Version 4.0.0 of the still-widely-used jQuery JavaScript library is now available. Celebrated as the first major release in nearly 10 years, jQuery 4.0.0 features support for trusted types and a new, slimmer build.
Announced January 17, the newest version of the jQuery JavaScript library can be downloaded from jquery.com. Trusted types in jQuery 4.0.0 ensure that HTML in the TrustedHTML interface can be input to jQuery manipulation methods in compliance with a browser’s Content Security Policy (CSP) required-trusted-types-for directive. In addition, while some AJAX requests already were using to avoid any CSP errors caused by inline scripts. There still are a few cases where XHR is used for asynchronous script requests, such as when the "headers" option is passed, but tag is used whenever possible.
jQuery 4.0.0 also debuts with a slimmer build, with the removal of deferred objects and callbacks. Deferreds have long-supported the Promises A+ standard for interoperable JavaScript promises; however, in most cases, native promises, available in all jQuery-supported browsers but IE 11, can be used. And while deferred objects have some extra features that native promises do not support, most usage can be migrated to Promise methods, according to the announcement. For developers who must support IE 11, it is best to use the main build or add a polyfill for native promises. IE 10 and older versions are not supported in jQuery 4.0.0.
