github

ageitgey / amplify

  • среда, 16 марта 2016 г. в 02:12:14
https://github.com/ageitgey/amplify

CSS
A Jekyll html theme in the vague style of Medium.com built using Google AMP



Amplify for Jekyll

A Jekyll html theme in the vague style of Medium.com built using Google AMP

Google's Accelerated Mobile Pages Project (a.k.a. "Google AMP" or Google ) is an open-source project that defines rules for creating websites that load nearly instantly even on mobile devices with slow connections.

Check out a live example of this theme at http://ageitgey.github.io/amplify/ or via Google's CDN.

Screenshot

screenshot

Why use Google AMP?

There are two reasons to use Google AMP:

First, it's really fast! An often cited claim (by Amazon, Yahoo, Walmart and others) is that every extra 100ms improvement in page load time increases incremental revenue by up to 1%. Your personal blog might not be selling anything, but why settle for a slow page and risk losing readers?

Second, Google might feature your AMP page in Search Results! Google gives preferential treatment to AMP pages on Mobile Search. When it displays your page in the AMP search results widget, it will even serve your page through it's own CDN to make the page load even faster. It's similar to how Facebook Instant Articles works on the Facebook platform.

How fast is this theme?

To get a general idea of how this theme performs, let's compare this page hosted on Github vs. another static page hosted on Github. We can use https://facebook.github.io/react/ as a comparison page. I've also included https://jekyllrb.com/ as another point of comparison (it's also hosted on Github).

Of course our page and these other pages have different layouts. But the main point is that they are typical static sites hosted on Github and are well-designed. So it should give us a rough idea of how other typical pages might perform. I'm not suggesting anything is wrong with these other pages. They are actually pretty fast!

If you are on a fast connection, all these pages load about the same speed but our page renders the main content much faster:

First page visit with no throttling

Page DOMContentReady Load
https://facebook.github.io/react/ 1.7s 1.89s
https://jekyllrb.com/ 500ms 909ms
https://ageitgey.github.io/amplify/2016/03/08/example-post.html 61ms! 1.06s

Second page visit with no throttling

Page DOMContentReady Load
https://facebook.github.io/react/ 1.08s 1.33s
https://jekyllrb.com/ 212ms 486ms
https://ageitgey.github.io/amplify/2016/03/08/example-post.html 66ms! 1.03s

You'll see the main content render much faster because AMP doesn't allow anything in your page that would block the page from rendering after the initial HTML loads. This means no external css, no custom js, etc.

Here's how this looks to the user (as rendered by WebPageTest):

screenshot

You can get sometimes get even faster speeds when your page is served via Google's AMP CDN. But that's not always true depending the randomness of the internet and where you are connecting from.

So there's some tiny benefit on a 100mbs wired connection. But optimization is much more important on a slow, high-latency mobile connection (i.e. most actual internet users in 2016). Let's try loading the page using the "Regular 2G (250kb/s, 300ms RT)" throttling setting in Chrome Dev Tools:

First page visit with "Regular 2G" throttling

Page DOMContentReady Load
https://facebook.github.io/react/ 28.50s 29.39s
https://jekyllrb.com/ 1.75s 7.03s
https://ageitgey.github.io/amplify/2016/03/08/example-post.html 530ms! 5.07s

Second page visit with "Regular 2G" throttling

Page DOMContentReady Load
https://facebook.github.io/react/ 2.02s 2.55s
https://jekyllrb.com/ 392ms 791ms
https://ageitgey.github.io/amplify/2016/03/08/example-post.html 385ms! 1.64s

Even a horribly slow connection with high latency, the user will still see a page render in half a second. That's great! The difference between 385ms and 28s is the different between someone reading your blog is skipping your blog.

But notice that the Jekyll homepage still performs well on the second page load. Google AMP gives you a nice set of rules for making fast pages, but of course it isn't required to make a fast page.

Getting Started

To use this theme, it's just like using any other Jekyll template:

Step 1: Install Jekyll

Step 2: Clone this repo to your computer

git clone <blah>

Step 3: Tweak _config.yml.

Just fill in everything in the # Site settings section. You'll want to set your site's title, your name, your twitter username, etc.

Step 4: Run jekyll serve and then open http://localhost:4000/ to see your site!

Step 5: Publish your site just like any other Jekyll site.

Google AMP Limitations

Google AMP sets many strict limits on what you can include in your web pages. A few of these are worth talking about:

Limitation: All CSS must be inline (no external css files).

Because of this, the main css file for this site is in _includes/styles.scss instead of in the normal css/ Jekyll folder. This css file is inlined into the header of every page via the special scssify filter in _includes/head.html.

Limitation: Size all resources statically

Every image you include in your page must have a height and width. This also applies to other things like embedding videos or other resources. Check below for more details.

Writing Posts with Google AMP

Writing posts works just like it does normally in Jekyll except when you want to include extra resources likes pictures, videos, embedded Twitter posts, etc.

Google AMP has it's own set of special html tags for including content. You should use these instead of normal Markdown or HTML tags.

The two you are are most likely to need are <amp-img> and <amp-youtube>:

Images in your posts

<amp-img width="600" height="300" layout="responsive" src="/assets/images/your_picture.jpg"></amp-img>

Youtube Videos in your posts

<amp-youtube data-videoid="NpEaa2P7qZI" layout="responsive" width="480" height="270"></amp-youtube>

Embedding other types of content

The AMP Project provides helpers for many other types of content like audio, ads, Google Analytics, etc.

Validating your page with Google AMP

Google AMP adds built-in validation logic to make sure your pages follow all the rules so they render as fast as possible.

To check your page, just add #development=1 to any url on your site and then check the javascript console in your browser.

http://localhost:4000/#development=1

You will either see a success message:

Powered by AMP ⚡ HTML – Version 1457112743399
AMP validation successful.

Or you will see a list of errors to fix:

Powered by AMP ⚡ HTML – Version 1457112743399
AMP validation had errors:
The attribute 'style' may not appear in tag 'span'
The attribute 'style' may not appear in tag 'div'

Making Google serve your page

Google will cache valid AMP pages if you link to them with one of these urls:

https://cdn.ampproject.org/c/s/<your page url here>

Or:

https://amp.gstatic.com/c/s/<your page url here>

But keep in mind these two limitations:

  1. The caches don't refresh that often. So don't view these urls until your page is done!
  2. Remove /s from both urls if your page isn't served over https://.

Required Schema Data

To actually get your page featured in Google search results, it needs to include a http://schema.org NewsArticle schema. See _includes/metadata.json for the version generated by default. You might want to tweak it.

Credits

This theme is inspired by Mediator by Dirk Fabisch. I used some of the css and html from that theme as a starting point. Thanks!

License

MIT. See LICENSE file in repo.