurred and script
is the script
node that was appended to the DOM.
Example Usage
var load = require('load-script')
load('foo.js', function (err, script) {
if (err) {
}
else {
console.log(script.src);
}
})
License
MIT