Customisable slideshow scaffolding using Jekyll and Generators

• Minimalist to encourage running own Javascript inside generators to control slides
• Extensible via plugins
• provides minimal styling so addtional styling can be provided by slide author

An example site is in https://github.com/AdaRoseEdwards/a-slides/tree/master/jekyll-template it has two methods of creating slide content:

• Single page blog post which becomes a slide deck at the push of a button, in which blockquotes get treated as slides and the text around them becomes speakers notes. .* Source
• Each Jekyll post is a treated as a slide in the slide deck. .* Source, part1 index.html .* Source, part2 the posts directory

• include build/a-slides.js and build/a-slides.css in your page.
• when the script is done it converts appropriate DOM into slides.

<div class="a-slides_slide-container">
	<div class="a-slides_slide active" data-slide-id="slide-id-for-deep-linking">
		<div class="dark a-slides_slide-content">
			Slide 1 Content goes here
		</div>
		<div class="a-slides_notes">
			Slide 1 Notes goes here
		</div>
	</div>
	<div class="a-slides_slide active" data-slide-id="slide-the-second-slide">
		<div class="dark a-slides_slide-content">
			Slide 2 Content goes here
		</div>
		<div class="a-slides_notes">
			Slide 2 Notes goes here
		</div>
	</div>
</div>

	const slideData = {'slide-id': {
		setup() {},
		action: function *() {
			this.appendChild(window.MAKE.markdown('# Hello'));
			yield;
			this.appendChild(window.MAKE.markdown('# World'));
		},
		teardown: {
			this.innerHTML = '';
		}
	}};

	new ASlides(slideData, {
		slideContainer: document.querySelector('.a-slides_slide-container'),
		plugins: [
			ASlides.prototype.plugins.markdownTransform, // needs to be run first
			ASlides.prototype.plugins.slideController, // needs to be run before buttons are added to it.
			ASlides.prototype.plugins.deepLinking,
			ASlides.prototype.plugins.interactionKeyboard,
			ASlides.prototype.plugins.interactionTouch({ // has configuration
				use: ['swipe-back']
			}),
			ASlides.prototype.plugins.bridgeServiceWorker,
			ASlides.prototype.plugins.bridgeWebRTC({ // PeerJS plugin so one slide controls the rest
				peerSettings: {
					host: 'example-peerjs-server.com',
					secure: true,
					port: 9000,
					debug: 2,
					path:"/peerjs"
				}
			})
		]
	});

	if (location.search === '?presentation') {
		slideContainer.classList.add('presentation');
	}

	if (location.search === '?notes') {
		slideContainer.classList.add('hide-presentation');
	}

• markdownTransform: .* Converts the content of any dom element with a class of '.marked' into html using markdown syntax.

• slideController: .* Adds some buttons to the top of the screen for going in and out of presentation mode

• deepLinking: .* If the url contains a hash which matches a slide-id that slide gets displayed on load

• interactionKeyboard: .* Adds key controls for progressing to the next slide or going back to the previous

• interactionTouch: .* So one can swipe forward or back to previous slides.

• bridgeServiceWorker: .* Allows one open tab to control another so you can have notes on one display and the presentation on another. .* Requires a service worker set to echo some events, example:

	// Send a signal to all connected windows.
	// Used for service worker bridge in a-slides
	function reply(data) {
		return self.clients.matchAll({type: 'window'})
		.then(function (windows) {
			windows.forEach(function (w) {
				w.postMessage(data);
			});
		});
	}

	// Echo messages back to every window
	self.addEventListener('message', function(event) {
		reply(event.data);
	});

• bridgeWebRTC: .* Uses the peer.js library to connect to and control another client via WebRTC. Requires an existing peer.js signaling server.

Slide animations are defined as such:

{'slide-id': {
	setup() {},
	action: function *() {
		this.appendChild(window.MAKE.markdown('# Hello'));
		yield;
		this.appendChild(window.MAKE.markdown('# World'));
	},
	teardown: {
		this.innerHTML = '';
	}
}}

• Animations are defined as generators, when the yeild whenever you are awaiting an input from the presenter.
• setup is run and action are run when the slide is being moved into position.
• action's next() is called repeatedly with each input.
• teardown() is called after the slide has been hidden
• resetting a slide will run teardown() and reinitialise action()
• for a complex example see: https://github.com/AdaRoseEdwards/progressive-web-apps-talk/blob/gh-pages/scripts/content/LoaPN.js

• a-slides_slide-setup
• a-slides_slide-show
• a-slides_slide-teardown
• a-slides_refresh-slide (fireable)
• a-slides_next-slide (fireable)
• a-slides_previous-slide (fireable)
• a-slides_goto-slide (fireable)

// goto a slide by id or by dom element
slideContainer.fire('a-slides_goto-slide', {slide: 0});
slideContainer.fire('a-slides_goto-slide', {slide: document.querySelector('.a-slide')});

Todo

Example SCSS file: jekyll-template/styles/slides.scss