Menu
Is Dynamic Script Tag Addition is Asynchronous? Like dynamically including set of JavaScript files from a different domain..
374
Dynamic scripts behave as “async” by default. That is: They don't wait for anything, nothing waits for them. The script that loads first – runs first (“load-first” order).
Asynchronous code: Scripts are loaded and executed parallelly in one go, wherein scripts are loaded concurrently as other web page components. Asynchronous scripts do not wait for other functions or statements to be executed.
If the async attribute is set, the script is downloaded in parallel to parsing the page, and executed as soon as it is available. The parsing of the page is interrupted once the script is downloaded completely, and then the script is executed, before the parsing of the rest of the page continues.
Async - means execute code when it is downloaded and do not block DOM construction during downloading process. Defer - means execute code after it's downloaded and browser finished DOM construction and rendering process.
Yes, it is asynchronous. Dynamic <script> injection always results in the browser loading an external resource via the DOM (e.g. just like stylesheets, images, flash), which must happen asynchronously to avoid browser lockup.
Are you looking at JSONP ("JSON with Padding") by any chance? It uses dynamic script tag injection. It's more and more part of discussions about "AJAX", and the fact that it is impossible to do synchronous JSONP (like synchronous XmlHttpRequest) is often overlooked.
200
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
