MediaWiki:Common.js

	 * Adds show/hide-button to navigation bars.
	 *
	 * @param {jQuery} $content
	 */
	function createNavigationBarToggleButton( $content ) {
		var j, navChild, navToggle, navToggleText, isCollapsed,
			indexNavigationBar = 0;
		// Iterate over all < div >-elements
		var $divs = $content.find( 'div.NavFrame:not(.mw-collapsible)' );
		$divs.each( function ( i, navFrame ) {
			indexNavigationBar++;
			navToggle = document.createElement( 'a' );
			navToggle.className = 'NavToggle';
			navToggle.setAttribute( 'id', 'NavToggle' + indexNavigationBar );
			navToggle.setAttribute( 'href', '#' );
			$( navToggle ).on( 'click', $.proxy( toggleNavigationBar, null, indexNavigationBar ) );

			isCollapsed = $( navFrame ).hasClass( 'collapsed' );
			/**
			 * Check if any children are already hidden.  This loop is here for backwards compatibility:
			 * the old way of making NavFrames start out collapsed was to manually add style="display:none"
			 * to all the NavPic/NavContent elements.  Since this was bad for accessibility (no way to make
			 * the content visible without JavaScript support), the new recommended way is to add the class
			 * "collapsed" to the NavFrame itself, just like with collapsible tables.
			 */
			for ( navChild = navFrame.firstChild; navChild !== null && !isCollapsed; navChild = navChild.nextSibling ) {
				if ( $( navChild ).hasClass( 'NavPic' ) || $( navChild ).hasClass( 'NavContent' ) ) {
					if ( navChild.style.display === 'none' ) {
						isCollapsed = true;
					}
				}
			}
			if ( isCollapsed ) {
				for ( navChild = navFrame.firstChild; navChild !== null; navChild = navChild.nextSibling ) {
					if ( $( navChild ).hasClass( 'NavPic' ) || $( navChild ).hasClass( 'NavContent' ) ) {
						navChild.style.display = 'none';
					}
				}
			}
			navToggleText = document.createTextNode( isCollapsed ? navigationBarShow : navigationBarHide );
			navToggle.appendChild( navToggleText );

			// Find the NavHead and attach the toggle link (Must be this complicated because Moz's firstChild handling is borked)
			for ( j = 0; j < navFrame.childNodes.length; j++ ) {
				if ( $( navFrame.childNodes[ j ] ).hasClass( 'NavHead' ) ) {
					navToggle.style.color = navFrame.childNodes[ j ].style.color;
					navFrame.childNodes[ j ].appendChild( navToggle );
				}
			}
			navFrame.setAttribute( 'id', 'NavFrame' + indexNavigationBar );
		} );
	}

	mw.hook( 'wikipage.content' ).add( createNavigationBarToggleButton );