function configure()

in js/reveal.js [422:508]
57 lines of code
11 McCabe index (conditional complexity)

	function configure( options ) {

		const oldConfig = { ...config }

		// New config options may be passed when this method
		// is invoked through the API after initialization
		if( typeof options === 'object' ) Util.extend( config, options );

		// Abort if reveal.js hasn't finished loading, config
		// changes will be applied automatically once ready
		if( Reveal.isReady() ===  false ) return;

		const numberOfSlides = dom.wrapper.querySelectorAll( SLIDES_SELECTOR ).length;

		// The transition is added as a class on the .reveal element
		dom.wrapper.classList.remove( oldConfig.transition );
		dom.wrapper.classList.add( config.transition );

		dom.wrapper.setAttribute( 'data-transition-speed', config.transitionSpeed );
		dom.wrapper.setAttribute( 'data-background-transition', config.backgroundTransition );

		// Expose our configured slide dimensions as custom props
		dom.viewport.style.setProperty( '--slide-width', config.width + 'px' );
		dom.viewport.style.setProperty( '--slide-height', config.height + 'px' );

		if( config.shuffle ) {
			shuffle();
		}

		Util.toggleClass( dom.wrapper, 'embedded', config.embedded );
		Util.toggleClass( dom.wrapper, 'rtl', config.rtl );
		Util.toggleClass( dom.wrapper, 'center', config.center );

		// Exit the paused mode if it was configured off
		if( config.pause === false ) {
			resume();
		}

		// Iframe link previews
		if( config.previewLinks ) {
			enablePreviewLinks();
			disablePreviewLinks( '[data-preview-link=false]' );
		}
		else {
			disablePreviewLinks();
			enablePreviewLinks( '[data-preview-link]:not([data-preview-link=false])' );
		}

		// Reset all changes made by auto-animations
		autoAnimate.reset();

		// Remove existing auto-slide controls
		if( autoSlidePlayer ) {
			autoSlidePlayer.destroy();
			autoSlidePlayer = null;
		}

		// Generate auto-slide controls if needed
		if( numberOfSlides > 1 && config.autoSlide && config.autoSlideStoppable ) {
			autoSlidePlayer = new Playback( dom.wrapper, () => {
				return Math.min( Math.max( ( Date.now() - autoSlideStartTime ) / autoSlide, 0 ), 1 );
			} );

			autoSlidePlayer.on( 'click', onAutoSlidePlayerClick );
			autoSlidePaused = false;
		}

		// Add the navigation mode to the DOM so we can adjust styling
		if( config.navigationMode !== 'default' ) {
			dom.wrapper.setAttribute( 'data-navigation-mode', config.navigationMode );
		}
		else {
			dom.wrapper.removeAttribute( 'data-navigation-mode' );
		}

		notes.configure( config, oldConfig );
		focus.configure( config, oldConfig );
		pointer.configure( config, oldConfig );
		controls.configure( config, oldConfig );
		progress.configure( config, oldConfig );
		keyboard.configure( config, oldConfig );
		fragments.configure( config, oldConfig );
		slideNumber.configure( config, oldConfig );

		sync();

	}