MediaWiki:Gadget-ExternalLinksInNewTab.js

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// add option in Special:Preferences to open external links in a new tab;
// to force this setting for all users, see
// https://www.mediawiki.org/wiki/Manual:$wgExternalLinkTarget

mw.hook( 'wikipage.content' ).add( function ( $content ) {
	$content.find( 'a.external' ).each( function( _, externalLink ) {
		externalLink.setAttribute( 'target', '_blank' );
	} );
} );